Manual:ジョブ キュー

From MediaWiki.org
Jump to: navigation, search
This page is a translated version of the page Manual:Job queue and the translation is 42% complete.

Other languages:
Deutsch • ‎English • ‎français • ‎Bahasa Indonesia • ‎日本語 • ‎polski • ‎русский • ‎Tiếng Việt • ‎中文

MediaWiki 1.6 でジョブキューが導入され、長い処理を非同期的に実行できるようになりました。 このジョブキューは、バッチ処理を使用して短時間のタスクを多数保持するよう設計されています。

Set up[edit]

Whenever possible, you must set $wgJobRunRate to 0, and then use some sort of scheduler to run jobs completely in the background. For instance, if you were to use cron to run the jobs every day at midnight you would enter in your crontab file:

0 0 * * * /usr/bin/php /var/www/wiki/maintenance/runJobs.php > /var/log/runJobs.log 2>&1

ページ リクエストの際のジョブ実行[edit]

By default, each time a page request runs, one job is taken from the job queue and executed. This behavior is controlled by the $wgJobRunRateManual:$wgJobRunRate configuration variable. Setting this variable to 1, will run a job on each request. Setting this variable to a number between 1 and 0 will execute a job on average every 1 / $wgJobRunRate requests. Setting this variable to 0 will disable the execution of jobs during page requests completely, but you should run runJobs.phpManual:runJobs.php manually or periodically.

MediaWiki バージョン: 1.23

When enabled, jobs will be executed opening a socket and making an internal HTTP request to an unlisted special page: SpecialRunJobs.php. asynchronous の節を参照してください。

パフォーマンスの問題点[edit]

If the performance burden of this is too great, you can reduce $wgJobRunRateManual:$wgJobRunRate by putting something like this in your LocalSettings.php:

$wgJobRunRate = 0.01;

Manual usage[edit]

There is also a way to empty the job queue manually, for example after changing a template that's present on many pages. Simply run the maintenance/runJobs.phpManual:runJobs.php maintenance script. 例:

/path-to-my-wiki/maintenance$ php ./runJobs.php


履歴[edit]

非同期[edit]

The configuration variable $wgRunJobsAsyncManual:$wgRunJobsAsync has been added to force the execution of jobs synchronously, in scenarios where making an internal HTTP request for job execution is not wanted.

When running jobs asynchronously, it will open an internal HTTP connection for handling the execution of jobs, and will return the contents of the page immediately to the client without waiting for the job to complete. Otherwise, the job will be executed in the same process and the client will have to wait until the job is completed. When the job does not run asynchronously, if a fatal error occurs during job execution, it will propagate to the client, aborting the load of the page.

Note that even if $wgRunJobsAsync is set to true, if PHP can't open a socket to make the internal HTTP request, it will fallback to the synchronous job execution. However, there are a variety of situations where this internal request may fail, and jobs won't be run, without falling back to the synchronous job execution. Starting with MediaWiki 1.28.1 and 1.27.2, $wgRunJobsAsync now defaults to false. There are some configurations that can cause the asynchronous job execution to fail:

MediaWiki 1.22 での変更点[edit]

In MediaWiki 1.22MediaWiki 1.22, the job queue execution on each page request was changed (Gerrit change 59797) so, instead of executing the job inside the same PHP process that's rendering the page, a new PHP cli command is spawned to execute runJobs.phpManual:runJobs.php in the background. It will only work if $wgPhpCliManual:$wgPhpCli is set to an actual path or safe mode is off, otherwise, the old method will be used.

This new execution method could cause some problems:

There's no way to revert to the old on-request job queue handling, besides setting $wgPhpCliManual:$wgPhpCli to false, for example, which may cause other problems (タスク T63387). It can be disabled completely by setting $wgJobRunRate = 0;, but jobs will no longer run on page requests, and you must explicitly run runJobs.php to periodically run pending jobs.

MediaWiki 1.23 での変更点[edit]

In MediaWiki 1.23, the 1.22 execution method is abandoned, and jobs are triggered by MediaWiki making an HTTP connection to itself.

It was first designed as an API entry point (Gerrit change 113038) but later changed to be the unlisted special page Special:RunJobs (Gerrit change 118336).

While it solves various bugs introduced in 1.22, it still requires loading a lot of PHP classes in memory on a new process to execute a job, and also makes a new HTTP request that the server must handle.

ジョブの例[edit]

Updating links tables when a template changes[edit]

When a template changes, MediaWiki adds a job to the job queue for each article transcluding that template. Each job is a command to read an article, expand any templates, and update the link table accordingly. So null edits are no longer necessary, although it may take a while for big operations to complete. This can help to ease strain on a virtual person.

HTML キャッシュの無効化[edit]

大量のページに相当する既存のHTMLキャッシュを一気に無効にしてしまう操作は、〔テンプレートの改訂だけでなく〕より幅広い種類にわたります:

  • 画像の改訂(すべてのサムネイルを作り直し、大きさも再計算する必要があります)
  • ページの削除(すべてのリンク元でのリンクの色を、青から赤にする必要があります)
  • ページの作成、または復帰〔被削除物の回復。undelete。復活とも〕(上記同様ですが、反対に赤から青にします)
  • テンプレートの改訂(テンプレートの参照読み込みされたページ〔のキャッシュ〕をすべて更新する必要があります)

テンプレートの改訂を除くこれらの操作の結果、リンクの表〔の内容〕が無効になることはありませんが、一方で、当該ページのリンク元の、あるいは当該画像の使用先の、すべてのページのHTMLキャッシュが無効になります。 1ページ分のキャッシュを無効にする処理はごく短く、必要なのはデータベースのフィールドを1件更新し、マルチキャストのパケットを1つ発してキャッシュを消すことだけです。 しかしそれが1000件以上もある場合には、かなり時間がかかります。初期設定では、500ページ分以上を無効化する必要のある場合のみ、500ページあたり1件の処理項目が〔ジョブキューに〕発生します ($wgUpdateRowsPerJobManual:$wgUpdateRowsPerJob を参照)。

典型的な値[edit]

低負荷の期間に、ジョブキューはゼロであるかもしれません。 Wikimedia でのジョブキューは、実際ほとんどゼロではありません。 混雑していない時間帯では数百から千であるかもしれません。 混雑している日の間では、それは数百万でもあり、10%以上素早く上下します。 [1]

Special:Statistics[edit]

MediaWiki 1.16 まで、ジョブキューの長さは Special:Statistics に表示されました。 1.17 (rev:75272) からそれは取り除かれて API:SiteinfoAPI:Siteinfo で確認できます:

The number of jobs returned in the API result may be slightly inaccurate when using MySQL, which estimates the number of jobs in the database. This number can fluctuate based on the number of jobs that have recently been added or deleted. For other databases that do not support fast result-size estimation, the actual number of jobs is given.

開発者向け[edit]

関連項目[edit]