Because the Parsing Engine (PE) and Access Module Processor (AMP) are vprocs and, therefore, software entities, they can migrate from their home node to another node within the same hardware clique if the home node fails for any reason. Although the system normally determines which vprocs migrate to which nodes, a user can configure preferred migratory destinations.
Vproc migration permits the system to function completely during a node failure, with some degradation of performance due to the non-functional hardware.
The following figure illustrates vproc migration, where the large X indicates a failed node, and arrows pointing to nodes still running indicate the migration of AMP3, AMP4, and PE2.
PEs that manage TPA-hosted physical channel connections cannot migrate during a node failure because they are dependent on the hardware that is physically attached to their assigned node.