Bug ID 657531: High memory usage when using the ICAP server

Last Modified: Jul 18, 2026

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

Known Affected Versions:
11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 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, 12.0.0 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, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1

Fixed In:
13.1.0

Opened: Apr 09, 2017

Severity: 3-Major

Related Article: K02310615

Symptoms

High UMU memory when using the ICAP server.

Impact

UMU memory goes up.

Conditions

-- ICAP is in use. -- There are long requests (requests longer than 128 KB) that should get to the ICAP server.

Workaround

-- Decrease the max concurrent long requests. -- Decrease the size for the long requests buffer size. -- Make sure the ICAP server is up and running and responding quickly (the issue will be more visible when the ICAP server is lagging).

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips