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Domains: Monitoring: Clusters

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Use this page to monitor the runtime status of clusters that are part of the current WebLogic Server domain.

Column Display

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 of

The name that you specified when you created the cluster.

Servers

The servers which have declared membership in this cluster.

MBean Attribute:
ClusterMBean.Servers

Changes take effect after you redeploy the module or restart the server.

Cluster Messaging Mode

Specifies the messaging type used in the cluster.

Multicast messaging, the default, is provided for backwards compatibility.

Unicast message is recommended for new clusters.

MBean Attribute:
ClusterMBean.ClusterMessagingMode

Replication Type

Optimizes cross-cluster replication for the type of network that servers in the clusters use for administrative communication.

To enhance the reliability of HTTP sessions, you can configure servers in one cluster to replicate the session data to servers in a different cluster. In such an environment, configure the clusters to be one of the following types:

  • man

    if the clustered servers can send their data through a metro area network (man) in which latency is negligible. With this ClusterType value, servers replicate session state synchronously and in memory only. For example, when serverA in cluster1 starts an HTTP session, its backup server, serverB in cluster2, immediately replicates this session in memory to Server B.

  • wan

    if the clusters are far apart or send their data through a wide area network (wan) that experiences significant network latency. With this ClusterType value, a server replicates session state synchronously to the backup server in the same cluster and asynchronously to a server in the remote cluster. For example, when serverA in cluster1 starts an HTTP session, it sends the data to serverB in cluster1 and then asynchronously sends data to serverX in cluster 2. ServerX will persist the session state in the database.

    If you persist session data in a replicating database, and if you prefer to use the database to replicate the data instead of WebLogic Server, choose a cluster type of wan and leave the remote cluster address undefined. WebLogic Server saves the session data to the local database and assumes that the database replicates data as needed.

MBean Attribute:
ClusterMBean.ClusterType

Changes 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.MigrationBasis

Changes take effect after you redeploy the module or restart the server.

Default Load Algorithm

The algorithm to be used for load-balancing between replicated services if none is specified for a particular service. The round-robin algorithm cycles through a list of WebLogic Server instances in order. Weight-based load balancing improves on the round-robin algorithm by taking into account a pre-assigned weight for each server. In random load balancing, requests are routed to servers at random.

Defines the algorithm to be used for load-balancing between replicated services if none is specified for a particular service.

MBean Attribute:
ClusterMBean.DefaultLoadAlgorithm

Cluster Broadcast Channel

Specifies the channel used to handle communications within a cluster. If no channel is specified the default channel is used.

ClusterBroadcastChannel is only are supported if the unicast messaging type is used.

MBean Attribute:
ClusterMBean.ClusterBroadcastChannel

Changes take effect after you redeploy the module or restart the server.

Cluster Address

The address that forms a portion of the URL a client uses to connect to this cluster, and that is used for generating EJB handles and entity EJB failover addresses. (This address may be either a DNS host name that maps to multiple IP addresses or a comma-separated list of single address host names or IP addresses.)

Defines the address to be used by clients to connect to this cluster. This address may be either a DNS host name that maps to multiple IP addresses or a comma separated list of single address host names or IP addresses. If network channels are configured, it is possible to set the cluster address on a per channel basis.

MBean Attribute:
ClusterMBean.ClusterAddress

Changes take effect after you redeploy the module or restart the server.

Multicast Address

The multicast address used by cluster members to communicate with each other.

The valid range is from from 224.0.0.0 to 239.255.255.255. The default value used by WebLogic Server is 239.192.0.0. You should avoid using multicast addresses in the range x.0.0.1

This address should be unique to this cluster and should not be shared by other applications.

MBean Attribute:
ClusterMBean.MulticastAddress

Changes take effect after you redeploy the module or restart the server.

Multicast Port

The multicast port (between 1 and 65535) used by cluster members to communicate with each other.

Defines the multicast port used by cluster members to communicate with each other.

MBean Attribute:
ClusterMBean.MulticastPort

Minimum value: 1

Maximum value: 65535

Changes take effect after you redeploy the module or restart the server.

