Bug ID 752542: Automatic eviction of PEM URLCAT cloud cache

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP AFM, PEM(all modules)

Known Affected Versions:
12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Fixed In:
15.0.0, 14.1.4.4

Opened: Dec 10, 2018

Severity: 3-Major

Symptoms

PEM URLCAT looks up the URL in the local webroot database of 20 million entries. If an entry is not found in the webroot local DB, a message is sent to webroot website. The results from the web lookup are stored in a per tmm local cache, which can hold 128K entries (by default). If the local cache fills up, the cloud query no longer happens. It is required to clear up some space in the cloud cache to accommodate the new entries.

Impact

Cloud query no longer happens for new requests.

Conditions

If the local cache fills up, the cloud query no longer happens.

Workaround

None

Fix Information

10% of the per tmm local cache will be cleared and new entries will be added in this space only. The last 10% of memory will always be cleared if the local cache is full.

Behavior Change

The entries in the cloud cache will be evicted, if the cache becomes full. Prior to this change, the cloud lookup would stop altogether once the cache was full.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips