Bug ID 435947: When some dynamic content is revalidated WAM may stop applying an Etag header

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP AAM, WAM(all modules)

Known Affected Versions:
11.3.0, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 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

Opened: Oct 30, 2013

Severity: 3-Major

Symptoms

Upon WAM cache lifetime expiry, when revalidating content cached in tmm memory and receiving a 304 Not Modified response from OWS, WAM sometimes serves a response with S code 10232 (as expected) but lacking an Etag, and indicates the response came from datastor, when there is no indication of the reason this occurred.

Impact

Without an Etag sent back to the client, WAM might get unnecessary load from clients that otherwise could perform a conditional GET with the Etag.

Conditions

WAM is configured to cache compressed static content from OWS, and OWS does not send a Last-Modified date header in the response.

Workaround

Configure OWS to return the Last-Modified header for content it serves.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips