cachedb_redis Module

Vladut-Stefan Paiu

   OpenSIPS Solutions

Edited by

Vladut-Stefan Paiu

   Copyright © 2011 www.opensips-solutions.com
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Advantages
        1.3. Limitations
        1.4. Dependencies

              1.4.1. OpenSIPS Modules
              1.4.2. External Libraries or Applications

        1.5. Exported Parameters

              1.5.1. cachedb_url (string)
              1.5.2. Exported Functions

   List of Examples

   1.1. Set cachedb_url parameter
   1.2. Use Redis servers

Chapter 1. Admin Guide

1.1. Overview

   This module is an implementation of a cache system designed to
   work with a Redis server. It uses hiredis client library to
   connect to either a single Redis server instance, or to a Redis
   Server inside a Redis Cluster. It uses the Key-Value interface
   exported from the core.

1.2. Advantages

     * memory costs are no longer on the server
     * many servers can be used inside a cluster, so the memory is
       virtually unlimited
     * the cache is 100% persistent. A restart of OpenSIPS server
       will not affect the DB. The Redis DB is also persistent so
       it can also be restarted without loss of information.
     * redis is an open-source project so it can be used to
       exchange data with various other applicationsr
     * By creating a Redis Cluster, multiple OpenSIPS instances
       can easily share key-value information

1.3. Limitations

     * keys (in key:value pairs) may not contain spaces or control
       characters

1.4. Dependencies

1.4.1. OpenSIPS Modules

   None.

1.4.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * hiredis:
       hiredis can be downloaded from:
       https://github.com/antirez/hiredis . Download the archive,
       extract sources, run make,sudo make install.

1.5. Exported Parameters

1.5.1. cachedb_url (string)

   The urls of the server groups that OpenSIPS will connect to in
   order to use the from script cache_store,cache_fetch, etc
   operations. It can be set more than one time. The prefix part
   of the URL will be the identifier that will be used from the
   script.

   Example 1.1. Set cachedb_url parameter
...
modparam("cachedb_redis", "cachedb_url","redis:group1://localhost:6379/"
);
modparam("cachedb_redis", "cachedb_url","redis:cluster1://random_url:888
8/");
...

   Example 1.2. Use Redis servers
...
cache_store("redis:group1","key","$ru value");
cache_fetch("redis:cluster1","key",$avp(10));
cache_remove("redis:cluster1","key");
...

1.5.2. Exported Functions

   The module does not export functions to be used in
   configuration script.