Bug ID 604926: The TMM may become unresponsive when using SessionDB data larger than ~400K

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 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, 11.5.10, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 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

Fixed In:
13.0.0, 12.1.3, 11.6.3

Opened: Jul 14, 2016
Severity: 2-Critical
Related AskF5 Article:
K50041125

Symptoms

There is a hard limit on messages sizes sent on the backplane on chassis platforms. Messages larger than the limit (~400K) are refused from being sent at a lower layer but buffered for resending at a higher layer. The messages are never sent which cases backplane communication to lockup.

Impact

The TMM becomes unresponsive to client traffic. If left running under load, the TMM might run out of memory from buffering SessionDB data and crash.

Conditions

-- The BIG-IP system is a chassis with more than one blade. -- Client traffic triggers the creation of SessionDB data larger than ~400K.

Workaround

The workaround is the avoid sending large SessionDB data. The TMM may be restarted in the event it does become unresponsive.

Fix Information

There is no longer a hard limit for sending SessionDB data on the backplane.

Behavior Change