Bug ID 1006449: High CPU utilization by mcpd process and slow SNMP response

Last Modified: May 19, 2026

Affected Product(s):
BIG-IP Install/Upgrade, TMOS(all modules)

Known Affected Versions:
14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 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, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 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, 15.1.10.7, 15.1.10.8, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2, 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, 16.1.6.1, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3, 17.1.3.1, 17.1.3.2, 17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5, 17.5.1.6, 21.0.0, 21.0.0.1

Opened: Mar 25, 2021

Severity: 2-Critical

Symptoms

After upgrading BIG-IP to version 14.0.0 or later, CPU utilization increases and SNMP queries take an unusually long time to respond.

Impact

SNMP queries take an unusually long time to return data. The GUI (TMUI) may be less responsive. There may be gaps in system statistics graphs.0 CPU utilization by the mcpd process may be much higher than usual, and typically several times snmpd CPU usage. This usage will shows as higher control plane or odd CPU core (where split planes is in use), and may be more noticeable on devices with less cores. If the mcpd CPU use is very high (near 100%) for a protracted period of time this can lead to system instability.

Conditions

-- SNMP client or clients repeatedly polls BIG-IP for OIDs in multiple tables over a short period of time. -- The above condition may occur after changes in polling pattern by SNMP clients that might occur, for example, after upgrade or reboot of BIG-IP, or restoration of access by SNMP clients to BIG-IP. The polling pattern may also change if the phasing of requests drifts over time across the set of SNMP clients.

Workaround

To the file /config/snmp/bigipTrafficMgmt.conf, add one line with the following content: cacheObj 16 This could be accomplished by executing the following command line from bash: # echo "cacheObj 16" >> /config/snmp/bigipTrafficMgmt.conf After the above config file has been modified and saved, the "snmpd" daemon must be restarted, using one of two command variants: (on a BIG-IP appliance or VE system) # bigstart restart snmpd (on a a multi-slot VIPRION or vCMP guest) # clsh bigstart restart snmpd (However, this adjustment may be lost when the BIG-IP software is next upgraded. This adjustment is retained when upgrading to a version marked as fixed in ID 1602209. )

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips