CACHEDB_LOCAL module
Admin Guide
Section titled “Admin Guide”Overview
Section titled “Overview”This module is an implementation of a local cache system designed as a hash table. It uses the Key-Value interface exported by OpenSIPS core. Starting with version 2.3, the module can have multiple hash tables, called collections. Each url for cachedb_local module points to one collection. One collection can be shared between multiple urls.
Clustering
Section titled “Clustering”Cachedb_local clustering is a mechanism used to mirror local cache changes taking place in one OpenSIPS instance to one or multiple other instances without the need of third party dependencies. The process is simplified by using the clusterer module which facilitates the management of a cluster of OpenSIPS noeds and the sending of replication-related BIN packets (binary-encoded, using proto_bin). This might be usefull for implementing a hot stand-by system, where the stand-by instance can take over without the need of filling the cache by its own.
The following cache operations will be distributet within the cluster:
- cache_store
- cache_remove
- cache_add
- cache_sub
In addition to the event-driven replication, an OpenSIPS instance will first try to learn all the local cache information from antoher node in the cluster at startup. The data synchronization mechanism requires defining one of the nodes in the cluster as a “seed” node. See the clusterer module for details on how to do this and why is it needed.
Note: You have to explicitly specify which collections you want to replicate when you set cache collections.
Limitations: The clustering operations are not atomic and constistency over the cluster nodes is not guaranteed.
Dependencies
Section titled “Dependencies”OpenSIPS Modules
Section titled “OpenSIPS Modules”The following modules must be loaded before this module:
- clusterer, if cluster id is set.
External Libraries or Applications
Section titled “External Libraries or Applications”The following libraries or applications must be installed before running OpenSIPS with this module loaded:
- none
Exported Parameters
Section titled “Exported Parameters”cachedb_url (string)
Section titled “cachedb_url (string)”URLs of local cache groups to be used used for the script and MI cacheDB operations. The parameter can be set multiple times.
One collection can belong to multiple URLs, but one URL can have only one collection. Redefining an URL with the same schema and group name will result in overwriting that URL. Each collection used in URL definition must be defined using cachedb_collection parameter. The collection shall be defined as a normal database, at the end of the URL as in the examples. In the script the collection shall be identified using the schema and, if exists, the group name.
“If no URL defined, the url with no group name and collection “default” will be used.”.
...### for this example, if no collection is defined, the default collection named### "default" shall be usedmodparam("cachedb_local", "cachedb_url", "local://")### this URL will use the collection named collection1; it will overwrite the### previous url definition which was using the "default" collectionmodparam("cachedb_local", "cachedb_url", "local:///collection1")### this URL will use collection2; it will be referenced from the script### with "local:group2"modparam("cachedb_local", "cachedb_url", "local:group2:///collection2")
## how to use the URLs from the script## as defined above, this call will use collection1cache_store("local", ...)## as defined above, this call will use collection2cache_store("local:group2", ...)...cache_collections (string)
Section titled “cache_collections (string)”Using this parameter, collections(hash tables) and their sizes can be defined. Each collection definition must be separated one from another using ’;’. Default size for a hash is 512. The size must be separated from the name of the collection using ’=’.
If clustering is enabled you have to specify which collections you want to replicate with the /r suffix to the collection name.
The “default” collection always gets created, even when not included in this list of collections.
...## creating collection1 with default size (512) and collection2 with custom size## 2^5 (32); we also changed the size of the default collection, which would have been## created anyway from 2^9 - 512 (default value) to 2^4 - 16## also, collection1 and collection2 will be replicated in the cluster, while the## default collection will be local to this nodemodparam("cachedb_local", "cache_collections", "collection1/r; collection2/r = 5; default = 4")...cache_clean_period (int)
Section titled “cache_clean_period (int)”The time interval in seconds at which to go through all the records and delete the expired ones.
Default value is “600 (10 minutes)“.
...modparam("cachedb_local", "cache_clean_period", 1200)...cluster_id (int)
Section titled “cluster_id (int)”Specifies the cluster ID which this instance will send to and receive cache data.
This OpenSIPS cluster exposes the “cachedb-local-repl” capability in order to mark nodes as eligible for becoming data donors during an arbitrary sync request. Consequently, the cluster must have at least one node marked with the “seed” value as the clusterer.flags column/property in order to be fully functional. Consult the clusterer - Capabilities chapter for more details.
Default value is 0 (replication disabled).
...modparam("cachedb_local", "cluster_id", 1)...cluster_persistency (string)
Section titled “cluster_persistency (string)”Controls the behavior of the OpenSIPS local cachedb clustering following a restart.
This parameter may take the following values:
- “none” - no explicit data synchronization following a restart. The node starts empty.
- “sync-from-cluster” - enable cluster-based restart persistency. Following a restart, an OpenSIPS cluster node will search for a healthy “donor” node from which to mirror the entire user location dataset via direct cluster sync (TCP-based, binary-encoded data transfer). This will require the configuration of one or multiple “seed” nodes in the cluster.
Default value is “sync-from-cluster”.
...modparam("cachedb_local", "cluster_persistency", "sync-from-cluster")...enable_restart_persistency (int)
Section titled “enable_restart_persistency (int)”Enable restart persistency using the persistent memory mechanism. Data is stored in a cache file that is mapped against OpenSIPS memory.
Note that you have to keep the same collection definitions from a previous run in order to use the cached data for the respective collections.
If cluster persistency is enabled as well, keys loaded from the persistent cache will be discarded if they are not received in the cluster sync data.
Default value is “0 (disabled)”.
...modparam("cachedb_local", "enable_restart_persistency", yes)...Exported Functions
Section titled “Exported Functions”cache_remove_chunk([collection,] glob)
Section titled “cache_remove_chunk([collection,] glob)”Remove all keys from local cache that match the glob pattern corresponding to a certain collection or the ‘default’ collection if none defined. Keep in mind that collection name is different than group name, which identifies the engine in cachedb operations.
Parameters:
- collection (string, optional)
- glob (string)
This function can be used from all routes
... cache_remove_chunk("myinfo_*"); cache_remove_chunk("collection1", "myinfo_*"); ...Exported MI Functions
Section titled “Exported MI Functions”cachedb_local:remove_chunk
Section titled “cachedb_local:remove_chunk”Replaces obsolete MI command: cache_remove_chunk.
Removes all local cache entries that match the provided glob param.
Parameters :
- glob - keys that match glob will be removed
- collection(optional) - collection from which the keys shall be removed; if no collection set, the default collection will be used;
MI FIFO Command Format:
opensips-cli -x mi cachedb_local:remove_chunk "keyprefix*" collectioncachedb_local:fetch_chunk
Section titled “cachedb_local:fetch_chunk”Replaces obsolete MI command: cache_fetch_chunk.
Fetches all local cache entries that match the provided glob param.
Parameters :
- glob - keys that match glob will be returned
- collection(optional) - collection from which the keys shall be retrieved; if no collection set, the default collection will be used;
MI FIFO Command Format:
opensips-cli -x mi cachedb_local:fetch_chunk "keyprefix*" collection{ "keys": [ { "name": "keyprefix_1", "value": "key 1 data here" }, { "name": "keyprefix_2", "value": "key 2 data here" } ]}Frequently Asked Questions
Section titled “Frequently Asked Questions”Q: What happened with old cache_table_size parameter?
The parameter was removed because it was redundant. Since the addition of collections, the old hash now belongs to the default collection. This collection is created every time and it has a default size of 512. The size can be changed by setting the default collection size using cache_collections paramter.
Contributors
Section titled “Contributors”By Commit Statistics
Section titled “By Commit Statistics”Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| # | Name | DevScore | Commits | Lines++ | Lines— |
|---|---|---|---|---|---|
| 1. | Vlad Paiu (@vladpaiu) | 35 | 11 | 1335 | 693 |
| 2. | Vlad Patrascu (@rvlad-patrascu) | 26 | 16 | 532 | 249 |
| 3. | Liviu Chircu (@liviuchircu) | 24 | 18 | 201 | 227 |
| 4. | Bogdan-Andrei Iancu (@bogdan-iancu) | 16 | 14 | 46 | 50 |
| 5. | Anca Vamanu | 14 | 5 | 750 | 65 |
| 6. | Razvan Crainea (@razvancrainea) | 11 | 9 | 27 | 17 |
| 7. | Stefan Darius | 11 | 5 | 435 | 67 |
| 8. | Andrei Dragus | 10 | 4 | 183 | 182 |
| 9. | Ionut Ionita (@ionutrazvanionita) | 10 | 3 | 550 | 92 |
| 10. | Fabian Gast (@fgast) | 9 | 3 | 517 | 48 |
All remaining contributors: Maksym Sobolyev (@sobomax), Peter Lemenkov (@lemenkov), Dusan Klinec (@ph4r05), Ryan Bullock (@rrb3942), Zero King (@l2dy), Julián Moreno Patiño.
(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
(3) ignoring whitespace edits, renamed files and auto-generated files
By Commit Activity
Section titled “By Commit Activity”| # | Name | Commit Activity |
|---|---|---|
| 1. | Stefan Darius | Jun 2026 - Jul 2026 |
| 2. | Razvan Crainea (@razvancrainea) | Aug 2015 - Jun 2026 |
| 3. | Liviu Chircu (@liviuchircu) | Mar 2014 - Sep 2024 |
| 4. | Vlad Paiu (@vladpaiu) | Oct 2011 - Feb 2024 |
| 5. | Maksym Sobolyev (@sobomax) | Jan 2021 - Feb 2023 |
| 6. | Vlad Patrascu (@rvlad-patrascu) | Jan 2017 - Oct 2022 |
| 7. | Zero King (@l2dy) | Mar 2020 - Mar 2020 |
| 8. | Peter Lemenkov (@lemenkov) | Jun 2018 - Feb 2020 |
| 9. | Bogdan-Andrei Iancu (@bogdan-iancu) | Jan 2009 - Apr 2019 |
| 10. | Fabian Gast (@fgast) | Dec 2018 - Dec 2018 |
All remaining contributors: Ionut Ionita (@ionutrazvanionita), Julián Moreno Patiño, Dusan Klinec (@ph4r05), Ryan Bullock (@rrb3942), Andrei Dragus, Anca Vamanu.
(1) including any documentation-related commits, excluding merge commits
Documentation
Section titled “Documentation”Contributors
Section titled “Contributors”Last edited by: Razvan Crainea (@razvancrainea), Liviu Chircu (@liviuchircu), Vlad Paiu (@vladpaiu), Vlad Patrascu (@rvlad-patrascu), Zero King (@l2dy), Bogdan-Andrei Iancu (@bogdan-iancu), Fabian Gast (@fgast), Peter Lemenkov (@lemenkov), Ionut Ionita (@ionutrazvanionita), Andrei Dragus, Anca Vamanu.
License
Section titled “License”All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0