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. Although the system typically determines which vprocs migrate to which nodes, you can configure preferred migratory destinations.
Vproc migration enables the system to function completely during a node failure, with some degradation of performance due to the nonfunctional hardware.
The following figure shows vproc migration. 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 depend on the hardware that is physically attached to their assigned node.