I am doing some preliminary research on HA failover capabilities on DB2/UDB 8.1. The docs are a little light on details so I thought I'd ask this forum ...
Let say I have a two node cluster (NodeA and NodeB) with each node running its own instance of DB2/UDB (InstanceA and InstanceB) servicing completely different databases and applications. I understand one supported configuration is a "mutual failover" where each node monitors the other and fails over under the right fault conditions.
My question is ... When the NodeA fails, does the original instanceB on NodeB simply "mount" InstanceA's databases and run rollforward recovery on its logs. In other words, when failover occurs, must an entire startup of DB2 occur (including all the costs associated with it such as allocating memory, setting up buffer pools, etc ...)?
Perhaps it depends on the HA software used (HACMP vs Veritas, etc.), but I imagine DB2/UDB needs some capabilities to support failover to an already running instance.