Bug ID 869081: On large configurations with many CPU cores, merged consumes excessive processor time

Last Modified: Jan 20, 2023

Bug Tracker

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

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,, 15.0.0, 15.0.1,,,,, 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,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,

Opened: Jan 14, 2020
Severity: 3-Major


Measurements of control-plane CPU usage indicate that the merged daemon is dominating the usage of odd-numbered CPU cores.


-- Heavy CPU use by merged may impair all other control-plane operations, even the mcpd process. -- Slow response of command-line and GUI user interfaces may be observed. -- Timeouts occur in response to REST API invocations. -- Attempts to generate qkview datasets may fail.


-- Large configuration, with thousands of defined config elements. -- Platform with large number of CPU cores (greater than 20) supporting many tmm processes.


-- To lessen the impact of the effect, perform both of the following: + Allocate additional memory for use by the control plane: # tmsh modify sys db provision.extramb value 2048 + Increase the time interval between merges from 1 second to 2. -- To discover the merge interval in use, run this command line from bash: # tmsh list sys db merged.merge.interval + If the output value is '1', you can double it: # tmsh modify sys db merged.merge.interval value 2

Fix Information


Behavior Change