The high queue length in the non-critical queues are less common or less likely to impact customers.
The following are the non-critical queues that can be monitored.
vc_queue_vcmp_init – This queue provides VCMP tunnel initiation messages regarding new tunnel setup. The Gateway throttles incoming tunnel requests to the maximum rate they can be handled without disrupting the existing traffic, based on available cores. As a result, high queue length is expected in the queue on a Gateway with many tunnels.
The packet build up in these queues should come in large bursts following a specific event, like Gateway restart or transit interruption, and there should not be drops during normal operation.
vc_queue_vcmp_ctrl_0 and vc_queue_vcmp_ctrl_1 – This queue provides VCMP tunnel management control messages received on the existing tunnels. This includes messages such as route updates, path state updates, heartbeats, statistics, QoS Sync, and tunnel information.
Almost all control messages have built-in retry mechanisms to account for these drops, like route updates.
vc_queue_ike – The queue processes IKE protocol messages to manage keys and other state of encryption sessions.
This is generally a low volume traffic and it is unlikely that packet build up is encountered here. If drops occur, IKE messages are retried.
