Deprecated high availability components removed
In Apama 5.0, high availability components that were deprecated have been removed. This includes the following:
High availability correlators.
Sender, merger, and sender/merger components.
Because you can no longer use high availability correlators, or sender, merger, and sender/merger components, the commands and icons for adding and managing those components have been removed from the Enterprise Management and Monitoring console (EMM).
MIGRATION NOTES
For applications in which it is unacceptable to lose any information, it may be appropriate to use Apama's correlator persistence feature. Correlator persistence automatically stores the state of the correlator runtime on disk. This means that when you stop and restart a correlator, the correlator restores the most recent saved state.
For complete information about Apama's correlator persistence, including how to design applications to use persistence-enabled correlators, how to fine-tune snapshot and recovery behavior, and descriptions of how correlator persistence interacts with other Apama components such as the MemoryStore and correlator plug-ins, see
Using Correlator Persistence.
Briefly, to use correlator persistence, the following steps are needed.
Specify the keyword
persistent before the monitor declaration for each monitor written in EPL that you want to be persistent. For example:
persistent monitor Order {
action onload() {
...
}
}
Optionally, define
onBeginRecovery() and
onConcludeRecovery() actions in your persistent monitors. The correlator executes these actions during the recovery process.
Specify one or more persistence options when you start the correlator. You must always specify the
-P option to enable correlator persistence.
In addition there are several correlator options such as -PsnapshotInterval and -PstoreLocation that can be used to change the correlator's default behavior.
