Bug ID 760475: Apache spawns more processes than the configured limit, causing system low memory condition

Last Modified: Jul 12, 2023

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

Known Affected Versions:
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

Fixed In:
15.0.0, 14.1.2.1

Opened: Mar 05, 2019

Severity: 2-Critical

Symptoms

Apache (httpd) process count MaxClients on BIG-IP systems is set to '10' in the configuration. When more requests are received, Apache spawns more processes than 10, consuming more memory.

Impact

System low memory condition can severely impact application/system performance, and sometimes triggers Out-Of-Memory (OOM) Killer, so critical applications might be terminated.

Conditions

Numerous clients trying to connect simultaneously to the BIG-IP GUI.

Workaround

Complete the following procedure: 1. Modify /etc/httpd/conf/httpd.conf to have the following configuration outside of the prefork module (global): MaxClients 10 2. Run the following command: bigstart restart httpd

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips