Bug ID 724556: icrd_child spawns more than maximum allowed times (zombie processes)

Last Modified: Oct 16, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6

Fixed In:
15.0.0, 14.1.2.7, 13.1.3.2, 12.1.5.3

Opened: Jun 18, 2018

Severity: 2-Critical

Symptoms

icrd_child is issued a SIGTERM. The SIGTERM might not succeed in destroying the process, especially if the system is under a lot of load. This leads to zombie processes.

Impact

There are zombie icrd_child processes consuming memory.

Conditions

-- The icrd_child process is issued a SIGTERM that does not successfully destroy the icrd_child process. -- System under heavy load.

Workaround

Restart the system.

Fix Information

Introduced the following configuration in /etc/icrd.conf: sigkillDelaySeconds If set to 0, or if missing from icrd.conf, SIGKILL will not be issued after SIGTERM is issued to the icrd_child process. If set to greater than 0, after the specified delay, SIGKILL will be issued after SIGTERM is issued to the icrd_child process if icrd_child process is not terminated. A 'safe' number for the delay may be 3 seconds, but will depend on your configuration.

Behavior Change

Introduced the following configuration in /etc/icrd.conf: sigkillDelaySeconds If set to 0, or if missing from icrd.conf, SIGKILL will not be issued after SIGTERM is issued to the icrd_child process. If set to greater than 0, after the specified delay, SIGKILL will be issued after SIGTERM is issued to the icrd_child process if icrd_child process is not terminated. A 'safe' number for the delay may be 3 seconds, but will depend on your configuration.

Guides & references

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