Bug ID 1046785: Missing GTM probes when max synchronous probes are exceeded.

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP DNS, GTM(all modules)

Known Affected Versions:,,,, 15.1.3,, 15.1.4,, 15.1.5, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,

Fixed In:
17.0.0,,, 14.1.5, 13.1.5

Opened: Sep 15, 2021

Severity: 3-Major


GTM probes are missing, resources are marked down. When instances fail and BIG-IP is not aware of the failure, some virtual servers/pool members are marked as available and some objects are marked down on part of the sync group members. In the /var/log/gtm file, the following message may be seen: 011ae116:4: The list processing time (x seconds) exceeded the interval value. There may be too many monitor instances configured with a y second interval Note that this message is only logged once when gtmd is restarted, or when monitors are added or removed in the gtm configuration. In 14.1.x and earlier the message will be slightly different: 011ae106:5: The monitor probing frequency has been adjusted because more than 130 synchronous monitors were detected


-- Resources are marked down. -- Inconsistent monitor statuses across BIG-IP DNS systems in a single sync group, with some showing 'big3d: timed out' and others potentially showing a stale up or down status for the same targets. -- Because some monitor instances don't have monitor traffic, if an instance fails, the BIG-IP DNS systems may not be aware of the failure.


Max synchronous probes are exceeded. This value is controlled by the GTM global variable max-synchronous-monitor-requests.


Increase the value of Max Synchronous Monitor Requests: tmsh modify gtm global-settings metrics max-synchronous-monitor-requests value <value - default is 20>

Fix Information

All monitors are now allowed to probe without triggering a failure.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips