Bug ID 828937: Some systems can experience periodic high IO wait due to AVR data aggregation

Last Modified: Mar 25, 2020

Bug Tracker

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,,, 13.1.3,,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,,, 14.1.2,,,, 15.0.0, 15.0.1,,, 15.1.0

Opened: Sep 19, 2019
Severity: 2-Critical
Related AskF5 Article:


Systems with a large amount of statistics data collected in the local DB (i.e., systems not working with BIG-IQ) can have high IO Wait CPU usage, peaking at 10 minutes, 1 hour, and 24 hours. This is caused by the data aggregation process that is running on local DB.


High IO can impact various processes on BIG-IP systems. Some of them can experience timeouts and can be restarted.


-- The BIG-IP system is collecting statistics locally (i.e., not sending data to BIG-IQ or another external device). -- There is a large amount of statistics data.


The most effective workaround is to lower the amount of data collected by setting the 'avr.stats.internal.maxentitiespertable' DB variable to a lower value. The recommended values are 20000 (on larger, more powerful systems with more than 16 cores) or 2148 (on smaller systems).

Fix Information


Behavior Change