To support the new Queries feature in Apama 5.3, some internal (non-public) event definitions have been changed in ScenarioService.mon. The change will have no effect on most applications as this API is not officially supported or documented. However it may affect customers using a persistent correlator to maintain application state across an upgrade from Apama 5.2 (or earlier) to 5.3 (or later), if they also make use of scenarios, DataViews or the MemoryStore plug-in.

This is because the EPL that is recovered from the persistent store after the upgrade will use the older (pre-5.3) event definitions and these are not compatible with post-5.3 Scenario Service clients and dashboards, or with the MemoryStore plugin. As a result users may see event parsing failures logged by the correlator, and/or Scenario Service clients and dashboards reporting errors such as ScenarioService cannot parse event due to mismatch between the EPL event definition and the ScenarioService client.

In most cases it should still be possible to recover from a pre-5.3 persistent store without losing application state, provided the following actions are taken immediately after starting the correlator post-upgrade: