Symptoms
When using more than 4 BIG-IP devices connected in a device cluster, and adding 2 more devices to the trust domain, the mcpd processes of each device may get into a sync loop. This causes mcpd to reach up to 90% CPU utilization during this time, and causes other control-plane functionality to halt. This state may last 10-20 minutes in some cases, or continuous in other cases.
Impact
High CPU utilization, GUI, TMSH, and REST API not responding or slow-responding, other system processes halted.
Conditions
-- More than 4 BIG-IP devices are configured in a trust domain configuration.
-- Adding at least 2 more devices to the trust domain, one after the other, without waiting for the full sync to complete.
-- ASM, FPS, or DHD (DOS) is provisioned.
Workaround
When adding a BIG-IP device to the trust domain, before adding any other device, wait a few minutes until the sync is complete, and no more sync logs display in /var/log/ltm.
Fix Information
MCPD no longer utilizes high CPU resources when adding simultaneously 4 or more devices to CMI.
