The topology defines the relative location of
a data store and its messaging engine, as well as the relationship
with other data stores.
You
have several options for the relative location of a data store and
its messaging engine. The topology also defines the relationship of
a data store with other data stores.
The following principles apply:
- The default embedded Cloudscape Version 10.1.x (Derby) data
store always runs in the same server process as the messaging engine.
- For a messaging engine that can failover within a WebSphere® cluster, you must ensure that
any server that the policy might choose to run the messaging engine
on can gain access to the data store. The embedded Cloudscape
Version 10.1.x (Derby) data store is not supported for a messaging
engine running in a WebSphere cluster.
Use either Cloudscape Version 10.1.x (Derby) in Network
Attach mode, or an alternative relational database management system.
To support high availability, you can configure the data store
as follows:
- Configure the data store to use a shared, network mounted, file
system. Ensure that you protect against the file system being a single
point of failure.
- Configure the data store to use a remote database server. Ensure
that you protect against a failure of the database server.
- Configure the data store to use a "shared disk" in a high
availability cluster. The high availability cluster performs failover
of the data store and, optionally, can coordinate failover of the
messaging engine .