If a program or service can be configured as a cluster resource, it is considered cluster-able. A
cluster-aware program simply listens to the cluster service; a cluster-able program interacts with the
cluster service. You can configure cluster-able services as cluster resources, which have individual settings
that indicate how they react during cluster events. For example, you can set how often a resource
polls the active node to see if its counterpart is running, or whether the resource should attempt to fail
back automatically if its home node comes online again.
While there is a generic resource type for use with custom applications, you can code a program
or service to be either cluster-aware (just able to listen to cluster events and react) or cluster-able (able
to interact directly with the cluster itself). If you??™re developing an application to run in a cluster environment,
keep this in mind. (Explaining how to code the service is well beyond the scope of this book.) If a
third-party vendor says that his application works with a cluster, clarify whether he means clusteraware
or cluster-able.
Pages:
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352