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Clusters: Configuration: Migration
Configuration Options Related Tasks Related Topics
If a clustered server fails, Node Manager can automatically restart the server and its services on another machine. This page allows you to specify the machines where Node Manager can restart migratable servers and to specify the data source used during server migration.
Configuration Options
Name Description Candidate Machines For Migratable Servers The set of machines (and order of preference) on which Node Manager will restart failed servers. (Requires you to enable each server for automatic migration.)
Each server can specify a subset of these cluster-wide candidates, which limits the machines on which the server can be restarted. Servers can also specify their own order of preference.
MBean Attribute:
ClusterMBean.CandidateMachinesForMigratableServersChanges take effect after you redeploy the module or restart the server.
Migration Basis Controls the mechanism used for server and service migration.
- Database
-- Requires the availability of a high-availability database, such as Oracle RAC, to store leasing information.
- Consensus
-- Stores the leasing information in-memory within a cluster member. This option requires Node Manager to be configured and running.
Note: Within a WebLogic Server installation, you can only use one type of leasing. Although it is possible to implement multiple features that use leasing within your environment, each must use the same kind of leasing.
MBean Attribute:
ClusterMBean.MigrationBasisChanges take effect after you redeploy the module or restart the server.
Data Source For Automatic Migration The data source used by servers in the cluster during migration. (You must configure each Migratable Server within the cluster to use this data source.)
MBean Attribute:
ClusterMBean.DataSourceForAutomaticMigrationChanges take effect after you redeploy the module or restart the server.
Auto Migration Table Name Return the name of the table to be used for server migration.
MBean Attribute:
ClusterMBean.AutoMigrationTableNameChanges take effect after you redeploy the module or restart the server.
Member Discovery Timeout Gets the MemberDiscoveryTimeout value. This value defines the amount of time a server waits during or after startup to discover members that belong to the same cluster. This information is used to join or form a new cluster.
MBean Attribute:
DatabaseLessLeasingBasisMBean.MemberDiscoveryTimeoutMinimum value:
10Changes take effect after you redeploy the module or restart the server.
Leader Heartbeat Period Gets the LeaderHeartbeatPeriod value. The cluster leader heartbeats a special leader heartbeat every period seconds to publish group view version and other cluster information. Members look at this heartbeat and perform any sync up operations if required.
Minimum value:
1Changes take effect after you redeploy the module or restart the server.
Additional Migration Attempts A migratable server could fail to come up on every possible configured machine. This attribute controls how many further attempts, after the first one, should be tried. Note that each attempt specified here indicates another full circut of migrations amongst all the configured machines. So for a 3-server cluster, and the default value of 3, a total of 9 migrations will be attempted. If it is set to -1, migrations will go on forever until the server starts.
MBean Attribute:
ClusterMBean.AdditionalAutoMigrationAttemptsChanges take effect after you redeploy the module or restart the server.
Pause Time Between Migration Attempts Controls how long of a pause there should be between the migration attempts described in getAdditionalAutoMigrationAttempts(). Note that this delay only happens when the server has failed to come up on every machine.
MBean Attribute:
ClusterMBean.MillisToSleepBetweenAutoMigrationAttemptsChanges take effect after you redeploy the module or restart the server.
