cachedb_mongodb Module

Vladut-Stefan Paiu

OpenSIPS Solutions

Edited by

Vladut-Stefan Paiu


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. exec_threshold (int)
1.5.3. compat_mode_2.4 (int)
1.5.4. compat_mode_3.0 (int)
1.6. Exported Functions
1.7. Raw Query Syntax

List of Examples

1.1. Runtime requirements for "cachedb_mongodb"
1.2. Compilation requirements for "cachedb_mongodb"
1.3. Set cachedb_url parameter
1.4. Use MongoDB servers
1.5. Set exec_threshold parameter
1.6. Setting the compat_mode_2.4 parameter
1.7. Setting the compat_mode_3.0 parameter
1.8. MongoDB Raw Insert
1.9. MongoDB Raw Update

Chapter 1. Admin Guide

1.1. Overview

This module is an implementation of a cache system designed to work with MongoDB servers. It implements the Key-Value interface exposed by the OpenSIPS core.

The underlying client library is compatible with any of the following MongoDB server versions: 2.4, 2.6, 3.0, 3.2 and 3.4, as stated in the MongoDB documentation.

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 MongoDB is also persistent so it can also be restarted without loss of information.

  • MongoDB is an open-source project so it can be used to exchange data with various other applications

  • By creating a MongoDB Cluster, multiple OpenSIPS instances can easily share key-value information

  • This module also implements the CacheDB Raw query capability, thus you can run whatever query that the MongoDB back-end supports, taking full advatange of it.

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 packages must be installed before running OpenSIPS with this module loaded:

Example 1.1. Runtime requirements for "cachedb_mongodb"

# Debian / Ubuntu
sudo apt-get install libjson-c2 libmongoc-1.0

# Red Hat / CentOS
sudo yum install json-c mongo-c-driver
				


The following packages are required in order to compile this module:

Example 1.2. Compilation requirements for "cachedb_mongodb"

# Debian / Ubuntu
sudo apt-get install libjson-c-dev libmongoc-dev libbson-dev

# Red Hat / CentOS
sudo yum install json-c-devel mongo-c-driver-devel
				


1.5. Exported Parameters

1.5.1. cachedb_url (string)

The URLs of the server groups that OpenSIPS will connect to in order to allow the cache_store(), cache_fetch(), etc. functions to be used from the OpenSIPS script. 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.

The URL syntax is identical to the one used by MongoDB, including connect string options. For more info, please refer to the official MongoDB connect string documentation.

Example 1.3. Set cachedb_url parameter

...
modparam("cachedb_mongodb", "cachedb_url","mongodb:instance1://localhost:27017/db.collection")
modparam("cachedb_mongodb", "cachedb_url","mongodb:replicaset1://1.2.3.4:27017,2.3.4.5:27017,3.4.5.6:27017/db.collection?replicaSet=test")
...
	

Example 1.4. Use MongoDB servers

...
cache_store("mongodb:group1", "key", "$ru value");
cache_fetch("mongodb:replicaset1", "key", $avp(10));
cache_remove("mongodb:cluster1", "key");
...
	

1.5.2. exec_threshold (int)

The maximum number of microseconds that a mongodb query can last. Anything above the threshold will trigger a warning message to the log

Default value is 0 ( unlimited - no warnings ).

Example 1.5. Set exec_threshold parameter

...
modparam("cachedb_mongodb", "exec_threshold", 100000)
...
	

1.5.3. compat_mode_2.4 (int)

Switch the module into compatibility mode for MongoDB 2.4 servers. Specifically, this allows "insert/update/delete" raw queries to not fail, since they were introduced in MongoDB 2.6. The module will interpret the raw query JSON, convert it to its corresponding command and run it.

Caveat: only the minimally required raw query options are supported in this mode.

Default value is 0 (disabled).

Example 1.6. Setting the compat_mode_2.4 parameter

...
modparam("cachedb_mongodb", "compat_mode_2.4", 1)
...
	

1.5.4. compat_mode_3.0 (int)

Switch the module into compatibility mode for MongoDB 2.6/3.0 servers. Specifically, this allows "find" raw queries to not fail, since they were introduced in MongoDB 3.2. The module will interpret the "find" raw query JSON, convert it to its corresponding command and run it.

Caveat: only the minimally required options for "find" raw queries are supported in this mode.

Default value is 0 (disabled).

Example 1.7. Setting the compat_mode_3.0 parameter

...
modparam("cachedb_mongodb", "compat_mode_3.0", 1)
...
	

1.6. Exported Functions

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

1.7. Raw Query Syntax

The cachedb_mongodb module supports raw queries, thus taking full advantage of the capabilities of the back-end, including query-specific options such as read/write preference, timeouts, filtering options, etc.

The query syntax is identical to the mongo cli. Documentation for it can be found on the MongoDB website. Query results are returned as JSON documents, that one can further process in the OpenSIPS script by using the JSON module.

Some example raw queries:

Example 1.8. MongoDB Raw Insert

...
cache_raw_query("mongodb:cluster", "{ \
    \"insert\": \"ip_blacklist\", \
    \"documents\": [{ \
        \"username\": \"$fU\", \
        \"ip\": \"$si\", \
        \"attempts\": 1 \
     }]}",
 "$avp(out)");
xlog("INSERT RAW QUERY returned $rc, output: '$avp(out)'\n");
...
			


Example 1.9. MongoDB Raw Update

...
cache_raw_query("mongodb:cluster", "{ \
    \"update\": \"ip_blacklist\", \
    \"updates\": [{ \
        \"q\": { \
            \"username\": \"$fU\", \
            \"ip\": \"$si\" \
         }, \
        \"u\": { \
            \"$$inc\": {\"attempts\": 1} \
         } \
      }]}",
 "$avp(out)");
xlog("UPDATE RAW QUERY returned $rc, output: '$avp(out)'\n");
...