Handbuch:$wgShellCgroup
| Shell und Prozesskontrolle: $wgShellCgroup | |
|---|---|
| Limit shell commands memory using linux Cgroups. |
|
| Eingeführt in Version: | 1.21.0 (Gerrit change 47559; git #674962b3) |
| Entfernt in Version: | Weiterhin vorhanden |
| Erlaubte Werte: | (Zeichenkette) |
| Standardwert: | false |
| Andere Einstellungen: Alphabetisch | Nach Funktion | |
Under Linux: a cgroup directory used to constrain memory usage of shell commands. The directory must be writable by the user which runs MediaWiki.
If specified, this is used instead of ulimit, which is inaccurate, and causes malloc() to return NULL, which exposes bugs in C applications, making them segfault or deadlock.
A wrapper script will create a cgroup for each shell command that runs, as a subgroup of the specified cgroup. If the memory limit is exceeded, the kernel will send a SIGKILL signal to a process in the subgroup. (MediaWiki will often report this error as error code 137, after the bash return status of a command receiving SIGKILL)
Einrichtung
If cgroups are not set up, you may have to mount the cgroup filesystem. Als root:
mount -t tmpfs cgroup_root /sys/fs/cgroup mkdir /sys/fs/cgroup/memory mount -t cgroup cgroup_memory -omemory /sys/fs/cgroup/memory
Als Nächstes musst du MediaWiki-spezifische Konfiguration machen:
mkdir -p /sys/fs/cgroup/memory/mediawiki mkdir -m 0777 /sys/fs/cgroup/memory/mediawiki/job
The reliability of cgroup cleanup can be improved by installing a notify_on_release script in the root cgroup (This step is optional).
- Copy modules/mediawiki/files/cgroup/cgroup-mediawiki-clean from operations/puppet.git to /usr/local/bin/cgroup-mediawiki-clean
- Führe den Befehl aus
echo "/usr/local/bin/cgroup-mediawiki-clean" > /sys/fs/cgroup/memory/release_agent
Last of all, enable cgroups in your LocalSettings.php
echo '$wgShellCgroup = "/sys/fs/cgroup/memory/mediawiki/job";' >> LocalSettings.php
The reliability of cgroup cleanup can be improved by installing a notify_on_release script in the root cgroup, see e.g. gerrit:40784
Fehlerbehebung
Falls cgroup nicht funktioniert, versuche Folgendes:
- Installiere das Paket cgroup-bin
- Führe den Befehl
cat /proc/cgroupsaus If the memory subsystem has a 0 under enabled, then memory cgroups may be disabled in your kernel. Try rebooting your computer withcgroup_enable=memory swapaccount=1on the kernel command line.
- Older bash doesn't like the readarray call in limit.sh.
Du solltest mindestens Version 4.1 verwenden
Siehe auch
- cgroup-mediawiki-clean shell script