Clusters: Configuration: Singleton Services
Column Display Related Tasks Related Topics
This page lists the singleton services that are configured to migrate automatically within this cluster. You can use this page to add or remove singleton services from a cluster.
Automatic service migration allows the automatic health monitoring and migration of singleton services. A singleton service is a service operating within a cluster that is available on only one server at any given time. When a migratable service fails or become unavailable for any reason it is deactivated at its current location and activated on a new server.
If the migration of a singleton service fails on every candidate server within the cluster, the service is left deactivated. You can configure the number of times the number of times the migration master will iterate through the servers in the cluster.
You can show fewer or additional data points on this page by expanding Customize this table and modifying the Column Display list. Each data point displays in its own table column.
The following table lists all of the data points that you can display in columns on this page.
Name Description Name
The name of this singleton service.
The fully qualified name of a class to load and run. The class must be on the server's classpath.
Returns the cluster this singleton service is associated with.
Returns the name of the server that currently hosts the singleton service.
Returns the server that the user prefers the singleton service to be active on.
Return a list of servers that are candiates to host the services deployed to this migratable target. If the ConstrainedCandidateServer list is empty, all servers in the cluster are returned. If the ConstrainedCandidateServer is not empty those servers only will be returned. The user preferred server will be the first element in the list returned.
Constrained Candidate Servers
Returns the (user restricted) list of servers that may host the migratable target. The target will not be allowed to migrate to a server that is not in the returned list of servers. This feature is used to e.g. configure the two server that have acceess to a dual ported disk. All servers in this list must be part of the cluster that is associated with the migratable target.
- Define a New Singleton Service
- Configure a Singleton Service
- Configure clusters
- Configure JDBC data sources