Multicast TTL

The number of network hops (between 1 and 255) that a cluster multicast message is allowed to travel.

Defines the number of network hops that a cluster multicast message is allowed to travel. 1 restricts the cluster to one subnet.

MBean Attribute:
ClusterMBean.MulticastTTL

Minimum value: 1

Maximum value: 255

Changes take effect after you redeploy the module or restart the server.

Multicast Buffer Size

The multicast socket send/receive buffer size (at least 64 kilobytes).

Returns the multicast socket send/receive buffer size.

MBean Attribute:
ClusterMBean.MulticastBufferSize

Minimum value: 64

Changes take effect after you redeploy the module or restart the server.

Multicast Send Delay

The amount of time (between 0 and 250 milliseconds) to delay sending message fragments over multicast in order to avoid OS-level buffer overflow.

Defines the number of milliseconds to delay sending message fragments over multicast in order to avoid OS-level buffer overflow.

MBean Attribute:
ClusterMBean.MulticastSendDelay

Minimum value: 0

Maximum value: 250

Changes take effect after you redeploy the module or restart the server.

Service Age Threshold Seconds

The number of seconds (between 0 and 65534) by which the age of two conflicting services must differ before one is considered older than the other.

Defines the number of seconds by which the age of two conflicting services must differ before one is considered older than the other.

MBean Attribute:
ClusterMBean.ServiceAgeThresholdSeconds

Minimum value: 0

Maximum value: 65534

Client Cert Proxy Enabled

Whether to honor the WL-Proxy-Client-Cert header coming with the request or not.

MBean Attribute:
ClusterMBean.ClientCertProxyEnabled

Changes take effect after you redeploy the module or restart the server.

Weblogic Plugin Enabled

Whether the proprietary WL-Proxy-Client-IP header should be used. (This needed only when WebLogic plugins are configured.)

Gets the weblogicPluginEnabled attribute of the ClusterMBean object

MBean Attribute:
ClusterMBean.WeblogicPluginEnabled

Changes take effect after you redeploy the module or restart the server.

Member Warmup Timeout Seconds

Maximum number of seconds that a cluster member will wait to discover and synchronize with other servers in the cluster. Normally, the member will be able to sync in 30 seconds. If the value of this attribute is higher, that does not necessarily mean that it will take longer for the member to warmup. Instead it defines an upper bound on the time that a server will wait to sync with the servers that it has discoverred. If the value is set 0, servers will not attempt to discover other running server in the cluster during server initialization

MBean Attribute:
ClusterMBean.MemberWarmupTimeoutSeconds

Minimum value: 0

Changes take effect after you redeploy the module or restart the server.

Http Trace Support Enabled

Returns the value of HttpTraceSupportEnabled.

MBean Attribute:
ClusterMBean.HttpTraceSupportEnabled

Changes take effect after you redeploy the module or restart the server.

Frontend Host

The name of the host to which all redirected URLs will be sent.

Sets the HTTP FrontendHost for the default webserver (not virtual hosts) for all the servers in the cluster. Provides a method to ensure that the webapp will always have the correct HOST information, even when the request is coming through a firewall or a proxy. If this parameter is configured, the HOST header will be ignored and the information in this parameter will be used in its place, when constructing the absolute urls for redirects.

MBean Attribute:
ClusterMBean.FrontendHost

Changes take effect after you redeploy the module or restart the server.

Frontend HTTP Port

The name of the HTTP port to which all redirected URLs will be sent.

Sets the FrontendHTTPPort for the default webserver (not virtual hosts) for all the servers in the cluster. Provides a method to ensure that the webapp will always have the correct PORT information, even when the request is coming through a firewall or a proxy. If this parameter is configured, the HOST header will be ignored and the information in this parameter will be used in its place, when constructing the absolute urls for redirects.

MBean Attribute:
ClusterMBean.FrontendHTTPPort

Changes take effect after you redeploy the module or restart the server.

