The PowerExchange Agent caches capture registrations in-storage. Caching capture registrations in-storage enables the PowerExchange Agent to respond as quickly as possible to registration check requests from ECCRs.

By default, the PowerExchange Agent obtains new capture registrations from the PowerExchange Listener and stores the capture registrations in two sequential cache data sets. During startup, the PowerExchange Agent reads the cache data sets to populate the in-storage cache of capture registrations. Then the PowerExchange Agent contacts the PowerExchange Listener and requests all capture registrations. The PowerExchange Agent adds new capture registrations to the in-storage cache and to the cache data sets.

If the PowerExchange Listener is temporarily unavailable for any reason when a real-time system is started, this could cause a problem. The mechanism designed to resolve such a problem involves the use of locally held information stored in two physical sequential data sets to provide resilience. These data sets are refreshed at an interval determined when the installation is configured. You can alter the frequency by changing the UpdateInterval parameter. After any new registrations have been successfully saved into the cache data sets the agent uses them to answer capture queries. If there is any problem obtaining or saving new registrations, the current registrations continue to be used.