Bug ID 575609: Zlib accelerated compression can result in a dropped flow.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.1 HF1, 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, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 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, 11.6.1 HF1, 11.5.4 HF2

Opened: Feb 23, 2016

Severity: 2-Critical

Symptoms

Some compression requests would fail when the estimated compression output block was too small. Such errors deposit an error in the log similar to: Device error: n3-compress0 Zip engine ctx eviction (comp_code=2): ctx dropped.

Impact

The flow that encounters the error is dropped.

Conditions

A block that will not compress can generate a compression output that exceeds the estimated output block size.

Workaround

Disable hardware accelerated compression.

Fix Information

Difficult to compress requests may be dropped.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips