Bug ID 540949: LB::select command does not work on CMP systems in an iRule that requires asynchronous persistence lookup.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
10.2.4, 11.0.0, 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, 11.5.1 HF1, 11.6.1 HF1, 11.5.1 HF2, 11.6.1 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, 11.6.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.1.0, 11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 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, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.1.0

Opened: Aug 20, 2015

Severity: 3-Major

Symptoms

The LB::select command is not CMP-aware in that if an asynchronous persistence lookup is required, the iRule is suspended, then when the persist reply shows up, the proxies (both TCP and MBLB) either drop it, or apply it to the incorrect context.

Impact

The iRule then stays suspended until the flow is torn down. Connections intermittently hang in LB::select.

Conditions

LB::select command does not work on CMP systems (that is, more than one TMM) in an iRule that requires asynchronous persistence lookup.

Workaround

Use the pool command to specifically load balance.

Fix Information

LB::select is no longer visible in tab-completion help, so the issue of the command not working on CMP systems is no longer relevant.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips