Details

Use this to override lag information. Generally a hook function should only replace $lagInfo if the new $lagInfo['lag'] is greater than the current $lagInfo['lag'].

• &$lagInfo: Maximum lag information array. Fields in the array are:
  • 'lag' is the number of seconds of lag.
  • 'host' is the host name on which the lag exists.
  • 'type' is an indication of the type of lag, e.g. "db" for database replication lag or "jobqueue" for job queue size converted to pseudo-seconds.
  • It is possible to add more fields and they will be returned to the user in the API response.

Example

To make bots back off if the job queue grows too large, by translating jobs into maxlag “seconds” (with an arbitrary factor, here 1000, that you’d want to adjust for your own wiki), you might use:

$wgHooks['ApiMaxLagInfo'][] = function ( &$lagInfo ): void {
	$jobs = \MediaWiki\SiteStats\SiteStats::jobs();
	if ( $jobs <= 0 ) {
		return;
	}
	$lag = (float)$jobs / 1000.0;
	if ( $lag <= $lagInfo['lag'] ) {
		return;
	}
	$server = \MediaWiki\MediaWikiServices::getInstance()->getMainConfig()->get( \MediaWiki\MainConfigNames::Server );
	$host = wfParseUrl( $server )['host'];
	$lagInfo = [
		'lag' => $lag,
		'host' => $host,
		'type' => 'jobqueue',
		'jobs' => $jobs,
	];
};