High amount of sw-engine processes in process list hung on config.lock file – Plesk Help Center

Applicable to:

Plesk Onyx for Linux

Note: This article has the reference to the issue with the fix available:

#PPPM-8929 "Installation of extensions no longer causes sw-engine scripts and CLI utilities to hang."
Fixed in:
- Plesk Onyx 17.8.11 Update 32 26 November 2018

Please consider updating your server:

Symptoms

Scheduled backups are not created.
Plesk utilities, e.g.:

# plesk login

hang.
There are lot of sw-engine processes:

# ps -e fwww | grep sw-engine
6846 ? S 2:37 _ sw-engine-fpm: pool plesk
6890 ? S 2:37 _ sw-engine-fpm: pool plesk
6903 ? S 2:36 _ sw-engine-fpm: pool plesk
6904 ? S 2:36 _ sw-engine-fpm: pool plesk
6918 ? S 2:36 _ sw-engine-fpm: pool plesk
6920 ? S 2:36 _ sw-engine-fpm: pool plesk
6921 ? S 2:37 _ sw-engine-fpm: pool plesk
6924 ? S 2:36 _ sw-engine-fpm: pool plesk
6936 ? S 2:37 _ sw-engine-fpm: pool plesk
6939 ? S 2:36 _ sw-engine-fpm: pool plesk

OR

# ps -e fwww | grep sw-engine

24695 ? Zs 0:00 | _ [sw-engine] <defunct>
24875 ? Zs 0:00 | _ [sw-engine] <defunct>
29217 ? Zs 0:00 | _ [sw-engine] <defunct>
31327 ? Zs 0:00 | _ [sw-engine] <defunct>
15254 ? Zs 0:00 | _ [sw-engine] <defunct>
16243 ? Zs 0:00 | _ [sw-engine] <defunct>
19463 ? Zs 0:00 | _ [sw-engine] <defunct>
20472 ? Zs 0:00 | _ [sw-engine] <defunct>
13502 ? Zs 0:00 | _ [sw-engine] <defunct>
15067 ? Zs 0:00 | _ [sw-engine] <defunct>
The strace output of such processes contains the following:

# strace -p6846

<...>

restart_syscall(<... resuming interrupted futex ...>) = -1 ETIMEDOUT (Connection timed out)
fcntl(9, F_SETLKW, {l_type=F_RDLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
fcntl(7, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
fcntl(7, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
fcntl(7, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
fcntl(7, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=0}) = 0
umask(02) = 022
stat("/run/lock/lmlib/container_locks/plesk.0/node.1/service", {st_mode=S_IFDIR|S_ISGID|0775, st_size=60, ...}) = 0
umask(022) = 02
umask(0111) = 022
creat("/run/lock/lmlib/container_locks/plesk.0/node.1/service/config.lock", 0777) = 10
close(10) = 0
umask(022) = 0111
In case of Multi-Server installation, Service Nodes are going offline periodically during the Daily Maintenance Task execution.

Cause

This is Plesk bug with ID #PPPM-8929 that is fixed in Plesk Onyx 17.8 MU 32.

Resolution

Upgrade to Plesk Onyx 17.8 or install latest Plesk updates in case already running Plesk Onyx 17.8.

Note: In case it is not possible, see Additional Information section at the bottom.

Workaround for older Plesk versions

Connect to the server via SSH.
Kill all sw-engine processes:

# pkill sw-engine
Restart sw-cp-server and sw-engine services:

# service sw-engine restart
# service sw-cp-server restart
Uninstall New Relic extension:

# plesk bin extension --uninstall new-relic

Additional Information

In case upgrade is not an option, try using the ApiCli.zip from the attachment.

Note that the fix was not fully tested yet was working fine on some installations.

# wget https://support.plesk.com/hc/en-us/article_attachments/360010352974/ApiCli.zip
# unzip ApiCli.zip
# mv /usr/local/psa/admin/plib/pm/ApiCli.php{,.bkp}
# cp -a ApiCli.php /usr/local/psa/admin/plib/pm/

ApiCli.zip
8 KB Download

Comments

2 comments

Csteamleads July 12, 2018 19:29

You will not be able to log into Plesk if you kill all sw-engine processes. You'll likely need to start/restart it as well:

pkill sw-engine; systemctl restart sw-engine

or

pkill sw-engine; service sw-engine restart

0

Ivan Postnikov July 13, 2018 17:31

Hello @Csteamleads,

thank you for noticing. The article will be reviewed and updated soon.

0

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