Bug ID 663063: Disabling pool member used in busy HSL TCP destination can result service disruption.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 12.1.2, 12.1.3, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3

Fixed In:
13.1.0, 13.0.1, 12.1.3.1

Opened: May 04, 2017

Severity: 3-Major

Symptoms

Manually disabling an otherwise available pool member from a pool used as HSL TCP destination can result in tmm crash and service disruption. This is more likely to occur when HSL destination is using 'balanced' distribution.

Impact

Service disruption while tmm recovers. HA fail-over event. Traffic disrupted while tmm restarts.

Conditions

-- Busy HSL destination configured with TCP protocol, balanced distribution, and using pool. -- Manually disabling a pool member.

Workaround

You can avoid the issue in either of these ways: -- Do not manually disable busy pool members that can still respond to TCP handshake. -- Disable the service on the pool member first.

Fix Information

TMM crash no longer occurs when HSL TCP pool member with pending connection is manually disabled.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips