Bug ID 666595: Monitor node log fd leak by bigd instances not actively monitoring node

Last Modified: Dec 20, 2018

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 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, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
13.1.0, 12.1.4

Opened: May 25, 2017
Severity: 3-Major

Symptoms

Each instance of bigd running on the BIG-IP appliance or on each blade in a VIPRION chassis opens a file descriptor for each node or pool member that has monitor logging enabled. However, only one instance of bigd is actively monitoring each individual node, and actively logging health monitor events to the node log. When LTM health monitors are configured with node logging enabled, the bigd daemon may leak file descriptors for the node logs when the monitor is removed from the LTM node, pool, or pool member configuration. Note: This problem does not occur if node logging is disabled in the LTM node or pool member configuration ('logging' value set to 'disabled' in the LTM node or pool member configuration) prior to removing the monitor from the LTM node, pool or pool member configuration.

Impact

When this problem occurs, the instance of bigd that is actively monitoring a particular node will close its file descriptor to that node's log file (under /var/log/monitors), but other instances of bigd running on the BIG-IP appliance or on each blade in a VIPRION chassis will leak their file descriptor to the node log. File descriptors that are opened by the bigd daemon and not closed will count against bigd's internal file descriptor limit. This may result in file descriptor exhaustion and failure of LTM health monitoring.

Conditions

This may occur when the following conditions are met: 1. An LTM health monitor is assigned to an LTM node, pool or pool member with node logging enabled ('logging' value set to 'enabled' in the LTM node or pool member configuration). 2. The LTM health monitor is removed from the LTM node, pool or pool member configuration while logging is still enabled ('monitor' value set to 'none').

Workaround

Disable node logging (set 'logging' value to 'disabled') in the LTM node or pool member configuration prior to removing the monitor from the LTM node, pool, or pool member configuration.

Fix Information

The bigd daemon no longer leaks file descriptors for monitor node logs when multiple instances of bigd are running, LTM health monitors are configured with node logging enabled, and the monitor is then removed from the LTM node, pool, or pool member configuration.

Behavior Change