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# vmagent

`vmagent` is a tiny agent which helps you collect metrics from various sources,
[relabel and filter the collected metrics](#relabeling)
and store them in [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics)
or any other storage systems via Prometheus `remote_write` protocol.

See [Quick Start](#quick-start) for details.

<img alt="vmagent" src="vmagent.png">

## Motivation

While VictoriaMetrics provides an efficient solution to store and observe metrics, our users needed something fast
and RAM friendly to scrape metrics from Prometheus-compatible exporters into VictoriaMetrics.
Also, we found that our user's infrastructure are like snowflakes in that no two are alike. Therefore we decided to add more flexibility
to `vmagent` such as the ability to [accept metrics via popular push protocols](#how-to-push-data-to-vmagent)
additionally to [discovering Prometheus-compatible targets and scraping metrics from them](#how-to-collect-metrics-in-prometheus-format).

## Features

* Can be used as a drop-in replacement for Prometheus for discovering and scraping targets such as [node_exporter](https://github.com/prometheus/node_exporter).
  Note that single-node VictoriaMetrics can also discover and scrape Prometheus-compatible targets in the same way as `vmagent` does -
  see [these docs](https://docs.victoriametrics.com/#how-to-scrape-prometheus-exporters-such-as-node-exporter).
* Can add, remove and modify labels (aka tags) via Prometheus relabeling. Can filter data before sending it to remote storage. See [these docs](#relabeling) for details.
* Can accept data via all the ingestion protocols supported by VictoriaMetrics - see [these docs](#how-to-push-data-to-vmagent).
* Can replicate collected metrics simultaneously to multiple remote storage systems -
  see [these docs](#replication-and-high-availability).
* Works smoothly in environments with unstable connections to remote storage. If the remote storage is unavailable, the collected metrics
  are buffered at `-remoteWrite.tmpDataPath`. The buffered metrics are sent to remote storage as soon as the connection
  to the remote storage is repaired. The maximum disk usage for the buffer can be limited with `-remoteWrite.maxDiskUsagePerURL`.
* Uses lower amounts of RAM, CPU, disk IO and network bandwidth than Prometheus.
* Scrape targets can be spread among multiple `vmagent` instances when big number of targets must be scraped. See [these docs](#scraping-big-number-of-targets).
* Can load scrape configs from multiple files. See [these docs](#loading-scrape-configs-from-multiple-files).
* Can efficiently scrape targets that expose millions of time series such as [/federate endpoint in Prometheus](https://prometheus.io/docs/prometheus/latest/federation/).
  See [these docs](#stream-parsing-mode).
* Can deal with [high cardinality](https://docs.victoriametrics.com/FAQ.html#what-is-high-cardinality)
  and [high churn rate](https://docs.victoriametrics.com/FAQ.html#what-is-high-churn-rate) issues by limiting the number of unique time series at scrape time
  and before sending them to remote storage systems. See [these docs](#cardinality-limiter).
* Can write collected metrics to multiple tenants. See [these docs](#multitenancy).
* Can read data from Kafka. See [these docs](#reading-metrics-from-kafka).
* Can write data to Kafka. See [these docs](#writing-metrics-to-kafka).

## Quick Start

Please download `vmutils-*` archive from [releases page](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) (
`vmagent` is also available in [docker images](https://hub.docker.com/r/victoriametrics/vmagent/tags)),
unpack it and pass the following flags to the `vmagent` binary in order to start scraping Prometheus-compatible targets:

* `-promscrape.config` with the path to Prometheus config file (usually located at `/etc/prometheus/prometheus.yml`).
  The path can point either to local file or to http url. `vmagent` doesn't support some sections of Prometheus config file,
  so you may need either to delete these sections or to run `vmagent` with `-promscrape.config.strictParse=false` command-line flag.
  In this case `vmagent` ignores unsupported sections. See [the list of unsupported sections](#unsupported-prometheus-config-sections).
* `-remoteWrite.url` with the remote storage endpoint such as VictoriaMetrics, the `-remoteWrite.url` argument can be specified
  multiple times to replicate data concurrently to an arbitrary number of remote storage systems. See [various use cases](#use-cases).

Example command line:

```console
/path/to/vmagent -promscrape.config=/path/to/prometheus.yml -remoteWrite.url=https://victoria-metrics-host:8428/api/v1/write
```

See [how to scrape Prometheus-compatible targets](#how-to-collect-metrics-in-prometheus-format) for more details.

If you use single-node VictoriaMetrics, then you can discover and scrape Prometheus-compatible targets directly from VictoriaMetrics
without the need to use `vmagent` - see [these docs](https://docs.victoriametrics.com/#how-to-scrape-prometheus-exporters-such-as-node-exporter).

If you don't need to scrape Prometheus-compatible targets, then the `-promscrape.config` option isn't needed.
For example, the following command is sufficient for accepting data via [supported push-based protocols](#how-to-push-data-to-vmagent)
and sending it to the provided `-remoteWrite.url`:

```console
/path/to/vmagent -remoteWrite.url=https://victoria-metrics-host:8428/api/v1/write
```

See [troubleshooting docs](#troubleshooting) if you encounter common issues with `vmagent`.

Pass `-help` to `vmagent` in order to see [the full list of supported command-line flags with their descriptions](#advanced-usage).

## How to push data to vmagent

`vmagent` supports [the same set of push-based data ingestion protocols as VictoriaMetrics does](https://docs.victoriametrics.com/#how-to-import-time-series-data)
additionally to pull-based Prometheus-compatible targets' scraping:

* DataDog "submit metrics" API. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-send-data-from-datadog-agent).
* InfluxDB line protocol via `http://<vmagent>:8429/write`. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-send-data-from-influxdb-compatible-agents-such-as-telegraf).
* Graphite plaintext protocol if `-graphiteListenAddr` command-line flag is set. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-send-data-from-graphite-compatible-agents-such-as-statsd).
* OpenTSDB telnet and http protocols if `-opentsdbListenAddr` command-line flag is set. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-send-data-from-opentsdb-compatible-agents).
* Prometheus remote write protocol via `http://<vmagent>:8429/api/v1/write`.
* JSON lines import protocol via `http://<vmagent>:8429/api/v1/import`. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-data-in-json-line-format).
* Native data import protocol via `http://<vmagent>:8429/api/v1/import/native`. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-data-in-native-format).
* Prometheus exposition format via `http://<vmagent>:8429/api/v1/import/prometheus`. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-data-in-prometheus-exposition-format) for details.
* Arbitrary CSV data via `http://<vmagent>:8429/api/v1/import/csv`. See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-import-csv-data).

## Configuration update

`vmagent` should be restarted in order to update config options set via command-line args.
`vmagent` supports multiple approaches for reloading configs from updated config files such as
`-promscrape.config`, `-remoteWrite.relabelConfig` and `-remoteWrite.urlRelabelConfig`:

* Sending `SIGHUP` signal to `vmagent` process:

  ```console
  kill -SIGHUP `pidof vmagent`
  ```

* Sending HTTP request to `http://vmagent:8429/-/reload` endpoint.

There is also `-promscrape.configCheckInterval` command-line option, which can be used for automatic reloading configs from updated `-promscrape.config` file.

## Use cases

### IoT and Edge monitoring

`vmagent` can run and collect metrics in IoT environments and industrial networks with unreliable or scheduled connections to their remote storage.
It buffers the collected data in local files until the connection to remote storage becomes available and then sends the buffered
data to the remote storage. It re-tries sending the data to remote storage until errors are resolved.
The maximum on-disk size for the buffered metrics can be limited with `-remoteWrite.maxDiskUsagePerURL`.

`vmagent` works on various architectures from the IoT world - 32-bit arm, 64-bit arm, ppc64, 386, amd64.
See [the corresponding Makefile rules](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/app/vmagent/Makefile) for details.

### Drop-in replacement for Prometheus

If you use Prometheus only for scraping metrics from various targets and forwarding these metrics to remote storage
then `vmagent` can replace Prometheus. Typically, `vmagent` requires lower amounts of RAM, CPU and network bandwidth compared with Prometheus.
See [these docs](#how-to-collect-metrics-in-prometheus-format) for details.

### Flexible metrics relay

`vmagent` can accept metrics in [various popular data ingestion protocols](#how-to-push-data-to-vmagent), apply [relabeling](#relabeling)
to the accepted metrics (for example, change metric names/labels or drop unneeded metrics) and then forward the relabeled metrics
to other remote storage systems, which support Prometheus `remote_write` protocol (including other `vmagent` instances).

### Replication and high availability

`vmagent` replicates the collected metrics among multiple remote storage instances configured via `-remoteWrite.url` args.
If a single remote storage instance temporarily is out of service, then the collected data remains available in another remote storage instance.
`vmagent` buffers the collected data in files at `-remoteWrite.tmpDataPath` until the remote storage becomes available again
and then it sends the buffered data to the remote storage in order to prevent data gaps.

### Relabeling and filtering

`vmagent` can add, remove or update labels on the collected data before sending it to the remote storage. Additionally,
it can remove unwanted samples via Prometheus-like relabeling before sending the collected data to remote storage.
Please see [these docs](#relabeling) for details.

### Splitting data streams among multiple systems

`vmagent` supports splitting the collected data between multiple destinations with the help of `-remoteWrite.urlRelabelConfig`,
which is applied independently for each configured `-remoteWrite.url` destination. For example, it is possible to replicate or split
data among long-term remote storage, short-term remote storage and a real-time analytical system [built on top of Kafka](https://github.com/Telefonica/prometheus-kafka-adapter).
Note that each destination can receive it's own subset of the collected data due to per-destination relabeling via `-remoteWrite.urlRelabelConfig`.

### Prometheus remote_write proxy

`vmagent` can be used as a proxy for Prometheus data sent via Prometheus `remote_write` protocol. It can accept data via the `remote_write` API
at the`/api/v1/write` endpoint. Then apply relabeling and filtering and proxy it to another `remote_write` system .
The `vmagent` can be configured to encrypt the incoming `remote_write` requests with `-tls*` command-line flags.
Also, Basic Auth can be enabled for the incoming `remote_write` requests with `-httpAuth.*` command-line flags.

### remote_write for clustered version

While `vmagent` can accept data in several supported protocols (OpenTSDB, Influx, Prometheus, Graphite) and scrape data from various targets,
writes are always performed in Promethes remote_write protocol. Therefore for the [clustered version](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html),
the `-remoteWrite.url` command-line flag should be configured as `<schema>://<vminsert-host>:8480/insert/<accountID>/prometheus/api/v1/write`
according to [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format).
There is also support for multitenant writes. See [these docs](#multitenancy).

## Multitenancy

By default `vmagent` collects the data without tenant identifiers and routes it to the configured `-remoteWrite.url`.

[VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html) supports writing data to multiple tenants
specified via special labels - see [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy-via-labels).
This allows specifying tenant ids via [relabeling](#relabeling) and writing multitenant data
to a single `-remoteWrite.url=http://<vminsert-addr>/insert/multitenant/prometheus/api/v1/write`.

`vmagent` can accept data from the same multitenant endpoints as `vminsert` from [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html)
does according to [these docs](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format) and route the accepted data
to the corresponding [tenants](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy) in VictoriaMetrics cluster
pointed by the `-remoteWrite.multitenantURL` command-line flag. For example, if `-remoteWrite.multitenantURL` is set to `http://vminsert-service`,
then `vmagent` would accept multitenant data at `http://vmagent:8429/insert/<accountID>/...` endpoints in the same way
as [VictoriaMetrics cluster does](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#url-format) and route
it to `http://vminsert-service/insert/<accountID>/prometheus/api/v1/write`.

If multiple `-remoteWrite.multitenantURL` command-line options are set, then `vmagent` replicates the collected data across all the configured urls.
This allows using a single `vmagent` instance in front of multiple VictoriaMetrics clusters.

If `-remoteWrite.multitenantURL` command-line flag is set and `vmagent` is configured to scrape Prometheus-compatible targets
(e.g. if `-promscrape.config` command-line flag is set) then `vmagent` reads tenantID from `__tenant_id__` label
for the discovered targets and routes all the metrics from this target to the given `__tenant_id__`,
e.g. to the url `<-remoteWrite.multitnenatURL>/insert/<__tenant_id__>/prometheus/api/v1/write`.

For example, the following relabeling rule instructs sending metrics to tenantID defined in the `prometheus.io/tenant` annotation of Kubernetes pod deployment:

```yaml
scrape_configs:
- kubernetes_sd_configs:
  - role: pod
  relabel_configs:
  - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_tenant]
    target_label: __tenant_id__
```

If the target has no associated `__tenant_id__` label, then its' metrics are routed to zero tenantID, e.g. to `<-remoteWrite.multitenantURL>/insert/0/prometheus/api/v1/write`.

## How to collect metrics in Prometheus format

Specify the path to `prometheus.yml` file via `-promscrape.config` command-line flag. `vmagent` takes into account the following
sections from [Prometheus config file](https://prometheus.io/docs/prometheus/latest/configuration/configuration/):

* `global`
* `scrape_configs`

All other sections are ignored, including the [remote_write](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#remote_write) section.
Use `-remoteWrite.*` command-line flag instead for configuring remote write settings. See [the list of unsupported config sections](#unsupported-prometheus-config-sections).

The file pointed by `-promscrape.config` may contain `%{ENV_VAR}` placeholders which are substituted by the corresponding `ENV_VAR` environment variable values.

See [the list of supported service discovery types for Prometheus scrape targets](https://docs.victoriametrics.com/sd_configs.html).


## scrape_config enhancements

`vmagent` supports the following additional options in [scrape_configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) section:

* `headers` - a list of HTTP headers to send to scrape target with each scrape request. This can be used when the scrape target
  needs custom authorization and authentication. For example:

```yaml
scrape_configs:
- job_name: custom_headers
  headers:
  - "TenantID: abc"
  - "My-Auth: TopSecret"
```

* `disable_compression: true` for disabling response compression on a per-job basis. By default `vmagent` requests compressed responses
  from scrape targets for saving network bandwidth.
* `disable_keepalive: true` for disabling [HTTP keep-alive connections](https://en.wikipedia.org/wiki/HTTP_persistent_connection)
  on a per-job basis. By default `vmagent` uses keep-alive connections to scrape targets for reducing overhead on connection re-establishing.
* `series_limit: N` for limiting the number of unique time series a single scrape target can expose. See [these docs](#cardinality-limiter).
* `stream_parse: true` for scraping targets in a streaming manner. This may be useful when targets export big number of metrics. See [these docs](#stream-parsing-mode).
* `scrape_align_interval: duration` for aligning scrapes to the given interval instead of using random offset
  in the range `[0 ... scrape_interval]` for scraping each target. The random offset helps spreading scrapes evenly in time.
* `scrape_offset: duration` for specifying the exact offset for scraping instead of using random offset in the range `[0 ... scrape_interval]`.

See [scrape_configs docs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) for more details on all the supported options.


## Loading scrape configs from multiple files

`vmagent` supports loading [scrape configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) from multiple files specified
in the `scrape_config_files` section of `-promscrape.config` file. For example, the following `-promscrape.config` instructs `vmagent`
loading scrape configs from all the `*.yml` files under `configs` directory, from `single_scrape_config.yml` local file
and from `https://config-server/scrape_config.yml` url:

```yml
scrape_config_files:
- configs/*.yml
- single_scrape_config.yml
- https://config-server/scrape_config.yml
```

Every referred file can contain arbitrary number of [supported scrape configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs).
There is no need in specifying top-level `scrape_configs` section in these files. For example:

```yml
- job_name: foo
  static_configs:
  - targets: ["vmagent:8429"]
- job_name: bar
  kubernetes_sd_configs:
  - role: pod
```

`vmagent` is able to dynamically reload these files - see [these docs](#configuration-update).

## Unsupported Prometheus config sections

`vmagent` doesn't support the following sections in Prometheus config file passed to `-promscrape.config` command-line flag:

* [remote_write](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#remote_write). This section is substituted
  with various `-remoteWrite*` command-line flags. See [the full list of flags](#advanced-usage). The `remote_write` section isn't supported
  in order to reduce possible confusion when `vmagent` is used for accepting incoming metrics via [supported push protocols](#how-to-push-data-to-vmagent).
  In this case the `-promscrape.config` file isn't needed.
* `remote_read`. This section isn't supported at all, since `vmagent` doesn't provide Prometheus querying API.
  It is expected that the querying API is provided by the remote storage specified via `-remoteWrite.url` such as VictoriaMetrics.
  See [Prometheus querying API docs for VictoriaMetrics](https://docs.victoriametrics.com/#prometheus-querying-api-usage).
* `rule_files` and `alerting`. These sections are supported by [vmalert](https://docs.victoriametrics.com/vmalert.html).

The list of supported service discovery types is available [here](#how-to-collect-metrics-in-prometheus-format).

Additionally `vmagent` doesn't support `refresh_interval` option at service discovery sections.
This option is substituted with `-promscrape.*CheckInterval` command-line options, which are specific per each service discovery type.
See [the full list of command-line flags for vmagent](#advanced-usage).

## Adding labels to metrics

Extra labels can be added to metrics collected by `vmagent` via the following mechanisms:

* The `global -> external_labels` section in `-promscrape.config` file. These labels are added only to metrics scraped from targets configured
  in the `-promscrape.config` file. They aren't added to metrics collected via other [data ingestion protocols](#how-to-push-data-to-vmagent).
* The `-remoteWrite.label` command-line flag. These labels are added to all the collected metrics before sending them to `-remoteWrite.url`.
  For example, the following command starts `vmagent`, which adds `{datacenter="foobar"}` label to all the metrics pushed
  to all the configured remote storage systems (all the `-remoteWrite.url` flag values):

  ```
  /path/to/vmagent -remoteWrite.label=datacenter=foobar ...
  ```

* Via relabeling. See [these docs](#relabeling).


## Automatically generated metrics

`vmagent` automatically generates the following metrics per each scrape of every [Prometheus-compatible target](#how-to-collect-metrics-in-prometheus-format)
and attaches target-specific `instance` and `job` labels to these metrics:

* `up` - this metric exposes `1` value on successful scrape and `0` value on unsuccessful scrape. This allows monitoring
  failing scrapes with the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html):

  ```metricsql
  up == 0
  ```

* `scrape_duration_seconds` - the duration of the scrape for the given target. This allows monitoring slow scrapes.
  For example, the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html) returns scrapes,
  which take more than 1.5 seconds to complete:

  ```metricsql
  scrape_duration_seconds > 1.5
  ```

* `scrape_timeout_seconds` - the configured timeout for the current scrape target (aka `scrape_timeout`).
  This allows detecting targets with scrape durations close to the configured scrape timeout.
  For example, the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html) returns targets (identified by `instance` label),
  which take more than 80% of the configured `scrape_timeout` during scrapes:

  ```metricsql
  scrape_duration_seconds / scrape_timeout_seconds > 0.8
  ```

* `scrape_samples_scraped` - the number of samples (aka metrics) parsed per each scrape. This allows detecting targets,
  which expose too many metrics. For example, the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html)
  returns targets, which expose more than 10000 metrics:

  ```metricsql
  scrape_samples_scraped > 10000
  ```

* `scrape_samples_limit` - the configured limit on the number of metrics the given target can expose.
  The limit can be set via `sample_limit` option at [scrape_configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs).
  This metric is exposed only if the `sample_limit` is set. This allows detecting targets,
  which expose too many metrics compared to the configured `sample_limit`. For example, the following query
  returns targets (identified by `instance` label), which expose more than 80% metrics compared to the configed `sample_limit`:

  ```metricsql
  scrape_samples_scraped / scrape_samples_limit > 0.8
  ```

* `scrape_samples_post_metric_relabeling` - the number of samples (aka metrics) left after applying metric-level relabeling
  from `metric_relabel_configs` section (see [relabeling docs](#relabeling) for more details).
  This allows detecting targets with too many metrics after the relabeling.
  For example, the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html) returns targets
  with more than 10000 metrics after the relabeling:

  ```metricsql
  scrape_samples_post_metric_relabeling > 10000
  ```

* `scrape_series_added` - **an approximate** number of new series the given target generates during the current scrape.
  This metric allows detecting targets (identified by `instance` label),
  which lead to [high churn rate](https://docs.victoriametrics.com/FAQ.html#what-is-high-churn-rate).
  For example, the following [MetricsQL query](https://docs.victoriametrics.com/MetricsQL.html) returns targets,
  which generate more than 1000 new series during the last hour:

  ```metricsql
  sum_over_time(scrape_series_added[1h]) > 1000
  ```

  `vmagent` sets `scrape_series_added` to zero when it runs with `-promscrape.noStaleMarkers` command-line option
  or when it scrapes target with `no_stale_markers: true` option, e.g. when [staleness markers](#prometheus-staleness-markers) are disabled.

* `scrape_series_limit` - the limit on the number of unique time series the given target can expose according to [these docs](#cardinality-limiter).
  This metric is exposed only if the series limit is set.

* `scrape_series_current` - the number of unique series the given target exposed so far.
  This metric is exposed only if the series limit is set according to [these docs](#cardinality-limiter).
  This metric allows alerting when the number of exposed series by the given target reaches the limit.
  For example, the following query would alert when the target exposes more than 90% of unique series compared to the configured limit.

  ```metricsql
  scrape_series_current / scrape_series_limit > 0.9
  ```

* `scrape_series_limit_samples_dropped` - exposes the number of dropped samples during the scrape because of the exceeded limit
  on the number of unique series. This metric is exposed only if the series limit is set according to [these docs](#cardinality-limiter).
  This metric allows alerting when scraped samples are dropped because of the exceeded limit.
  For example, the following query alerts when at least a single sample is dropped because of the exceeded limit during the last hour:

  ```metricsql
  sum_over_time(scrape_series_limit_samples_dropped[1h]) > 0
  ```

If the target exports metrics with names clashing with the automatically generated metric names, then `vmagent` automatically
adds `exported_` prefix to these metric names, so they don't clash with automatically generated metric names.


## Relabeling

VictoriaMetrics components support [Prometheus-compatible relabeling](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config)
with [additional enhancements](#relabeling-enhancements). The relabeling can be defined in the following places processed by `vmagent`:

* At the `scrape_config -> relabel_configs` section in `-promscrape.config` file.
  This relabeling is used for modifying labels in discovered targets and for dropping unneded targets.
  See [relabeling cookbook](https://docs.victoriametrics.com/relabeling.html) for details.

  This relabeling can be debugged by clicking the `debug` link at the corresponding target on the `http://vmagent:8429/targets` page
  or on the `http://vmagent:8429/service-discovery` page. See [these docs](#relabel-debug) for details.

* At the `scrape_config -> metric_relabel_configs` section in `-promscrape.config` file.
  This relabeling is used for modifying labels in scraped metrics and for dropping unneeded metrics.
  See [relabeling cookbook](https://docs.victoriametrics.com/relabeling.html) for details.

  This relabeling can be debugged via `http://vmagent:8429/metric-relabel-debug` page. See [these docs](#relabel-debug) for details.

* At the `-remoteWrite.relabelConfig` file. This relabeling is used for modifying labels for all the collected metrics
  (including [metrics obtained via push-based protocols](#how-to-push-data-to-vmagent)) and for dropping unneeded metrics
  before sending them to all the configured `-remoteWrite.url` addresses.

  This relabeling can be debugged via `http://vmagent:8429/metric-relabel-debug` page. See [these docs](#relabel-debug) for details.

* At the `-remoteWrite.urlRelabelConfig` files. This relabeling is used for modifying labels for metrics
  and for dropping unneeded metrics before sending them to a particular `-remoteWrite.url`.

  This relabeling can be debugged via `http://vmagent:8429/metric-relabel-debug` page. See [these docs](#relabel-debug) for details.

All the files with relabeling configs can contain special placeholders in the form `%{ENV_VAR}`,
which are replaced by the corresponding environment variable values.

The following articles contain useful information about Prometheus relabeling:

* [Cookbook for common relabeling tasks](https://docs.victoriametrics.com/relabeling.html)
* [How to use Relabeling in Prometheus and VictoriaMetrics](https://valyala.medium.com/how-to-use-relabeling-in-prometheus-and-victoriametrics-8b90fc22c4b2)
* [Life of a label](https://www.robustperception.io/life-of-a-label)
* [Discarding targets and timeseries with relabeling](https://www.robustperception.io/relabelling-can-discard-targets-timeseries-and-alerts)
* [Dropping labels at scrape time](https://www.robustperception.io/dropping-metrics-at-scrape-time-with-prometheus)
* [Extracting labels from legacy metric names](https://www.robustperception.io/extracting-labels-from-legacy-metric-names)
* [relabel_configs vs metric_relabel_configs](https://www.robustperception.io/relabel_configs-vs-metric_relabel_configs)

## Relabeling enhancements

`vmagent` provides the following enhancements on top of Prometheus-compatible relabeling:

* The `replacement` option can refer arbitrary labels via {% raw %}`{{label_name}}`{% endraw %} placeholders.
  Such placeholders are substituted with the corresponding label value. For example, the following relabeling rule
  sets `instance-job` label value to `host123-foo` when applied to the metric with `{instance="host123",job="foo"}` labels:

  {% raw %}
  ```yaml
  - target_label: "instance-job"
    replacement: "{{instance}}-{{job}}"
  ```
  {% endraw %}

* An optional `if` filter can be used for conditional relabeling. The `if` filter may contain
  arbitrary [time series selector](https://prometheus.io/docs/prometheus/latest/querying/basics/#time-series-selectors).
  For example, the following relabeling rule drops metrics, which don't match `foo{bar="baz"}` series selector, while leaving the rest of metrics:

  ```yaml
  - if: 'foo{bar="baz"}'
    action: keep
  ```

  This is equivalent to less clear Prometheus-compatible relabeling rule:

  ```yaml
  - action: keep
    source_labels: [__name__, bar]
    regex: 'foo;baz'
  ```

* The `regex` value can be split into multiple lines for improved readability and maintainability.
  These lines are automatically joined with `|` char when parsed. For example, the following configs are equivalent:

  ```yaml
  - action: keep_metrics
    regex: "metric_a|metric_b|foo_.+"
  ```

  ```yaml
  - action: keep_metrics
    regex:
    - "metric_a"
    - "metric_b"
    - "foo_.+"
  ```

* VictoriaMetrics provides the following additional relabeling actions on top of standard actions
  from the [Prometheus relabeling](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config):

  * `replace_all` replaces all of the occurrences of `regex` in the values of `source_labels` with the `replacement`
    and stores the results in the `target_label`. For example, the following relabeling config replaces all the occurrences
    of `-` char in metric names with `_` char (e.g. `foo-bar-baz` metric name is transformed into `foo_bar_baz`):

    ```yaml
    - action: replace_all
      source_labels: ["__name__"]
      target_label: "__name__"
      regex: "-"
      replacement: "_"
    ```

  * `labelmap_all` replaces all of the occurrences of `regex` in all the label names with the `replacement`.
    For example, the following relabeling config replaces all the occurrences of `-` char in all the label names
    with `_` char (e.g. `foo-bar-baz` label name is transformed into `foo_bar_baz`):

    ```yaml
    - action: labelmap_all
      regex: "-"
      replacement: "_"
    ```

  * `keep_if_equal`: keeps the entry if all the label values from `source_labels` are equal,
    while dropping all the other entries. For example, the following relabeling config keeps targets
    if they contain equal values for `instance` and `host` labels, while dropping all the other targets:

    ```yaml
    - action: keep_if_equal
      source_labels: ["instance", "host"]
    ```

  * `drop_if_equal`: drops the entry if all the label values from `source_labels` are equal,
    while keeping all the other entries. For example, the following relabeling config drops targets
    if they contain equal values for `instance` and `host` labels, while keeping all the other targets:

    ```yaml
    - action: drop_if_equal
      source_labels: ["instance", "host"]
    ```

  * `keep_metrics`: keeps all the metrics with names matching the given `regex`,
    while dropping all the other metrics. For example, the following relabeling config keeps metrics
    with `foo` and `bar` names, while dropping all the other metrics:

    ```yaml
    - action: keep_metrics
      regex: "foo|bar"
    ```

  * `drop_metrics`: drops all the metrics with names matching the given `regex`, while keeping all the other metrics.
    For example, the following relabeling config drops metrics with `foo` and `bar` names, while leaving all the other metrics:

    ```yaml
    - action: drop_metrics
      regex: "foo|bar"
    ```

  * `graphite`: applies Graphite-style relabeling to metric name. See [these docs](#graphite-relabeling) for details.

## Graphite relabeling

VictoriaMetrics components support `action: graphite` relabeling rules, which allow extracting various parts from Graphite-style metrics
into the configured labels with the syntax similar to [Glob matching in statsd_exporter](https://github.com/prometheus/statsd_exporter#glob-matching).
Note that the `name` field must be substituted with explicit `__name__` option under `labels` section.
If `__name__` option is missing under `labels` section, then the original Graphite-style metric name is left unchanged.

For example, the following relabeling rule generates `requests_total{job="app42",instance="host124:8080"}` metric
from "app42.host123.requests.total" Graphite-style metric:

```yaml
- action: graphite
  match: "*.*.*.total"
  labels:
    __name__: "${3}_total"
    job: "$1"
    instance: "${2}:8080"
```

Important notes about `action: graphite` relabeling rules:

- The relabeling rule is applied only to metrics, which match the given `match` expression. Other metrics remain unchanged.
- The `*` matches the maximum possible number of chars until the next dot or until the next part of the `match` expression whichever comes first.
  It may match zero chars if the next char is `.`.
  For example, `match: "app*foo.bar"` matches `app42foo.bar` and `42` becomes available to use at `labels` section via `$1` capture group.
- The `$0` capture group matches the original metric name.
- The relabeling rules are executed in order defined in the original config.

The `action: graphite` relabeling rules are easier to write and maintain than `action: replace` for labels extraction from Graphite-style metric names.
Additionally, the `action: graphite` relabeling rules usually work much faster than the equivalent `action: replace` rules.

## Relabel debug

`vmagent` and [single-node VictoriaMetrics](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html)
provide the following tools for debugging target-level and metric-level relabeling:

- Target-level relabeling (e.g. `relabel_configs` section at [scrape_configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs))
  can be performed by navigating to `http://vmagent:8429/targets` page (`http://victoriametrics:8428/targets` page for single-node VictoriaMetrics)
  and clicking the `debug` link at the target, which must be debugged.
  The opened page will show step-by-step results for the actual relabeling rules applied to the target labels.

  The `http://vmagent:8429/targets` page shows only active targets. If you need to understand why some target
  is dropped during the relabeling, then navigate to `http://vmagent:8428/service-discovery` page
  (`http://victoriametrics:8428/service-discovery` for single-node VictoriaMetrics), find the dropped target
  and click the `debug` link there. The opened page will show step-by-step results for the actual relabeling rules,
  which result to target drop.

- Metric-level relabeling (e.g. `metric_relabel_configs` section at [scrape_configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs)
  and all the relabeling, which can be set up via `-relabelConfig`, `-remoteWrite.relabelConfig` and `-remoteWrite.urlRelabelConfig`
  command-line flags) can be performed by navigating to `http://vmagent:8429/metric-relabel-debug` page
  (`http://victoriametrics:8428/metric-relabel-debug` page for single-node VictoriaMetrics)
  and submitting there relabeling rules together with the metric to be relabeled.
  The page will show step-by-step results for the entered relabeling rules executed against the entered metric.

## Prometheus staleness markers

`vmagent` sends [Prometheus staleness markers](https://www.robustperception.io/staleness-and-promql) to `-remoteWrite.url` in the following cases:

* If they are passed to `vmagent` via [Prometheus remote_write protocol](#prometheus-remote_write-proxy).
* If the metric disappears from the list of scraped metrics, then stale marker is sent to this particular metric.
* If the scrape target becomes temporarily unavailable, then stale markers are sent for all the metrics scraped from this target.
* If the scrape target is removed from the list of targets, then stale markers are sent for all the metrics scraped from this target.

Prometheus staleness markers' tracking needs additional memory, since it must store the previous response body per each scrape target
in order to compare it to the current response body. The memory usage may be reduced by disabling staleness tracking in the following ways:

* By passing `-promscrape.noStaleMarkers` command-line flag to `vmagent`. This disables staleness tracking across all the targets.
* By specifying `no_stale_markers: true` option in the [scrape_config](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) for the corresponding target.

When staleness tracking is disabled, then `vmagent` doesn't track the number of new time series per each scrape,
e.g. it sets `scrape_series_added` metric to zero. See [these docs](#automatically-generated-metrics) for details.

## Stream parsing mode

By default `vmagent` reads the full response body from scrape target into memory, then parses it, applies [relabeling](#relabeling)
and then pushes the resulting metrics to the configured `-remoteWrite.url`. This mode works good for the majority of cases
when the scrape target exposes small number of metrics (e.g. less than 10 thousand). But this mode may take big amounts of memory
when the scrape target exposes big number of metrics. In this case it is recommended enabling stream parsing mode.
When this mode is enabled, then `vmagent` reads response from scrape target in chunks, then immediately processes every chunk
and pushes the processed metrics to remote storage. This allows saving memory when scraping targets that expose millions of metrics.

Stream parsing mode is automatically enabled for scrape targets returning response bodies with sizes bigger than
the `-promscrape.minResponseSizeForStreamParse` command-line flag value. Additionally,
stream parsing mode can be explicitly enabled in the following places:

* Via `-promscrape.streamParse` command-line flag. In this case all the scrape targets defined
  in the file pointed by `-promscrape.config` are scraped in stream parsing mode.
* Via `stream_parse: true` option at `scrape_configs` section. In this case all the scrape targets defined
  in this section are scraped in stream parsing mode.
* Via `__stream_parse__=true` label, which can be set via [relabeling](#relabeling) at `relabel_configs` section.
  In this case stream parsing mode is enabled for the corresponding scrape targets.
  Typical use case: to set the label via [Kubernetes annotations](https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/)
  for targets exposing big number of metrics.

Examples:

```yml
scrape_configs:
- job_name: 'big-federate'
  stream_parse: true
  static_configs:
  - targets:
    - big-prometeus1
    - big-prometeus2
  honor_labels: true
  metrics_path: /federate
  params:
    'match[]': ['{__name__!=""}']
```

Note that `vmagent` in stream parsing mode stores up to `sample_limit` samples to the configured `-remoteStorage.url`
instead of droping all the samples read from the target, because the parsed data is sent to the remote storage
as soon as it is parsed in stream parsing mode.

## Scraping big number of targets

A single `vmagent` instance can scrape tens of thousands of scrape targets. Sometimes this isn't enough due to limitations on CPU, network, RAM, etc.
In this case scrape targets can be split among multiple `vmagent` instances (aka `vmagent` horizontal scaling, sharding and clustering).
Each `vmagent` instance in the cluster must use identical `-promscrape.config` files with distinct `-promscrape.cluster.memberNum` values.
The flag value must be in the range `0 ... N-1`, where `N` is the number of `vmagent` instances in the cluster.
The number of `vmagent` instances in the cluster must be passed to `-promscrape.cluster.membersCount` command-line flag. For example, the following commands
spread scrape targets among a cluster of two `vmagent` instances:

```
/path/to/vmagent -promscrape.cluster.membersCount=2 -promscrape.cluster.memberNum=0 -promscrape.config=/path/to/config.yml ...
/path/to/vmagent -promscrape.cluster.membersCount=2 -promscrape.cluster.memberNum=1 -promscrape.config=/path/to/config.yml ...
```

The `-promscrape.cluster.memberNum` can be set to a StatefulSet pod name when `vmagent` runs in Kubernetes.
The pod name must end with a number in the range `0 ... promscrape.cluster.memberNum-1`. For example, `-promscrape.cluster.memberNum=vmagent-0`.

By default each scrape target is scraped only by a single `vmagent` instance in the cluster. If there is a need for replicating scrape targets among multiple `vmagent` instances,
then `-promscrape.cluster.replicationFactor` command-line flag must be set to the desired number of replicas. For example, the following commands
start a cluster of three `vmagent` instances, where each target is scraped by two `vmagent` instances:

```
/path/to/vmagent -promscrape.cluster.membersCount=3 -promscrape.cluster.replicationFactor=2 -promscrape.cluster.memberNum=0 -promscrape.config=/path/to/config.yml ...
/path/to/vmagent -promscrape.cluster.membersCount=3 -promscrape.cluster.replicationFactor=2 -promscrape.cluster.memberNum=1 -promscrape.config=/path/to/config.yml ...
/path/to/vmagent -promscrape.cluster.membersCount=3 -promscrape.cluster.replicationFactor=2 -promscrape.cluster.memberNum=2 -promscrape.config=/path/to/config.yml ...
```

If each target is scraped by multiple `vmagent` instances, then data deduplication must be enabled at remote storage pointed by `-remoteWrite.url`.
The `-dedup.minScrapeInterval` must be set to the `scrape_interval` configured at `-promscrape.config`.
See [these docs](https://docs.victoriametrics.com/#deduplication) for details.

## High availability

It is possible to run multiple identically configured `vmagent` instances or `vmagent` [clusters](#scraping-big-number-of-targets),
so they [scrape](#how-to-collect-metrics-in-prometheus-format) the same set of targets and push the collected data to the same set of VictoriaMetrics remote storage systems.

In this case the deduplication must be configured at VictoriaMetrics in order to de-duplicate samples received from multiple identically configured `vmagent` instances or clusters.
See [these docs](https://docs.victoriametrics.com/#deduplication) for details.

It is also recommended passing different values to `-promscrape.cluster.name` command-line flag per each `vmagent` instance or per each `vmagent` cluster in HA setup.
This is needed for proper data de-duplication. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2679) for details.

## Scraping targets via a proxy

`vmagent` supports scraping targets via http, https and socks5 proxies. Proxy address must be specified in `proxy_url` option. For example, the following scrape config instructs
target scraping via https proxy at `https://proxy-addr:1234`:

```yml
scrape_configs:
- job_name: foo
  proxy_url: https://proxy-addr:1234
```

Proxy can be configured with the following optional settings:

* `proxy_authorization` for generic token authorization. See [these docs](https://docs.victoriametrics.com/sd_configs.html#http-api-client-options).
* `proxy_basic_auth` for Basic authorization. See [these docs](https://docs.victoriametrics.com/sd_configs.html#http-api-client-options).
* `proxy_bearer_token` and `proxy_bearer_token_file` for Bearer token authorization
* `proxy_oauth2` for OAuth2 config. See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#oauth2).
* `proxy_tls_config` for TLS config. See [these docs](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#tls_config).
* `proxy_headers` for passing additional HTTP headers in requests to proxy.

For example:

```yml
scrape_configs:
- job_name: foo
  proxy_url: https://proxy-addr:1234
  proxy_basic_auth:
    username: foobar
    password: secret
  proxy_tls_config:
    insecure_skip_verify: true
    cert_file: /path/to/cert
    key_file: /path/to/key
    ca_file: /path/to/ca
    server_name: real-server-name
  proxy_headers:
  - "Proxy-Auth: top-secret"
```

## Cardinality limiter

By default `vmagent` doesn't limit the number of time series each scrape target can expose. The limit can be enforced in the following places:

* Via `-promscrape.seriesLimitPerTarget` command-line option. This limit is applied individually
  to all the scrape targets defined in the file pointed by `-promscrape.config`.
* Via `series_limit` config option at [scrape_config](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) section.
  This limit is applied individually to all the scrape targets defined in the given `scrape_config`.
* Via `__series_limit__` label, which can be set with [relabeling](#relabeling) at `relabel_configs` section.
  This limit is applied to the corresponding scrape targets. Typical use case: to set the limit
  via [Kubernetes annotations](https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/) for targets,
  which may expose too high number of time series.

See also `sample_limit` option at [scrape_config section](https://docs.victoriametrics.com/sd_configs.html#scrape_configs).

Scraped metrics are dropped for time series exceeding the given limit.

`vmagent` creates the following additional per-target metrics for targets with non-zero series limit:

- `scrape_series_limit_samples_dropped` - the number of dropped samples during the scrape when the unique series limit is exceeded.
- `scrape_series_limit` - the series limit for the given target.
- `scrape_series_current` - the current number of series for the given target.

These metrics are automatically sent to the configured `-remoteWrite.url` alongside with the scraped per-target metrics.

These metrics allow building the following alerting rules:

- `scrape_series_current / scrape_series_limit > 0.9` - alerts when the number of series exposed by the target reaches 90% of the limit.
- `sum_over_time(scrape_series_limit_samples_dropped[1h]) > 0` - alerts when some samples are dropped because the series limit on a particular target is reached.


By default `vmagent` doesn't limit the number of time series written to remote storage systems specified at `-remoteWrite.url`.
The limit can be enforced by setting the following command-line flags:

* `-remoteWrite.maxHourlySeries` - limits the number of unique time series `vmagent` can write to remote storage systems during the last hour.
  Useful for limiting the number of active time series.
* `-remoteWrite.maxDailySeries` - limits the number of unique time series `vmagent` can write to remote storage systems during the last day.
  Useful for limiting daily churn rate.

Both limits can be set simultaneously. If any of these limits is reached, then samples for new time series are dropped instead of sending
them to remote storage systems. A sample of dropped series is put in the log with `WARNING` level.

`vmagent` exposes the following metrics at `http://vmagent:8429/metrics` page (see [monitoring docs](#monitoring) for details):

* `vmagent_hourly_series_limit_rows_dropped_total` - the number of metrics dropped due to exceeded hourly limit on the number of unique time series.
* `vmagent_hourly_series_limit_max_series` - the hourly series limit set via `-remoteWrite.maxHourlySeries`.
* `vmagent_hourly_series_limit_current_series` - the current number of unique series registered during the last hour.
* `vmagent_daily_series_limit_rows_dropped_total` - the number of metrics dropped due to exceeded daily limit on the number of unique time series.
* `vmagent_daily_series_limit_max_series` - the daily series limit set via `-remoteWrite.maxDailySeries`.
* `vmagent_daily_series_limit_current_series` - the current number of unique series registered during the last day.

These limits are approximate, so `vmagent` can underflow/overflow the limit by a small percentage (usually less than 1%).

See also [cardinality explorer docs](https://docs.victoriametrics.com/#cardinality-explorer).

## Monitoring

`vmagent` exports various metrics in Prometheus exposition format at `http://vmagent-host:8429/metrics` page.
We recommend setting up regular scraping of this page either through `vmagent` itself or by Prometheus
so that the exported metrics may be analyzed later.

Use official [Grafana dashboard](https://grafana.com/grafana/dashboards/12683) for `vmagent` state overview.
Graphs on this dashboard contain useful hints - hover the `i` icon at the top left corner of each graph in order to read it.
If you have suggestions for improvements or have found a bug - please open an issue on github or add a review to the dashboard.

`vmagent` also exports the status for various targets at the following pages:

* `http://vmagent-host:8429/targets`. This pages shows the current status for every active target.
* `http://vmagent-host:8429/service-discovery`. This pages shows the list of discovered targets with the discovered `__meta_*` labels
  according to [these docs](https://docs.victoriametrics.com/sd_configs.html).
  This page may help debugging target [relabeling](#relabeling).
* `http://vmagent-host:8429/api/v1/targets`. This handler returns JSON response
  compatible with [the corresponding page from Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/#targets).
* `http://vmagent-host:8429/ready`. This handler returns http 200 status code when `vmagent` finishes
  it's initialization for all the [service_discovery configs](https://docs.victoriametrics.com/sd_configs.html).
  It may be useful to perform `vmagent` rolling update without any scrape loss.

## Troubleshooting

* We recommend you [set up the official Grafana dashboard](#monitoring) in order to monitor the state of `vmagent'.

* We recommend you increase the maximum number of open files in the system (`ulimit -n`) when scraping a big number of targets,
  as `vmagent` establishes at least a single TCP connection per target.

* If `vmagent` uses too big amounts of memory, then the following options can help:
  * Disabling staleness tracking with `-promscrape.noStaleMarkers` option. See [these docs](#prometheus-staleness-markers).
  * Enabling stream parsing mode if `vmagent` scrapes targets with millions of metrics per target. See [these docs](#stream-parsing-mode).
  * Reducing the number of output queues with `-remoteWrite.queues` command-line option.
  * Reducing the amounts of RAM vmagent can use for in-memory buffering with `-memory.allowedPercent` or `-memory.allowedBytes` command-line option.
    Another option is to reduce memory limits in Docker and/or Kubernetes if `vmagent` runs under these systems.
  * Reducing the number of CPU cores vmagent can use by passing `GOMAXPROCS=N` environment variable to `vmagent`,
    where `N` is the desired limit on CPU cores. Another option is to reduce CPU limits in Docker or Kubernetes if `vmagent` runs under these systems.
  * Passing `-promscrape.dropOriginalLabels` command-line option to `vmagent`, so it drops `"discoveredLabels"` and `"droppedTargets"`
    lists at `/api/v1/targets` page. This reduces memory usage when scraping big number of targets at the cost
    of reduced debuggability for improperly configured per-target relabeling.

* When `vmagent` scrapes many unreliable targets, it can flood the error log with scrape errors. These errors can be suppressed
  by passing `-promscrape.suppressScrapeErrors` command-line flag to `vmagent`. The most recent scrape error per each target can be observed at `http://vmagent-host:8429/targets`
  and `http://vmagent-host:8429/api/v1/targets`.

* The `/service-discovery` page could be useful for debugging relabeling process for scrape targets.
  This page contains original labels for targets dropped during relabeling.
  By default the `-promscrape.maxDroppedTargets` targets are shown here. If your setup drops more targets during relabeling,
  then increase `-promscrape.maxDroppedTargets` command-line flag value to see all the dropped targets.
  Note that tracking each dropped target requires up to 10Kb of RAM. Therefore big values for `-promscrape.maxDroppedTargets`
  may result in increased memory usage if a big number of scrape targets are dropped during relabeling.

* We recommend you increase `-remoteWrite.queues` if `vmagent_remotewrite_pending_data_bytes` metric exported
  at `http://vmagent-host:8429/metrics` page grows constantly. It is also recommended increasing `-remoteWrite.maxBlockSize`
  and `-remoteWrite.maxRowsPerBlock` command-line options in this case. This can improve data ingestion performance
  to the configured remote storage systems at the cost of higher memory usage.

* If you see gaps in the data pushed by `vmagent` to remote storage when `-remoteWrite.maxDiskUsagePerURL` is set,
  try increasing `-remoteWrite.queues`. Such gaps may appear because `vmagent` cannot keep up with sending the collected data to remote storage.
  Therefore it starts dropping the buffered data if the on-disk buffer size exceeds `-remoteWrite.maxDiskUsagePerURL`.

* `vmagent` drops data blocks if remote storage replies with `400 Bad Request` and `409 Conflict` HTTP responses.
  The number of dropped blocks can be monitored via `vmagent_remotewrite_packets_dropped_total` metric exported at [/metrics page](#monitoring).

* Use `-remoteWrite.queues=1` when `-remoteWrite.url` points to remote storage, which doesn't accept out-of-order samples (aka data backfilling).
  Such storage systems include Prometheus, Cortex and Thanos, which typically emit `out of order sample` errors.
  The best solution is to use remote storage with [backfilling support](https://docs.victoriametrics.com/#backfilling) such as VictoriaMetrics.

* `vmagent` buffers scraped data at the `-remoteWrite.tmpDataPath` directory until it is sent to `-remoteWrite.url`.
  The directory can grow large when remote storage is unavailable for extended periods of time and if `-remoteWrite.maxDiskUsagePerURL` isn't set.
  If you don't want to send all the data from the directory to remote storage then simply stop `vmagent` and delete the directory.

* By default `vmagent` masks `-remoteWrite.url` with `secret-url` values in logs and at `/metrics` page because
  the url may contain sensitive information such as auth tokens or passwords.
  Pass `-remoteWrite.showURL` command-line flag when starting `vmagent` in order to see all the valid urls.

* By default `vmagent` evenly spreads scrape load in time. If a particular scrape target must be scraped at the beginning of some interval,
  then `scrape_align_interval` option  must be used. For example, the following config aligns hourly scrapes to the beginning of hour:

  ```yml
  scrape_configs:
  - job_name: foo
    scrape_interval: 1h
    scrape_align_interval: 1h
  ```

* By default `vmagent` evenly spreads scrape load in time. If a particular scrape target must be scraped at specific offset, then `scrape_offset` option must be used.
  For example, the following config instructs `vmagent` to scrape the target at 10 seconds of every minute:

  ```yml
  scrape_configs:
  - job_name: foo
    scrape_interval: 1m
    scrape_offset: 10s
  ```

* If you see `skipping duplicate scrape target with identical labels` errors when scraping Kubernetes pods, then it is likely these pods listen to multiple ports
  or they use an init container. These errors can either be fixed or suppressed with the `-promscrape.suppressDuplicateScrapeTargetErrors` command-line flag.
  See the available options below if you prefer fixing the root cause of the error:

  The following relabeling rule may be added to `relabel_configs` section in order to filter out pods with unneeded ports:

  ```yml
  - action: keep_if_equal
    source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_port, __meta_kubernetes_pod_container_port_number]
  ```

  The following relabeling rule may be added to `relabel_configs` section in order to filter out init container pods:

  ```yml
  - action: drop
    source_labels: [__meta_kubernetes_pod_container_init]
    regex: true
  ```

See also [troubleshooting docs](https://docs.victoriametrics.com/Troubleshooting.html).

## Kafka integration

[Enterprise version](https://docs.victoriametrics.com/enterprise.html) of `vmagent` can read and write metrics from / to Kafka:

* [Reading metrics from Kafka](#reading-metrics-from-kafka)
* [Writing metrics to Kafka](#writing-metrics-to-kafka)

The enterprise version of vmagent is available for evaluation at [releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) page
in `vmutils-...-enteprise.tar.gz` archives and in [docker images](https://hub.docker.com/r/victoriametrics/vmagent/tags) with tags containing `enterprise` suffix.

### Reading metrics from Kafka

[Enterprise version](https://docs.victoriametrics.com/enterprise.html) of `vmagent` can read metrics in various formats from Kafka messages.
These formats can be configured with `-kafka.consumer.topic.defaultFormat` or `-kafka.consumer.topic.format` command-line options. The following formats are supported:

* `promremotewrite` - [Prometheus remote_write](https://prometheus.io/docs/prometheus/latest/configuration/configuration/#remote_write).
  Messages in this format can be sent by vmagent - see [these docs](#writing-metrics-to-kafka).
* `influx` - [InfluxDB line protocol format](https://docs.influxdata.com/influxdb/v1.7/write_protocols/line_protocol_tutorial/).
* `prometheus` - [Prometheus text exposition format](https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md#text-based-format)
  and [OpenMetrics format](https://github.com/OpenObservability/OpenMetrics/blob/master/specification/OpenMetrics.md).
* `graphite` - [Graphite plaintext format](https://graphite.readthedocs.io/en/latest/feeding-carbon.html#the-plaintext-protocol).
* `jsonline` - [JSON line format](https://docs.victoriametrics.com/#how-to-import-data-in-json-line-format).

Every Kafka message may contain multiple lines in `influx`, `prometheus`, `graphite` and `jsonline` format delimited by `\n`.

`vmagent` consumes messages from Kafka topics specified by `-kafka.consumer.topic` command-line flag. Multiple topics can be specified
by passing multiple `-kafka.consumer.topic` command-line flags to `vmagent`.

`vmagent` consumes messages from Kafka brokers specified by `-kafka.consumer.topic.brokers` command-line flag.
Multiple brokers can be specified per each `-kafka.consumer.topic` by passing a list of brokers delimited by `;`.
For example, `-kafka.consumer.topic.brokers=host1:9092;host2:9092`.

The following command starts `vmagent`, which reads metrics in InfluxDB line protocol format from Kafka broker at `localhost:9092`
from the topic `metrics-by-telegraf` and sends them to remote storage at `http://localhost:8428/api/v1/write`:

```console
./bin/vmagent -remoteWrite.url=http://localhost:8428/api/v1/write \
       -kafka.consumer.topic.brokers=localhost:9092 \
       -kafka.consumer.topic.format=influx \
       -kafka.consumer.topic=metrics-by-telegraf \
       -kafka.consumer.topic.groupID=some-id
```

It is expected that [Telegraf](https://github.com/influxdata/telegraf) sends metrics to the `metrics-by-telegraf` topic with the following config:

```yaml
[[outputs.kafka]]
brokers = ["localhost:9092"]
topic = "influx"
data_format = "influx"
```

#### Command-line flags for Kafka consumer

These command-line flags are available only in [enterprise](https://docs.victoriametrics.com/enterprise.html) version of `vmagent`,
which can be downloaded for evaluation from [releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) page
(see `vmutils-...-enteprise.tar.gz` archives) and from [docker images](https://hub.docker.com/r/victoriametrics/vmagent/tags) with tags containing `enterprise` suffix.

```
  -kafka.consumer.topic array
        Kafka topic names for data consumption.
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.basicAuth.password array
        Optional basic auth password for -kafka.consumer.topic. Must be used in conjunction with any supported auth methods for kafka client, specified by flag -kafka.consumer.topic.options='security.protocol=SASL_SSL;sasl.mechanisms=PLAIN'
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.basicAuth.username array
        Optional basic auth username for -kafka.consumer.topic. Must be used in conjunction with any supported auth methods for kafka client, specified by flag -kafka.consumer.topic.options='security.protocol=SASL_SSL;sasl.mechanisms=PLAIN'
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.brokers array
        List of brokers to connect for given topic, e.g. -kafka.consumer.topic.broker=host-1:9092;host-2:9092
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.defaultFormat string
        Expected data format in the topic if -kafka.consumer.topic.format is skipped. (default "promremotewrite")
  -kafka.consumer.topic.format array
        data format for corresponding kafka topic. Valid formats: influx, prometheus, promremotewrite, graphite, jsonline
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.groupID array
        Defines group.id for topic
        Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.isGzipped array
        Enables gzip setting for topic messages payload. Only prometheus, jsonline and influx formats accept gzipped messages.
        Supports array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.options array
        Optional key=value;key1=value2 settings for topic consumer. See full configuration options at https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md.
        Supports an array of values separated by comma or specified via multiple flags.
```

### Writing metrics to Kafka

[Enterprise version](https://docs.victoriametrics.com/enterprise.html) of `vmagent` writes data to Kafka with `at-least-once`
semantics if `-remoteWrite.url` contains e.g. Kafka url. For example, if `vmagent` is started with `-remoteWrite.url=kafka://localhost:9092/?topic=prom-rw`,
then it would send Prometheus remote_write messages to Kafka bootstrap server at `localhost:9092` with the topic `prom-rw`.
These messages can be read later from Kafka by another `vmagent` - see [these docs](#reading-metrics-from-kafka) for details.

Additional Kafka options can be passed as query params to `-remoteWrite.url`. For instance, `kafka://localhost:9092/?topic=prom-rw&client.id=my-favorite-id`
sets `client.id` Kafka option to `my-favorite-id`. The full list of Kafka options is available [here](https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md).

#### Kafka broker authorization and authentication

Two types of auth are supported:

* sasl with username and password:

```console
./bin/vmagent -remoteWrite.url=kafka://localhost:9092/?topic=prom-rw&security.protocol=SASL_SSL&sasl.mechanisms=PLAIN -remoteWrite.basicAuth.username=user -remoteWrite.basicAuth.password=password
```

* tls certificates:

```console
./bin/vmagent -remoteWrite.url=kafka://localhost:9092/?topic=prom-rw&security.protocol=SSL -remoteWrite.tlsCAFile=/opt/ca.pem -remoteWrite.tlsCertFile=/opt/cert.pem -remoteWrite.tlsKeyFile=/opt/key.pem
```

## How to build from sources

We recommend using [official binary releases](https://github.com/VictoriaMetrics/VictoriaMetrics/releases) - `vmagent` is located in the `vmutils-...` archives.

It may be needed to build `vmagent` from source code when developing or testing new feature or bugfix.

### Development build

1. [Install Go](https://golang.org/doc/install). The minimum supported version is Go 1.19.
2. Run `make vmagent` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics).
   It builds the `vmagent` binary and puts it into the `bin` folder.

### Production build

1. [Install docker](https://docs.docker.com/install/).
2. Run `make vmagent-prod` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics).
   It builds `vmagent-prod` binary and puts it into the `bin` folder.

### Building docker images

Run `make package-vmagent`. It builds `victoriametrics/vmagent:<PKG_TAG>` docker image locally.
`<PKG_TAG>` is an auto-generated image tag, which depends on source code in [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics).
The `<PKG_TAG>` may be manually set via `PKG_TAG=foobar make package-vmagent`.

The base docker image is [alpine](https://hub.docker.com/_/alpine) but it is possible to use any other base image
by setting it via `<ROOT_IMAGE>` environment variable. For example, the following command builds the image on top of [scratch](https://hub.docker.com/_/scratch) image:

```console
ROOT_IMAGE=scratch make package-vmagent
```

### ARM build

ARM build may run on Raspberry Pi or on [energy-efficient ARM servers](https://blog.cloudflare.com/arm-takes-wing/).

### Development ARM build

1. [Install Go](https://golang.org/doc/install). The minimum supported version is Go 1.19.
2. Run `make vmagent-linux-arm` or `make vmagent-linux-arm64` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics)
   It builds `vmagent-linux-arm` or `vmagent-linux-arm64` binary respectively and puts it into the `bin` folder.

### Production ARM build

1. [Install docker](https://docs.docker.com/install/).
2. Run `make vmagent-linux-arm-prod` or `make vmagent-linux-arm64-prod` from the root folder of [the repository](https://github.com/VictoriaMetrics/VictoriaMetrics).
   It builds `vmagent-linux-arm-prod` or `vmagent-linux-arm64-prod` binary respectively and puts it into the `bin` folder.

## Profiling

`vmagent` provides handlers for collecting the following [Go profiles](https://blog.golang.org/profiling-go-programs):

* Memory profile can be collected with the following command (replace `0.0.0.0` with hostname if needed):

<div class="with-copy" markdown="1">

```console
curl http://0.0.0.0:8429/debug/pprof/heap > mem.pprof
```

</div>

* CPU profile can be collected with the following command (replace `0.0.0.0` with hostname if needed):

<div class="with-copy" markdown="1">

```console
curl http://0.0.0.0:8429/debug/pprof/profile > cpu.pprof
```

</div>

The command for collecting CPU profile waits for 30 seconds before returning.

The collected profiles may be analyzed with [go tool pprof](https://github.com/google/pprof).

It is safe sharing the collected profiles from security point of view, since they do not contain sensitive information.

## Advanced usage

`vmagent` can be fine-tuned with various command-line flags. Run `./vmagent -help` in order to see the full list of these flags with their desciptions and default values:

```
./vmagent -help

vmagent collects metrics data via popular data ingestion protocols and routes them to VictoriaMetrics.

See the docs at https://docs.victoriametrics.com/vmagent.html .

  -cacheExpireDuration duration
     Items are removed from in-memory caches after they aren't accessed for this duration. Lower values may reduce memory usage at the cost of higher CPU usage. See also -prevCacheRemovalPercent (default 30m0s)
  -configAuthKey string
     Authorization key for accessing /config page. It must be passed via authKey query arg
  -csvTrimTimestamp duration
     Trim timestamps when importing csv data to this duration. Minimum practical duration is 1ms. Higher duration (i.e. 1s) may be used for reducing disk space usage for timestamp data (default 1ms)
  -datadog.maxInsertRequestSize size
     The maximum size in bytes of a single DataDog POST request to /api/v1/series
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 67108864)
  -datadog.sanitizeMetricName
     Sanitize metric names for the ingested DataDog data to comply with DataDog behaviour described at https://docs.datadoghq.com/metrics/custom_metrics/#naming-custom-metrics (default true)
  -denyQueryTracing
     Whether to disable the ability to trace queries. See https://docs.victoriametrics.com/#query-tracing
  -dryRun
     Whether to check only config files without running vmagent. The following files are checked: -promscrape.config, -remoteWrite.relabelConfig, -remoteWrite.urlRelabelConfig . Unknown config entries aren't allowed in -promscrape.config by default. This can be changed by passing -promscrape.config.strictParse=false command-line flag
  -enableTCP6
     Whether to enable IPv6 for listening and dialing. By default only IPv4 TCP and UDP is used
  -envflag.enable
     Whether to enable reading flags from environment variables additionally to command line. Command line flag values have priority over values from environment vars. Flags are read only from command line if this flag isn't set. See https://docs.victoriametrics.com/#environment-variables for more details
  -envflag.prefix string
     Prefix for environment variables if -envflag.enable is set
  -eula
     By specifying this flag, you confirm that you have an enterprise license and accept the EULA https://victoriametrics.com/assets/VM_EULA.pdf . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
  -flagsAuthKey string
     Auth key for /flags endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -fs.disableMmap
     Whether to use pread() instead of mmap() for reading data files. By default mmap() is used for 64-bit arches and pread() is used for 32-bit arches, since they cannot read data files bigger than 2^32 bytes in memory. mmap() is usually faster for reading small data chunks than pread()
  -graphiteListenAddr string
     TCP and UDP address to listen for Graphite plaintext data. Usually :2003 must be set. Doesn't work if empty
  -graphiteTrimTimestamp duration
     Trim timestamps for Graphite data to this duration. Minimum practical duration is 1s. Higher duration (i.e. 1m) may be used for reducing disk space usage for timestamp data (default 1s)
  -http.connTimeout duration
     Incoming http connections are closed after the configured timeout. This may help to spread the incoming load among a cluster of services behind a load balancer. Please note that the real timeout may be bigger by up to 10% as a protection against the thundering herd problem (default 2m0s)
  -http.disableResponseCompression
     Disable compression of HTTP responses to save CPU resources. By default compression is enabled to save network bandwidth
  -http.idleConnTimeout duration
     Timeout for incoming idle http connections (default 1m0s)
  -http.maxGracefulShutdownDuration duration
     The maximum duration for a graceful shutdown of the HTTP server. A highly loaded server may require increased value for a graceful shutdown (default 7s)
  -http.pathPrefix string
     An optional prefix to add to all the paths handled by http server. For example, if '-http.pathPrefix=/foo/bar' is set, then all the http requests will be handled on '/foo/bar/*' paths. This may be useful for proxied requests. See https://www.robustperception.io/using-external-urls-and-proxies-with-prometheus
  -http.shutdownDelay duration
     Optional delay before http server shutdown. During this delay, the server returns non-OK responses from /health page, so load balancers can route new requests to other servers
  -httpAuth.password string
     Password for HTTP Basic Auth. The authentication is disabled if -httpAuth.username is empty
  -httpAuth.username string
     Username for HTTP Basic Auth. The authentication is disabled if empty. See also -httpAuth.password
  -httpListenAddr string
     TCP address to listen for http connections. Set this flag to empty value in order to disable listening on any port. This mode may be useful for running multiple vmagent instances on the same server. Note that /targets and /metrics pages aren't available if -httpListenAddr='' (default ":8429")
  -import.maxLineLen size
     The maximum length in bytes of a single line accepted by /api/v1/import; the line length can be limited with 'max_rows_per_line' query arg passed to /api/v1/export
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 104857600)
  -influx.databaseNames array
     Comma-separated list of database names to return from /query and /influx/query API. This can be needed for accepting data from Telegraf plugins such as https://github.com/fangli/fluent-plugin-influxdb
     Supports an array of values separated by comma or specified via multiple flags.
  -influx.maxLineSize size
     The maximum size in bytes for a single InfluxDB line during parsing
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 262144)
  -influxDBLabel string
     Default label for the DB name sent over '?db={db_name}' query parameter (default "db")
  -influxListenAddr string
     TCP and UDP address to listen for InfluxDB line protocol data. Usually :8089 must be set. Doesn't work if empty. This flag isn't needed when ingesting data over HTTP - just send it to http://<vmagent>:8429/write
  -influxMeasurementFieldSeparator string
     Separator for '{measurement}{separator}{field_name}' metric name when inserted via InfluxDB line protocol (default "_")
  -influxSkipMeasurement
     Uses '{field_name}' as a metric name while ignoring '{measurement}' and '-influxMeasurementFieldSeparator'
  -influxSkipSingleField
     Uses '{measurement}' instead of '{measurement}{separator}{field_name}' for metic name if InfluxDB line contains only a single field
  -influxTrimTimestamp duration
     Trim timestamps for InfluxDB line protocol data to this duration. Minimum practical duration is 1ms. Higher duration (i.e. 1s) may be used for reducing disk space usage for timestamp data (default 1ms)
  -insert.maxQueueDuration duration
     The maximum duration for waiting in the queue for insert requests due to -maxConcurrentInserts (default 1m0s)
  -kafka.consumer.topic array
     Kafka topic names for data consumption. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.basicAuth.password array
     Optional basic auth password for -kafka.consumer.topic. Must be used in conjunction with any supported auth methods for kafka client, specified by flag -kafka.consumer.topic.options='security.protocol=SASL_SSL;sasl.mechanisms=PLAIN' . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.basicAuth.username array
     Optional basic auth username for -kafka.consumer.topic. Must be used in conjunction with any supported auth methods for kafka client, specified by flag -kafka.consumer.topic.options='security.protocol=SASL_SSL;sasl.mechanisms=PLAIN' . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.brokers array
     List of brokers to connect for given topic, e.g. -kafka.consumer.topic.broker=host-1:9092;host-2:9092 . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.defaultFormat string
     Expected data format in the topic if -kafka.consumer.topic.format is skipped. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html (default "promremotewrite")
  -kafka.consumer.topic.format array
     data format for corresponding kafka topic. Valid formats: influx, prometheus, promremotewrite, graphite, jsonline . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.groupID array
     Defines group.id for topic. This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.isGzipped array
     Enables gzip setting for topic messages payload. Only prometheus, jsonline and influx formats accept gzipped messages.This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports array of values separated by comma or specified via multiple flags.
  -kafka.consumer.topic.options array
     Optional key=value;key1=value2 settings for topic consumer. See full configuration options at https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
     Supports an array of values separated by comma or specified via multiple flags.
  -loggerDisableTimestamps
     Whether to disable writing timestamps in logs
  -loggerErrorsPerSecondLimit int
     Per-second limit on the number of ERROR messages. If more than the given number of errors are emitted per second, the remaining errors are suppressed. Zero values disable the rate limit
  -loggerFormat string
     Format for logs. Possible values: default, json (default "default")
  -loggerLevel string
     Minimum level of errors to log. Possible values: INFO, WARN, ERROR, FATAL, PANIC (default "INFO")
  -loggerOutput string
     Output for the logs. Supported values: stderr, stdout (default "stderr")
  -loggerTimezone string
     Timezone to use for timestamps in logs. Timezone must be a valid IANA Time Zone. For example: America/New_York, Europe/Berlin, Etc/GMT+3 or Local (default "UTC")
  -loggerWarnsPerSecondLimit int
     Per-second limit on the number of WARN messages. If more than the given number of warns are emitted per second, then the remaining warns are suppressed. Zero values disable the rate limit
  -maxConcurrentInserts int
     The maximum number of concurrent inserts. Default value should work for most cases, since it minimizes the overhead for concurrent inserts. This option is tigthly coupled with -insert.maxQueueDuration (default 16)
  -maxInsertRequestSize size
     The maximum size in bytes of a single Prometheus remote_write API request
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 33554432)
  -memory.allowedBytes size
     Allowed size of system memory VictoriaMetrics caches may occupy. This option overrides -memory.allowedPercent if set to a non-zero value. Too low a value may increase the cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache resulting in higher disk IO usage
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 0)
  -memory.allowedPercent float
     Allowed percent of system memory VictoriaMetrics caches may occupy. See also -memory.allowedBytes. Too low a value may increase cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache which will result in higher disk IO usage (default 60)
  -metricsAuthKey string
     Auth key for /metrics endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -opentsdbHTTPListenAddr string
     TCP address to listen for OpentTSDB HTTP put requests. Usually :4242 must be set. Doesn't work if empty
  -opentsdbListenAddr string
     TCP and UDP address to listen for OpentTSDB metrics. Telnet put messages and HTTP /api/put messages are simultaneously served on TCP port. Usually :4242 must be set. Doesn't work if empty
  -opentsdbTrimTimestamp duration
     Trim timestamps for OpenTSDB 'telnet put' data to this duration. Minimum practical duration is 1s. Higher duration (i.e. 1m) may be used for reducing disk space usage for timestamp data (default 1s)
  -opentsdbhttp.maxInsertRequestSize size
     The maximum size of OpenTSDB HTTP put request
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 33554432)
  -opentsdbhttpTrimTimestamp duration
     Trim timestamps for OpenTSDB HTTP data to this duration. Minimum practical duration is 1ms. Higher duration (i.e. 1s) may be used for reducing disk space usage for timestamp data (default 1ms)
  -pprofAuthKey string
     Auth key for /debug/pprof/* endpoints. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -prevCacheRemovalPercent float
     Items in the previous caches are removed when the percent of requests it serves becomes lower than this value. Higher values reduce memory usage at the cost of higher CPU usage. See also -cacheExpireDuration (default 0.1)
  -promscrape.azureSDCheckInterval duration
     Interval for checking for changes in Azure. This works only if azure_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#azure_sd_configs for details (default 1m0s)
  -promscrape.cluster.memberNum string
     The number of number in the cluster of scrapers. It must be an unique value in the range 0 ... promscrape.cluster.membersCount-1 across scrapers in the cluster. Can be specified as pod name of Kubernetes StatefulSet - pod-name-Num, where Num is a numeric part of pod name (default "0")
  -promscrape.cluster.membersCount int
     The number of members in a cluster of scrapers. Each member must have an unique -promscrape.cluster.memberNum in the range 0 ... promscrape.cluster.membersCount-1 . Each member then scrapes roughly 1/N of all the targets. By default cluster scraping is disabled, i.e. a single scraper scrapes all the targets
  -promscrape.cluster.name string
     Optional name of the cluster. If multiple vmagent clusters scrape the same targets, then each cluster must have unique name in order to properly de-duplicate samples received from these clusters. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2679
  -promscrape.cluster.replicationFactor int
     The number of members in the cluster, which scrape the same targets. If the replication factor is greater than 1, then the deduplication must be enabled at remote storage side. See https://docs.victoriametrics.com/#deduplication (default 1)
  -promscrape.config string
     Optional path to Prometheus config file with 'scrape_configs' section containing targets to scrape. The path can point to local file and to http url. See https://docs.victoriametrics.com/#how-to-scrape-prometheus-exporters-such-as-node-exporter for details
  -promscrape.config.dryRun
     Checks -promscrape.config file for errors and unsupported fields and then exits. Returns non-zero exit code on parsing errors and emits these errors to stderr. See also -promscrape.config.strictParse command-line flag. Pass -loggerLevel=ERROR if you don't need to see info messages in the output.
  -promscrape.config.strictParse
     Whether to deny unsupported fields in -promscrape.config . Set to false in order to silently skip unsupported fields (default true)
  -promscrape.configCheckInterval duration
     Interval for checking for changes in '-promscrape.config' file. By default the checking is disabled. Send SIGHUP signal in order to force config check for changes
  -promscrape.consul.waitTime duration
     Wait time used by Consul service discovery. Default value is used if not set
  -promscrape.consulSDCheckInterval duration
     Interval for checking for changes in Consul. This works only if consul_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#consul_sd_configs for details (default 30s)
  -promscrape.digitaloceanSDCheckInterval duration
     Interval for checking for changes in digital ocean. This works only if digitalocean_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#digitalocean_sd_configs for details (default 1m0s)
  -promscrape.disableCompression
     Whether to disable sending 'Accept-Encoding: gzip' request headers to all the scrape targets. This may reduce CPU usage on scrape targets at the cost of higher network bandwidth utilization. It is possible to set 'disable_compression: true' individually per each 'scrape_config' section in '-promscrape.config' for fine grained control
  -promscrape.disableKeepAlive
     Whether to disable HTTP keep-alive connections when scraping all the targets. This may be useful when targets has no support for HTTP keep-alive connection. It is possible to set 'disable_keepalive: true' individually per each 'scrape_config' section in '-promscrape.config' for fine grained control. Note that disabling HTTP keep-alive may increase load on both vmagent and scrape targets
  -promscrape.discovery.concurrency int
     The maximum number of concurrent requests to Prometheus autodiscovery API (Consul, Kubernetes, etc.) (default 100)
  -promscrape.discovery.concurrentWaitTime duration
     The maximum duration for waiting to perform API requests if more than -promscrape.discovery.concurrency requests are simultaneously performed (default 1m0s)
  -promscrape.dnsSDCheckInterval duration
     Interval for checking for changes in dns. This works only if dns_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#dns_sd_configs for details (default 30s)
  -promscrape.dockerSDCheckInterval duration
     Interval for checking for changes in docker. This works only if docker_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#docker_sd_configs for details (default 30s)
  -promscrape.dockerswarmSDCheckInterval duration
     Interval for checking for changes in dockerswarm. This works only if dockerswarm_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#dockerswarm_sd_configs for details (default 30s)
  -promscrape.dropOriginalLabels
     Whether to drop original labels for scrape targets at /targets and /api/v1/targets pages. This may be needed for reducing memory usage when original labels for big number of scrape targets occupy big amounts of memory. Note that this reduces debuggability for improper per-target relabeling configs
  -promscrape.ec2SDCheckInterval duration
     Interval for checking for changes in ec2. This works only if ec2_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#ec2_sd_configs for details (default 1m0s)
  -promscrape.eurekaSDCheckInterval duration
     Interval for checking for changes in eureka. This works only if eureka_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#eureka_sd_configs for details (default 30s)
  -promscrape.fileSDCheckInterval duration
     Interval for checking for changes in 'file_sd_config'. See https://docs.victoriametrics.com/sd_configs.html#file_sd_configs for details (default 1m0s)
  -promscrape.gceSDCheckInterval duration
     Interval for checking for changes in gce. This works only if gce_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#gce_sd_configs for details (default 1m0s)
  -promscrape.httpSDCheckInterval duration
     Interval for checking for changes in http endpoint service discovery. This works only if http_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#http_sd_configs for details (default 1m0s)
  -promscrape.kubernetes.apiServerTimeout duration
     How frequently to reload the full state from Kubernetes API server (default 30m0s)
  -promscrape.kubernetesSDCheckInterval duration
     Interval for checking for changes in Kubernetes API server. This works only if kubernetes_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#kubernetes_sd_configs for details (default 30s)
  -promscrape.maxDroppedTargets int
     The maximum number of droppedTargets to show at /api/v1/targets page. Increase this value if your setup drops more scrape targets during relabeling and you need investigating labels for all the dropped targets. Note that the increased number of tracked dropped targets may result in increased memory usage (default 1000)
  -promscrape.maxResponseHeadersSize size
     The maximum size of http response headers from Prometheus scrape targets
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 4096)
  -promscrape.maxScrapeSize size
     The maximum size of scrape response in bytes to process from Prometheus targets. Bigger responses are rejected
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 16777216)
  -promscrape.minResponseSizeForStreamParse size
     The minimum target response size for automatic switching to stream parsing mode, which can reduce memory usage. See https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 1000000)
  -promscrape.noStaleMarkers
     Whether to disable sending Prometheus stale markers for metrics when scrape target disappears. This option may reduce memory usage if stale markers aren't needed for your setup. This option also disables populating the scrape_series_added metric. See https://prometheus.io/docs/concepts/jobs_instances/#automatically-generated-labels-and-time-series
  -promscrape.openstackSDCheckInterval duration
     Interval for checking for changes in openstack API server. This works only if openstack_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#openstack_sd_configs for details (default 30s)
  -promscrape.seriesLimitPerTarget int
     Optional limit on the number of unique time series a single scrape target can expose. See https://docs.victoriametrics.com/vmagent.html#cardinality-limiter for more info
  -promscrape.streamParse
     Whether to enable stream parsing for metrics obtained from scrape targets. This may be useful for reducing memory usage when millions of metrics are exposed per each scrape target. It is posible to set 'stream_parse: true' individually per each 'scrape_config' section in '-promscrape.config' for fine grained control
  -promscrape.suppressDuplicateScrapeTargetErrors
     Whether to suppress 'duplicate scrape target' errors; see https://docs.victoriametrics.com/vmagent.html#troubleshooting for details
  -promscrape.suppressScrapeErrors
     Whether to suppress scrape errors logging. The last error for each target is always available at '/targets' page even if scrape errors logging is suppressed. See also -promscrape.suppressScrapeErrorsDelay
  -promscrape.suppressScrapeErrorsDelay duration
     The delay for suppressing repeated scrape errors logging per each scrape targets. This may be used for reducing the number of log lines related to scrape errors. See also -promscrape.suppressScrapeErrors
  -promscrape.yandexcloudSDCheckInterval duration
     Interval for checking for changes in Yandex Cloud API. This works only if yandexcloud_sd_configs is configured in '-promscrape.config' file. See https://docs.victoriametrics.com/sd_configs.html#yandexcloud_sd_configs for details (default 30s)
  -pushmetrics.extraLabel array
     Optional labels to add to metrics pushed to -pushmetrics.url . For example, -pushmetrics.extraLabel='instance="foo"' adds instance="foo" label to all the metrics pushed to -pushmetrics.url
     Supports an array of values separated by comma or specified via multiple flags.
  -pushmetrics.interval duration
     Interval for pushing metrics to -pushmetrics.url (default 10s)
  -pushmetrics.url array
     Optional URL to push metrics exposed at /metrics page. See https://docs.victoriametrics.com/#push-metrics . By default metrics exposed at /metrics page aren't pushed to any remote storage
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.accessKey array
     Optional AWS AccessKey to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.ec2Endpoint array
     Optional AWS EC2 API endpoint to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.region array
     Optional AWS region to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.roleARN array
     Optional AWS roleARN to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.secretKey array
     Optional AWS SecretKey to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.service array
     Optional AWS Service to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set. Defaults to "aps"
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.stsEndpoint array
     Optional AWS STS API endpoint to use for the corresponding -remoteWrite.url if -remoteWrite.aws.useSigv4 is set
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.aws.useSigv4 array
     Enables SigV4 request signing for the corresponding -remoteWrite.url. It is expected that other -remoteWrite.aws.* command-line flags are set if sigv4 request signing is enabled
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.basicAuth.password array
     Optional basic auth password to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.basicAuth.passwordFile array
     Optional path to basic auth password to use for the corresponding -remoteWrite.url. The file is re-read every second
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.basicAuth.username array
     Optional basic auth username to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.bearerToken array
     Optional bearer auth token to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.bearerTokenFile array
     Optional path to bearer token file to use for the corresponding -remoteWrite.url. The token is re-read from the file every second
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.flushInterval duration
     Interval for flushing the data to remote storage. This option takes effect only when less than 10K data points per second are pushed to -remoteWrite.url (default 1s)
  -remoteWrite.headers array
     Optional HTTP headers to send with each request to the corresponding -remoteWrite.url. For example, -remoteWrite.headers='My-Auth:foobar' would send 'My-Auth: foobar' HTTP header with every request to the corresponding -remoteWrite.url. Multiple headers must be delimited by '^^': -remoteWrite.headers='header1:value1^^header2:value2'
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.label array
     Optional label in the form 'name=value' to add to all the metrics before sending them to -remoteWrite.url. Pass multiple -remoteWrite.label flags in order to add multiple labels to metrics before sending them to remote storage
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.maxBlockSize size
     The maximum block size to send to remote storage. Bigger blocks may improve performance at the cost of the increased memory usage. See also -remoteWrite.maxRowsPerBlock
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB (default 8388608)
  -remoteWrite.maxDailySeries int
     The maximum number of unique series vmagent can send to remote storage systems during the last 24 hours. Excess series are logged and dropped. This can be useful for limiting series churn rate. See https://docs.victoriametrics.com/vmagent.html#cardinality-limiter
  -remoteWrite.maxDiskUsagePerURL array
     The maximum file-based buffer size in bytes at -remoteWrite.tmpDataPath for each -remoteWrite.url. When buffer size reaches the configured maximum, then old data is dropped when adding new data to the buffer. Buffered data is stored in ~500MB chunks, so the minimum practical value for this flag is 500MB. Disk usage is unlimited if the value is set to 0
     Supports the following optional suffixes for size values: KB, MB, GB, KiB, MiB, GiB.
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.maxHourlySeries int
     The maximum number of unique series vmagent can send to remote storage systems during the last hour. Excess series are logged and dropped. This can be useful for limiting series cardinality. See https://docs.victoriametrics.com/vmagent.html#cardinality-limiter
  -remoteWrite.maxRowsPerBlock int
     The maximum number of samples to send in each block to remote storage. Higher number may improve performance at the cost of the increased memory usage. See also -remoteWrite.maxBlockSize (default 10000)
  -remoteWrite.multitenantURL array
     Base path for multitenant remote storage URL to write data to. See https://docs.victoriametrics.com/vmagent.html#multitenancy for details. Example url: http://<vminsert>:8480 . Pass multiple -remoteWrite.multitenantURL flags in order to replicate data to multiple remote storage systems. See also -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.oauth2.clientID array
     Optional OAuth2 clientID to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.oauth2.clientSecret array
     Optional OAuth2 clientSecret to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.oauth2.clientSecretFile array
     Optional OAuth2 clientSecretFile to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.oauth2.scopes array
     Optional OAuth2 scopes to use for the corresponding -remoteWrite.url. Scopes must be delimited by ';'
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.oauth2.tokenUrl array
     Optional OAuth2 tokenURL to use for the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.proxyURL array
     Optional proxy URL for writing data to the corresponding -remoteWrite.url. Supported proxies: http, https, socks5. Example: -remoteWrite.proxyURL=socks5://proxy:1234
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.queues int
     The number of concurrent queues to each -remoteWrite.url. Set more queues if default number of queues isn't enough for sending high volume of collected data to remote storage. Default value is 2 * numberOfAvailableCPUs (default 8)
  -remoteWrite.rateLimit array
     Optional rate limit in bytes per second for data sent to the corresponding -remoteWrite.url. By default the rate limit is disabled. It can be useful for limiting load on remote storage when big amounts of buffered data is sent after temporary unavailability of the remote storage
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.relabelConfig string
     Optional path to file with relabel_config entries. The path can point either to local file or to http url. These entries are applied to all the metrics before sending them to -remoteWrite.url. See https://docs.victoriametrics.com/vmagent.html#relabeling for details
  -remoteWrite.roundDigits array
     Round metric values to this number of decimal digits after the point before writing them to remote storage. Examples: -remoteWrite.roundDigits=2 would round 1.236 to 1.24, while -remoteWrite.roundDigits=-1 would round 126.78 to 130. By default digits rounding is disabled. Set it to 100 for disabling it for a particular remote storage. This option may be used for improving data compression for the stored metrics
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.sendTimeout array
     Timeout for sending a single block of data to the corresponding -remoteWrite.url
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.showURL
     Whether to show -remoteWrite.url in the exported metrics. It is hidden by default, since it can contain sensitive info such as auth key
  -remoteWrite.significantFigures array
     The number of significant figures to leave in metric values before writing them to remote storage. See https://en.wikipedia.org/wiki/Significant_figures . Zero value saves all the significant figures. This option may be used for improving data compression for the stored metrics. See also -remoteWrite.roundDigits
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.tlsCAFile array
     Optional path to TLS CA file to use for verifying connections to the corresponding -remoteWrite.url. By default system CA is used
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.tlsCertFile array
     Optional path to client-side TLS certificate file to use when connecting to the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.tlsInsecureSkipVerify array
     Whether to skip tls verification when connecting to the corresponding -remoteWrite.url
     Supports array of values separated by comma or specified via multiple flags.
  -remoteWrite.tlsKeyFile array
     Optional path to client-side TLS certificate key to use when connecting to the corresponding -remoteWrite.url
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.tlsServerName array
     Optional TLS server name to use for connections to the corresponding -remoteWrite.url. By default the server name from -remoteWrite.url is used
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.tmpDataPath string
     Path to directory where temporary data for remote write component is stored. See also -remoteWrite.maxDiskUsagePerURL (default "vmagent-remotewrite-data")
  -remoteWrite.url array
     Remote storage URL to write data to. It must support Prometheus remote_write API. It is recommended using VictoriaMetrics as remote storage. Example url: http://<victoriametrics-host>:8428/api/v1/write . Pass multiple -remoteWrite.url flags in order to replicate data to multiple remote storage systems. See also -remoteWrite.multitenantURL
     Supports an array of values separated by comma or specified via multiple flags.
  -remoteWrite.urlRelabelConfig array
     Optional path to relabel config for the corresponding -remoteWrite.url. The path can point either to local file or to http url
     Supports an array of values separated by comma or specified via multiple flags.
  -sortLabels
     Whether to sort labels for incoming samples before writing them to all the configured remote storage systems. This may be needed for reducing memory usage at remote storage when the order of labels in incoming samples is random. For example, if m{k1="v1",k2="v2"} may be sent as m{k2="v2",k1="v1"}Enabled sorting for labels can slow down ingestion performance a bit
  -tls
     Whether to enable TLS for incoming HTTP requests at -httpListenAddr (aka https). -tlsCertFile and -tlsKeyFile must be set if -tls is set
  -tlsCertFile string
     Path to file with TLS certificate if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated
  -tlsCipherSuites array
     Optional list of TLS cipher suites for incoming requests over HTTPS if -tls is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants
     Supports an array of values separated by comma or specified via multiple flags.
  -tlsKeyFile string
     Path to file with TLS key if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated
  -tlsMinVersion string
     Optional minimum TLS version to use for incoming requests over HTTPS if -tls is set. Supported values: TLS10, TLS11, TLS12, TLS13
  -usePromCompatibleNaming
     Whether to replace characters unsupported by Prometheus with underscores in the ingested metric names and label names. For example, foo.bar{a.b='c'} is transformed into foo_bar{a_b='c'} during data ingestion if this flag is set. See https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels
  -version
     Show VictoriaMetrics version
```
