Bug ID 557281: The audit_forwarder process fails to exit normally causing the process to consume CPU to near 100%

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.1 HF1, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.4.1, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.1.0, 12.0.0 HF3, 11.6.1 HF1, 11.5.4 HF2

Opened: Nov 10, 2015

Severity: 3-Major

Related Article: K23064374

Symptoms

audit_forwarder and mcpd consume almost 100% CPU. When syslog-ng restarts, it starts another audit_forwarder process, but it is the orphaned audit_forwarder process that will consume almost 100% CPU. When syslog-ng is restarted and audit_forwarder does not exit cleanly, the mcpd process will also begin consuming high CPU.

Impact

The audit_forwarder and mcpd processes consume excessive CPU.

Conditions

syslog-ng is stopped manually or sometimes (rarely) during a normal restart of syslog-ng.

Workaround

Stop audit_forwarder manually (kill -9), once the orphaned audit_forwarder process is stopped, mcpd will return to normal CPU consumption.

Fix Information

When syslog-ng is stopped manually (or when expected), audit_forwarder also exits, so the audit_forward process no longer consumes increasing CPU.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips