Bug ID 1047577: System statistics may fail to update, or report negative deltas due to delayed stats merging

Last Modified: Jun 28, 2025

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

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 14.1.5.4, 14.1.5.6, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6

Fixed In:
17.1.0

Opened: Sep 17, 2021

Severity: 3-Major

Symptoms

Under some conditions, the BIG-IP might fail to report statistics over time. This can manifest as statistics reporting unchanging statistics (for example, all zeroes (0)), or as sudden spikes in traffic, or as negative deltas in some counters. The system performance graphs will also appear to have gaps / be missing data at the times that this occurs.

Impact

Statistics fail to merge, which results in incorrect view of system behavior and operation.

Conditions

An iRule is configured which uses SSL::profile.

Workaround

This issue has two workarounds: - Reduce the frequency of changes in the statistics data structures. The specific action to take depends on what is triggering them. To do so, use any or all of the following: -- Reduce the frequency of configuration changes. -- Reduce the use of 'SSL::profile' in iRules. -- Reduce the number/frequency of processes being spawned by the system. or As an alternate, the following is the second workaround which can be implemented in two parts: - Switch statistics roll-ups to the 'slow_merge' method, which causes the system to spend more CPU merging statistics. To do so, set the 'merged.method' DB key to 'slow_merge' using the following command: tmsh modify sys db merged.method value slow_merge or - To reduce CPU usage when merge-method is slow-merge, change the merge-interval value to two using the following command: tmsh modify /sys db merged.merge.interval {value "2"} Note: Performing the second workaround has the drawback of disabling TMSTAT snapshots on the device. The TMSTAT snapshots are intended for F5-internal use only: the lack of snapshots will have no bearing on the functionality of the BIG-IP; however, F5 Support might be impacted in their ability to troubleshoot issues in BIG-IP.

Fix Information

The db variable "defaultlistenerstatrow" when enabled will update the system statistics as expected.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips