cachedb_redis Module

List of Tables

2.1. Top contributors by DevScore⁽¹⁾, authored commits⁽²⁾ and lines added/removed⁽³⁾
2.2. Most recently active contributors⁽¹⁾ to this module

List of Examples

1.1. Set cachedb_url parameter
1.2. Use Redis servers
1.3. Set connect_timeout parameter
1.4. Set connect_timeout parameter
1.5. Set the shutdown_on_error parameter
1.6. Set the use_tls parameter
1.7. Redis Raw Query Examples

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 applications
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

The following modules must be loaded before this module:

If a use_tls is defined, the tls_mgm module will need to be loaded as well.

1.4.2. External Libraries or Applications

The following libraries or applications must be installed before running OpenSIPS with this module loaded:

hiredis:
On the latest Debian based distributions, hiredis can be installed by running 'apt-get install libhiredis-dev' Alternatively, if hiredis is not available on your OS repos, hiredis can be downloaded from: https://github.com/antirez/hiredis . Download the archive, extract sources, run make,sudo make install.
If TLS connections are enabled via the use_tls modparam, hiredis needs to be compiled with TLS support.

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, from script, the cache_store(), cache_fetch(), etc. operations. It may be set more than once. The prefix part of the URL will be the identifier that will be used from the script.

Example 1.1. Set cachedb_url parameter

...
# single-instance URLs (Redis Server or Redis Cluster)
modparam("cachedb_redis", "cachedb_url", "redis:group1://localhost:6379/")
modparam("cachedb_redis", "cachedb_url", "redis:cluster1://random_url:8888/")

# multi-instance URL (will perform circular failover on each query)
modparam("cachedb_redis", "cachedb_url",
	"redis:ha://localhost,host_a:6380,host_b:6381,host_c/")
...

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. `connect_timeout` (integer)

This parameter specifies how many milliseconds OpenSIPS should wait for connecting to a Redis node.

Default value is “5000 ms”.

Example 1.3. Set connect_timeout parameter

...
# wait 1 seconds for Redis to connect
modparam("cachedb_redis", "connect_timeout",1000)
...

1.5.3. `query_timeout` (integer)

This parameter specifies how many milliseconds OpenSIPS should wait for a query response from a Redis node.

Default value is “5000 ms”.

Example 1.4. Set connect_timeout parameter

...
# wait 1 seconds for Redis queries
modparam("cachedb_redis", "query_timeout",1000)
...

1.5.4. `shutdown_on_error` (integer)

By setting this parameter to 1, OpenSIPS will abort startup if the initial connection to Redis is not possible. Runtime reconnect behavior is unaffected by this parameter, and is always enabled.

Default value is “0” (disabled).

Example 1.5. Set the shutdown_on_error parameter

...
# abort OpenSIPS startup if Redis is down
modparam("cachedb_redis", "shutdown_on_error", 1)
...

1.5.5. `use_tls` (integer)

Setting this parameter will allow you to use TLS for Redis connections. In order to enable TLS for a specific connection, you can use the "tls_domain=dom_name" URL parameter in the cachedb_url of this module (or other modules that use the CacheDB interface). This should be placed at the end of the URL after the '?' character.

When using this parameter, you must also ensure that tls_mgm is loaded and properly configured. Refer to the the module for additional info regarding TLS client domains.

Note that TLS is supported by Redis starting with version 6.0. Also, it is an optional feature enabled at compile time and might not be included in the standard Redis packages available for your OS.

Default value is 0 (not enabled)

Example 1.6. Set the use_tls parameter

...
modparam("tls_mgm", "client_domain", "redis")
modparam("tls_mgm", "certificate", "[redis]/etc/pki/tls/certs/redis.pem")
modparam("tls_mgm", "private_key", "[redis]/etc/pki/tls/private/redis.key")
modparam("tls_mgm", "ca_list",     "[redis]/etc/pki/tls/certs/ca.pem")
...
modparam("cachedb_redis", "use_tls", 1)
modparam("cachedb_redis", "cachedb_url","redis://localhost:6379/?tls_domain=redis")
...

1.6. Exported Functions

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

1.7. Raw Query Syntax

The cachedb_redis module allows to run RAW queries, thus taking full advantage of the capabilities of the back-end. The query syntax is the typical REDIS one.

