dns_cache Module

Vladut-Stefan Paiu

OpenSIPS Solutions

Edited by

Vladut-Stefan Paiu

Copyright © 2012 www.opensips-solutions.com

Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSIPS Modules
1.3. Exported Parameters
1.3.1. cachedb_url (string)
1.3.2. blacklist_timeout (int)
1.4. Exported Functions

List of Examples

1.1. Set cachedb_url parameter
1.2. Set blacklist_timeout parameter

Chapter 1. Admin Guide

1.1. Overview

This module is an implementation of a cache system designed for DNS records. For succesfull DNS queries of all types, the module will store in a cache/db backend the mappings, for TTL number of seconds received in the DNS answer. Failed DNS queries will also be stored in the back-end, with a TTL that can be specified by the user. The module uses the Key-Value interface exported from the core.

1.2. Dependencies

1.2.1. OpenSIPS Modules

A cachedb_* type module must be loaded before loading the dns_cache module.

1.3. Exported Parameters

1.3.1. cachedb_url (string)

The url of the key-value back-end that will be used for storing the DNS records.

Example 1.1. Set cachedb_url parameter

...
#use internal cachedb_local module
modparam("dns_cache", "cachedb_url","local://")
#use cachedb_memcached module with memcached server at 192.168.2.130
modparam("dns_cache", "cachedb_url","memcached://192.168.2.130:8888/")
...

1.3.2. blacklist_timeout (int)

The number of seconds that a failed DNS query will be kept in cache. Default is 3600.

Example 1.2. Set blacklist_timeout parameter

...
modparam("dns_cache", "blacklist_timeout",7200) # 2 hours
...

1.4. Exported Functions

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