The results of which DPA is used Local or other are determined by a few factors.
The number of Maximum sessions set in the DPA. The higher the number of available sessions determines if this resource will be used.
TPAM tracks sessions in use by each resource.
If the DPA is shut off or disconnected. The TPAM may not know this for a period of a time. We have this checked on a time interval that will then put the DPA as unavailable. TPAM polls for this information every 5 minutes.
If shut off the DPA but have Affinity set to 1 for DPA and blank or 2 for LocalServer. We should get a PSM session as long as the TPAM has available session and the period after the shut off has been long enough for TPAM to update the database that the resource is no longer reachable.
Setting the DPA to Not Active in Cluster Management, updates TPAM immediately.