moodle/moodle
3
0
Fork 0
mirror of https://github.com/moodle/moodle.git synced 2025-08-04 08:26:37 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

MDL-19711 dml: Enable use of readonly slave database handles

Browse source 
Implemented with moodle_read_slave_trait

Functionality is triggered by supplying config dboption['readonly'].
See config-dist.php for more info on supported dboptions.

pgsql and mysqli drivers are using this feature. Also added support for
connection timeout for these two drivers.
This commit is contained in:
Srdjan 2020-05-07 14:14:29 +10:00
parent d85118369d
commit 46cfde3d95
19 changed files with 2422 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files

39
config-dist.php
View file

@ -79,6 +79,45 @@ $CFG->dboptions = array(
// set to zero if you are using pg_bouncer in
// 'transaction' mode (it is fine in 'session'
// mode).
/*
'connecttimeout' => null, // Set connect timeout in seconds. Not all drivers support it.
'readonly' => [ // Set to read-only slave details, to get safe reads
// from there instead of the master node. Optional.
// Currently supported by pgsql and mysqli variety classes.
// If not supported silently ignored.
'instance' => [ // Readonly slave connection parameters
[
'dbhost' => 'slave.dbhost',
'dbport' => '', // Defaults to master port
'dbuser' => '', // Defaults to master user
'dbpass' => '', // Defaults to master password
],
[...],
],
Instance(s) can alternatively be specified as:
'instance' => 'slave.dbhost',
'instance' => ['slave.dbhost1', 'slave.dbhost2'],
'instance' => ['dbhost' => 'slave.dbhost', 'dbport' => '', 'dbuser' => '', 'dbpass' => ''],
'connecttimeout' => 2, // Set read-only slave connect timeout in seconds. See above.
'latency' => 0.5, // Set read-only slave sync latency in seconds.
// When 'latency' seconds have lapsed after an update to a table
// it is deemed safe to use readonly slave for reading from the table.
// It is optional. If omitted once written to a table it will always
// use master handle for reading.
// Lower values increase the performance, but setting it too low means
// missing the master-slave sync.
'exclude_tables' => [ // Tables to exclude from read-only slave feature.
'table1', // Should not be used, unless in rare cases when some area of the system
'table2', // is malfunctioning and you still want to use readonly feature.
], // Then one can exclude offending tables while investigating.
More info available in lib/dml/moodle_read_slave_trait.php where the feature is implemented.
]
*/
// For all database config settings see https://docs.moodle.org/en/Database_settings
);