Here are a couple examples of running some Redis queries :

Example 1.7. Redis Raw Query Examples

...
	$var(my_hash) = "my_hash_name";
	$var(my_key) = "my_key_name";
	$var(my_value) = "my_key_value";
	cache_raw_query("redis","HSET $var(my_hash) $var(my_key) $var(my_value)");
	cache_raw_query("redis","HGET $var(my_hash) $var(my_key)","$avp(result)");
	xlog("We have fetched $avp(result) \n");
...
	$var(my_hash) = "my_hash_name";
	$var(my_key1) = "my_key1_name";
	$var(my_key2) = "my_key2_name";
	$var(my_value1) = "my_key1_value";
	$var(my_value2) = "my_key2_value";
	cache_raw_query("redis","HSET $var(my_hash) $var(my_key1) $var(my_value1)");
	cache_raw_query("redis","HSET $var(my_hash) $var(my_key2) $var(my_value2)");
	cache_raw_query("redis","HGETALL $var(my_hash)","$avp(result)");

	$var(it) = 0;
	while ($(avp(result_final)[$var(it)]) != NULL) {
		xlog("Multiple key reply: - we have fetched $(avp(result_final)[$var(it)]) \n");
		$var(it) = $var(it) + 1;
	}
...

Chapter 2. Contributors

2.1. By Commit Statistics

Table 2.1. Top contributors by DevScore⁽¹⁾, authored commits⁽²⁾ and lines added/removed⁽³⁾

	Name	DevScore	Commits	Lines ++	Lines --
1.	Vlad Paiu (@vladpaiu)	33	19	1446	50
2.	Liviu Chircu (@liviuchircu)	29	19	558	277
3.	Razvan Crainea (@razvancrainea)	16	13	130	35
4.	Vlad Patrascu (@rvlad-patrascu)	12	6	595	38
5.	Bogdan-Andrei Iancu (@bogdan-iancu)	7	5	7	5
6.	Maksym Sobolyev (@sobomax)	6	4	7	7
7.	jalung	4	1	144	61
8.	Dan Pascu (@danpascu)	3	1	15	15
9.	Ezequiel Lovelle	3	1	11	4
10.	John Burke (@john08burke)	3	1	6	1

All remaining contributors: tcresson, Julián Moreno Patiño, Peter Lemenkov (@lemenkov), zhengsh, Jarrod Baumann (@jarrodb), Kristian Høgh.

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

2.2. By Commit Activity

Table 2.2. Most recently active contributors⁽¹⁾ to this module

	Name	Commit Activity
1.	Vlad Paiu (@vladpaiu)	Oct 2011 - Nov 2024
2.	tcresson	Oct 2023 - Oct 2023
3.	Liviu Chircu (@liviuchircu)	Mar 2014 - Oct 2023
4.	zhengsh	Aug 2023 - Aug 2023
5.	Maksym Sobolyev (@sobomax)	Feb 2023 - Feb 2023
6.	John Burke (@john08burke)	Apr 2022 - Apr 2022
7.	Vlad Patrascu (@rvlad-patrascu)	May 2017 - Jan 2022
8.	Bogdan-Andrei Iancu (@bogdan-iancu)	Oct 2014 - Mar 2020
9.	Razvan Crainea (@razvancrainea)	Feb 2012 - Sep 2019
10.	Dan Pascu (@danpascu)	May 2019 - May 2019

All remaining contributors: Peter Lemenkov (@lemenkov), Kristian Høgh, Julián Moreno Patiño, Jarrod Baumann (@jarrodb), jalung, Ezequiel Lovelle.

(1) including any documentation-related commits, excluding merge commits

Chapter 3. Documentation

3.1. Contributors

Last edited by: Liviu Chircu (@liviuchircu), Vlad Patrascu (@rvlad-patrascu), Peter Lemenkov (@lemenkov), Julián Moreno Patiño, Razvan Crainea (@razvancrainea), Vlad Paiu (@vladpaiu).

Chapter 4. Frequently Asked Questions

4.1.	My OpenSIPS is occasionally crashing in libhiredis, what to do?
	Make sure you've upgraded the Redis "libhiredis" client library to at least version 0.14.1. There was at least one significant vulnerability reported in library versions prior to that one (CVE-2020-7105), so upgrading to latest stable may very well fix the crash!