Bug ID 1040573: REST operation takes a long time when two different users perform tasks in parallel

Last Modified: Nov 14, 2023

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

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,

Fixed In:
17.1.1, 15.1.10

Opened: Aug 13, 2021

Severity: 3-Major


A considerable delay is observed when different users attempt to execute multiple REST(iCR) requests in parallel.


BIG-IP system performance is impacted.


Multiple iControl REST operations are performed by different users in parallel. When attempting multiple requests by single or multiple users with and without bulk config , following behaviors are observed: 5 ICRD children getting spawned successfully and same are being observed in logs and noticed that these children are serving multiple rest requests fired by multiple users Observed expected results for all below scenarios, except the last scenario which has a caveat: 1. Verify multiple rest requests fired with single user 2. Verify multiple rest requests fired with multiple users(5 users ) 3. Verify single rest request fired with multiple users (5 users) 4. Verify multiple rest requests fired from multiple users with Bulk config(5 users) 5. Verify single rest request fired from multiple users with Bulk Config(5 users) Scenario5 has a Caveat with the current fix , since this fix limits up to 4 concurrent requests , the connection may be refused for some of the requests if the concurrent requests are more than 4.


Use only one user to process the multiple requests. OR Use an iControl REST transaction containing multiple requests.

Fix Information

Create icrd child per user to avoid context switching. If maxNumChild threshold is reached then allocate users in round robin fashion to all available children to process the requests.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips