Bug ID 680298: FPS may introduce latency even for unprotected pages

Last Modified: Apr 10, 2019

Bug Tracker

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

Known Affected Versions:
12.1.3, 12.1.2, 12.1.1, 12.1.0, 12.0.0

Opened: Aug 27, 2017
Severity: 3-Major

Symptoms

Depending on TCP profile parameters, FPS may introduce latency even for unprotected pages due to re-chunking of response. The latency introduction may arise when re-chunking causes a small TCP segment that the BIG-IP system's TCP stack or upstream device chooses to buffer (for example, due to Nagle's algorithm)

Impact

FPS unprotected pages may suffer 10's to 100's ms latency

Conditions

1. FPS attached to virtual server. 2. TCP profile parameters (Nagle's Algorithm, MSS, etc.). 3. Chunked response from server.

Workaround

Experience shows that disabling Nagle's Algorithm (for example) might overcome FPS latency, but it should be noted that this sort of mitigation should be carefully examined as it is influenced by many parameters (traffic patterns, other TCP profile parameters, SSL profile, etc.).

Fix Information

None

Behavior Change