Flatstore Module

Jan Janak

   FhG FOKUS

Edited by

Jan Janak

   Copyright © 2004, 2005 FhG FOKUS
   Revision History
   Revision $Revision: 4630 $ $Date: 2008-08-06 12:08:33 +0200
                              (Mi, 06 Aug 2008) $
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview

              1.1.1. Rotating Log Files

        1.2. Dependencies

              1.2.1. Kamailio Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. flush (integer)

        1.4. Exported Functions
        1.5. Exported MI Functions

              1.5.1. flat_rotate

   2. Developer Guide

   List of Examples

   1.1. Set "flush" parameter

Chapter 1. Admin Guide

1.1. Overview

   Flatstore is one of so-called Kamailio database modules. It
   does not export any functions executable from the configuration
   scripts, but it exports a subset of functions from the database
   API and thus other module can use it instead of, for example,
   mysql module.

   The module does not export all functions of the database API,
   it supports only one function, insert. The module is limited
   but very fast. It is especially suitable for storing accounting
   information on sites with extremely high traffic. If MySQL is
   too slow or if you get a huge amount of accounting data then
   you can consider using this module. Note that the acc module is
   the only module that was tested with flastore.

   The format of the files produced by this module is plain text.
   Each line consists of several fields, fields are separated by |
   character. New information is always appended at the end of the
   file, searching, deleting and updating of existing data is not
   supported by the module.

   The acc module can be configured to use flatstore module as
   database backend using the db_url_parameter:
modparam("acc", "db_url", "flatstore:/var/log/acc")

   This configuration options tells acc module that it should use
   the flatstore module and the flatstore module should create all
   files in /var/log/acc directory. The directory must exist and
   Kamailio processes must have permissions to create files in
   that directory.

   Name of files in that directory will follow the following
   pattern:
<table_name>_<process_name>.log

   For example, entries writen by Kamailio process 8 into acc
   table would be written in file acc_8.log. For each table there
   will be several files, one file for every Kamailio process that
   wrote some data into that table. The main reason why there are
   several files for each table is that it is much faster to have
   one file per process, because it does not require any locking
   and thus Kamailio processes will not block each other. To get
   the complete data for a table you can simply concatenate the
   contents of files with the same table name but different
   process id.

1.1.1. Rotating Log Files

   There is a new Kamailio MI (management interface) command
   called flat_rotate. When Kamailio receives the command then it
   will close and reopen all files used by flatstore module. The
   rotation itself has to be done by another application (such as
   logrotate). Follow these steps to rotate files generated by
   flatstore module:
     * Rename the files that you want to rotate:
cd /var/log/acc
mv acc_1.log acc_1.log.20050605
mv acc_2.log acc_2.log.20050605
mv acc_4.log acc_3.log.20050605
...

       Note that at this point Kamailio will still be writing all
       data into the renamed files.
     * Send Kamailio the MI command to close and reopen the
       renamed files. For example, using FIFO:
kamctl fifo flat_rotate

       This will force Kamailio to close the renamed files and
       open new ones with original names, such as acc_1.log. New
       files will be open at the point when Kamailio has some data
       to write. It is normal that the files will be not created
       immediately if there is no traffic on the proxy server.
     * Move the renamed files somewhere else and process them.

1.2. Dependencies

1.2.1. Kamailio Modules

   The following modules must be loaded before this module:
     * No dependencies on other Kamailio modules.

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running Kamailio with this module loaded:
     * None.

1.3. Exported Parameters

1.3.1. flush (integer)

   Enable or disable flushing after each write.

   Default value is 1.

   Example 1.1. Set "flush" parameter
...
modparam("db_flatstore", "flush", 0)
...

1.4. Exported Functions

   There are no function exported to routing script.

1.5. Exported MI Functions

1.5.1.  flat_rotate

   It changes the name of the files where it is written.

   Name: flat_rotate

   Parameters: none

   MI FIFO Command Format:
                :flat_rotate:_reply_fifo_file_
                _empty_line_

Chapter 2. Developer Guide

   The module implements the DB API.
