Bug ID 636044: Large number of glob patterns affects custom category lookup performance

Last Modified: Oct 01, 2018

Bug Tracker

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

Known Affected Versions:
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, 13.0.0

Fixed In:
13.1.0, 13.0.0 HF1, 12.1.2 HF1

Opened: Dec 28, 2016
Severity: 2-Critical
Related AskF5 Article:
K68018520

Symptoms

The number of glob patterns in a custom category linearly affects custom category lookup compute times. For example, twice as many glob patterns will roughly double the CPU resources required to compute a match.

Impact

Slow response times to HTTP requests.

Conditions

A large number of custom category glob patterns. The precise number is not so important as the observed effect of slow response times. However, more than 1000 glob patterns is known to cause a significant observed performance degradation.

Workaround

It may be possible to compress the large collection of glob patterns into fewer patterns.

Fix Information

Glob pattern matching has been extended to be context sensitive. If the pattern includes the marker "://", a glob immediately before it is restricted to the scheme, and a glob immediately after it is restricted to the hostname. If the match can be satisfied with prefix matching, the pattern will be processed with a prefix comparison rather than as a glob. Also, multiple glob patterns are combined together to create a more optimal match pattern. If custom categories patterns use the context sensitive feature, custom category lookup will be optimized.

Behavior Change