Job queue

Job queue on Wikipedia
Job queue on Mediawiki

The job queue in MediaWiki is a system designed to handle tasks that are too time-consuming or resource-intensive to be performed during a normal web request-response cycle.

The job queue allows MediaWiki to defer tasks that do not need immediate execution. This includes operations like updating link tables when templates change, sending notification emails, re-rendering pages after template edits, or any batch processing tasks.

USApedia reference

Example

Cron job

#!/bin/bash
# Put the MediaWiki installation path on the line below
MW_INSTALL_PATH="/home/www/www.mywikisite.example/mediawiki"
RUN_JOBS="$MW_INSTALL_PATH/maintenance/runJobs.php --maxtime=60"
echo Starting job service...
# Wait a minute after the server starts up to give other processes time to get started
sleep 1
echo Started.
while true; do
	# Job types that need to be run ASAP no matter how many of them are in the queue
	# Those jobs should be very "cheap" to run
	php $RUN_JOBS --type="enotifNotify"
	# Everything else, limit the number of jobs on each batch
	# The <tvar name=1>--wait</tvar> parameter will pause the execution here until new jobs are added,
	# to avoid running the loop without anything to do
	php $RUN_JOBS --wait --maxjobs=20
	# Wait some seconds to let the CPU do other things, like handling web requests, etc.
	echo  Waiting for 10 seconds...
	sleep 10
done

Docker

* * * * * docker exec web php maintenance/runJobs.php --maxjobs 700 --maxtime=55

sudo crontab -e

Errors

  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 20480 bytes) in /var/www/mediawiki/w/includes/parser/Preprocessor_Hash.php on line 704
  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 20480 bytes) in /var/www/mediawiki/w/includes/parser/Preprocessor_Hash.php on line 709
  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 1744896 bytes) in /var/www/mediawiki/w/includes/libs/objectcache/MediumSpecificBagOStuff.php on line 1091
  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 1310720 bytes) in /var/www/mediawiki/w/includes/parser/StripState.php on line 94
  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 262144 bytes) in /var/www/mediawiki/w/includes/parser/Parser.php on line 3916
  • PHP Fatal error:  Allowed memory size of 157286400 bytes exhausted (tried to allocate 614400 bytes) in /var/www/mediawiki/w/includes/tidy/RemexCompatFormatter.php on line 88

External