Table of Contents
List of Tables
List of Examples
cache_table parameter usagespec_delimiter parameter usagepvar_delimiter parameter usagecolumns_delimiter parameter usagesql_fetch_nr_rows parameter usagefull_caching_expire parameter usagereload_interval parameter usagesql_cacher_reload usagesql_cached_value(id{sep}col{sep}key) pseudo-variable usagecache_table parameterThe sql_cacher module introduces the possibility to cache data from a SQL-based database (using different OpenSIPS modules which implement the DB API) into a cache system implemented in OpenSIPS through the CacheDB Interface. This is done by specifying the databases URLs, SQL table to be used, desired columns to be cached and other details in the OpenSIPS configuration script.
The cached data is available in the script through the read-only pseudovariable “$sql_cached_value” similar to a Key-Value system. A specified column from the SQL table has the role of “key” therefore the value of this column along with the name of a required column are provided as "parameters" to the pseudovariable returning the appropriate value of the column.
There are two types of caching available:
full caching - the entire SQL table (all the rows) is loaded into the cache at OpenSIPS startup;
on demand - the rows of the SQL table are loaded at runtime when appropriate keys are requested.
For on demand caching, the stored values have a configurable expire period after which they are permanently removed unless an MI reload function is called for a specific key. In the case of full caching the data is automatically reloaded at a configurable interval. Consequently if the data in the SQL database changes and a MI reload function is called, the old data remains in cache only until it expires.
The following modules must be loaded before this module:
The OpenSIPS modules that offer actual database back-end connection
This parameter can be set multiple times in order to cache multiple SQL tables or even the same table but with a different configuration. The module distinguishes those different entries by an “id” string.
The caching entry is specified via this parameter that has it's own subparameters. Each of those parameters are separated by a delimiter configured by spec_delimiter and have the following format:
param_name=param_value
The parameters are:
id : cache entry id
db_url : the URL of the SQL database
cachedb_url : the URL of the CacheDB database
table : SQL database table name
key : SQL database column name of the “key” column
columns : names of the columns to be cached from the SQL database, separated by a delimiter configured by columns_delimiter.
If not present, all the columns from the table will be cached
on_demand : specifies the type of caching:
0 : full caching
1 : on demand
If not present, default value is “0”
expire : expire period for the values stored in the cache for the on demand caching type in seconds
If not present, default value is “1 hour”
The parameters must be given in the exact order specified above.
Overall, the parameter does not have a default value, it must be set at least once in order to cache any table.
Example 1.1. cache_table parameter usage
modparam("sql_cacher", "cache_table",
"id=caching_name
db_url=mysql://root:opensips@localhost/opensips_2_2
cachedb_url=mongodb:mycluster://127.0.0.1:27017/db.col
table=table_name
key=column_name_0
columns=column_name_1 column_name_2 column_name_3
on_demand=0")
The delimiter to be used in the caching entry specification provided in the cache_table parameter to separate the subparameters. It must be a single character.
The default value is newline.
The delimiter to be used in the “$sql_cached_value” pseudovariable to separate the caching id, the desired column name and the value of the key. It must be a single character.
The default value is “:”.
The delimiter to be used in the columns subparameter of the caching entry specification provided in the cache_table parameter to separate the desired columns names. It must be a single character.
The default value is “ ”(space).
The number of rows to be fetched into OpenSIPS private memory in one chunk from the SQL database driver. When querying large tables, adjust this parameter accordingly to avoid the filling of OpenSIPS private memory.
The default value is “100”.
Reloads the entire SQL table in cache for full caching or the specified key for on demand caching.
The first parameter is the caching id.
The second parameter must be a value of the key column from the SQL table. For full caching this parameter is not needed.
Example 1.8. sql_cacher_reload usage
... $ opensipsctl fifo sql_cacher_reload caching_name ... $ opensipsctl fifo sql_cacher_reload caching_name key ...
The cached data is available through this read-only PV.The format is the following:
sep : separator configured by pvar_delimiter
id : cache entry id
col : name of the required column
key : value of the “key” column
Example 1.9. sql_cached_value(id{sep}col{sep}key) pseudo-variable usage
... $avp(a) = $sql_cached_value(caching_name:column_name_1:key1); ...
This section provides an usage example for the caching of an SQL table.
Suppose one in interested in caching the columns: “host_name”, “reply_code”, “flags” and “next_domain” from the “carrierfailureroute” table of the OpenSIPS database.
Example 1.10. Example database content - carrierfailureroute table
... +----+---------+-----------+------------+--------+-----+-------------+ | id | domain | host_name | reply_code | flags | mask | next_domain | +----+---------+-----------+------------+-------+------+-------------+ | 1 | 99 | | 408 | 16 | 16 | | | 2 | 99 | gw1 | 404 | 0 | 0 | 100 | | 3 | 99 | gw2 | 50. | 0 | 0 | 100 | | 4 | 99 | | 404 | 2048 | 2112 | asterisk-1 | +----+---------+-----------+------------+-------+------+-------------+ ...
In the first place, the details of the caching must be provided by setting the module parameter “cache_table” in the OpenSIPS configuration script.
Example 1.11. Setting the cache_table parameter
modparam("sql_cacher", "cache_table",
"id=carrier_fr_caching
db_url=mysql://root:opensips@localhost/opensips
cachedb_url=mongodb:mycluster://127.0.0.1:27017/my_db.col
table=carrierfailureroute
key=id
columns=host_name reply_code flags next_domain")
Next, the values of the cached columns ca be accessed through the “$sql_cached_value” PV.
Example 1.12. Accessing cached values
...
$avp(rc1) = $sql_cached_value(carrier_fr_caching:reply_code:1);
$avp(rc2) = $sql_cached_value(carrier_fr_caching:reply_code:2);
...
var(some_id)=4;
$avp(nd) = $sql_cached_value(carrier_fr_caching:next_domain:$var(some_id));
...
xlog("host name is: $sql_cached_value(carrier_fr_caching:host_name:2)");
...
Table 2.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| Name | DevScore | Commits | Lines ++ | Lines -- | |
|---|---|---|---|---|---|
| 1. | Vlad Patrascu (@rvlad-patrascu) | 63 | 23 | 3116 | 792 |
| 2. | Liviu Chircu (@liviuchircu) | 8 | 6 | 64 | 46 |
| 3. | Razvan Crainea (@razvancrainea) | 8 | 6 | 14 | 8 |
| 4. | Bogdan-Andrei Iancu (@bogdan-iancu) | 4 | 2 | 4 | 4 |
| 5. | Ionel Cerghit (@ionel-cerghit) | 4 | 1 | 50 | 92 |
| 6. | Ovidiu Sas (@ovidiusas) | 3 | 1 | 1 | 1 |
(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
Table 2.2. Most recently active contributors(1) to this module
| Name | Commit Activity | |
|---|---|---|
| 1. | Liviu Chircu (@liviuchircu) | Mar 2016 - Nov 2018 |
| 2. | Vlad Patrascu (@rvlad-patrascu) | Aug 2015 - Nov 2018 |
| 3. | Bogdan-Andrei Iancu (@bogdan-iancu) | May 2017 - Jun 2018 |
| 4. | Razvan Crainea (@razvancrainea) | Feb 2016 - Apr 2017 |
| 5. | Ovidiu Sas (@ovidiusas) | Mar 2017 - Mar 2017 |
| 6. | Ionel Cerghit (@ionel-cerghit) | Dec 2015 - Dec 2015 |
(1) including any documentation-related commits, excluding merge commits
Last edited by: Liviu Chircu (@liviuchircu), Vlad Patrascu (@rvlad-patrascu), Bogdan-Andrei Iancu (@bogdan-iancu).
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