1. Flatstore Module

Jan Janak

   FhG FOKUS
   <jan@iptel.org>

   Copyright © 2004, 2005 FhG FOKUS
   Revision History
   Revision $Revision: 1.1.4.1 $ $Date: 2008/06/11 13:14:48 $
     __________________________________________________________________

   1.1. Overview

        1.1.1. Rotating Log Files

   1.2. Parameters

        1.2.1. flush (integer)

1.1. Overview

   Flatstore is one of so-called SER 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 SER 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 SER 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 SER 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 SER 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 SER FIFO interface command called flat_rotate. When SER
   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 SER will still be writing all data into the
       renamed files.
     * Send SER the fifo command to close and reopen the renamed files:
serctl fifo flat_rotate
       This will force SER 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 SER 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. Parameters

   Revision History
   Revision $Revision: 1.1.4.1 $ $Date: 2008/06/11 13:14:48 $

1.2.1. flush (integer)

   Enable or disable flushing after each write.

   Default value is 1.