Frontend HTTPS Port

The name of the secure HTTP port to which all redirected URLs will be sent.

Sets the FrontendHTTPSPort for the default webserver (not virtual hosts) for all the servers in the cluster. Provides a method to ensure that the webapp will always have the correct PORT information, even when the request is coming through a firewall or a proxy. If this parameter is configured, the HOST header will be ignored and the information in this parameter will be used in its place, when constructing the absolute urls for redirects.

MBean Attribute:
ClusterMBean.FrontendHTTPSPort

Changes take effect after you redeploy the module or restart the server.

Idle Periods Until Timeout

Maximum number of periods that a cluster member will wait before timing out a member of a cluster.

Maximum number of periods that a cluster member will wait before timing out a member of a cluster.

MBean Attribute:
ClusterMBean.IdlePeriodsUntilTimeout

Minimum value: 3

Changes take effect after you redeploy the module or restart the server.

Remote Cluster Address

Set the foreign cluster. Cluster infrastructure uses this address to connect to foreign cluster for HTTP Session WAN/MAN failover.

MBean Attribute:
ClusterMBean.RemoteClusterAddress

Changes take effect after you redeploy the module or restart the server.

Replication Channel

The channel name to be used for replication traffic. Cluster infrastructure uses this channel to send updates for HTTP sessions and stateful session beans. If none is set then the default channel will be used.

In order for this feature to work, the named channel must exist on all members of the cluster and must be configured to use the same protocol. It is valid for the selected channel to be configured to use a secure protocol.

MBean Attribute:
ClusterMBean.ReplicationChannel

Changes take effect after you redeploy the module or restart the server.

Inter Cluster Comm Link Health Check Interval

If the cluster link between two clusters goes down, a trigger will run to periodically to see if the link is restored. The duration is specified in milliseconds.

MBean Attribute:
ClusterMBean.InterClusterCommLinkHealthCheckInterval

Job Scheduler Table Name

The table name to use for storing timers active with the job scheduler

MBean Attribute:
ClusterMBean.JobSchedulerTableName

Changes take effect after you redeploy the module or restart the server.

Persist Sessions On Shutdown

When shutting down servers, sessions are not updated. If the primary and secondary servers of a session are shut down with no session updates, the session will be lost. Turning on PersistSessionsOnShutdown will save any active sessions to the database specified in ClusterMBean#getDataSourceForSessionPersistence() when a server is shutdown. The sessions will not be written at any other time. (For example, they are not saved via this mechanism if there is a server crash.)

This attribute is applicable both to session persistence on server shutdown or session persistence across a WAN.

Rolling upgrade can potential have a bad interaction with traditional in-memory session replication. As managed servers are shutdown and upgraded, in-memory servlet sessions will be lost if both primary and secondary are rebooted before a new request arrives for the session.

MBean Attribute:
ClusterMBean.PersistSessionsOnShutdown

Changes take effect after you redeploy the module or restart the server.

Session Flush Interval

Interval in seconds until HTTP Sessions are periodically flushed to the backup cluster to dump session state on disk.

MBean Attribute:
ClusterMBean.SessionFlushInterval

Session Flush Threshold

When number of sessions to be flushed reaches this threshold limit, sessions will be flushed to the backup cluster before the flush interval. This helps the server to flush sessions faster under load.

MBean Attribute:
ClusterMBean.SessionFlushThreshold

Health Check Interval Millis

Interval in milliseconds at which Migratable Servers and Cluster Masters prove their liveness via the database.

MBean Attribute:
ClusterMBean.HealthCheckIntervalMillis

Changes take effect after you redeploy the module or restart the server.

Health Check Periods Until Fencing

Maximum number of periods that a cluster member will wait before timing out a Cluster Master and also the maximum number of periods the Cluster Master will wait before timing out a Migratable Server.

MBean Attribute:
ClusterMBean.HealthCheckPeriodsUntilFencing

Minimum value: 2

Changes take effect after you redeploy the module or restart the server.

Fencing Grace Period Millis

During automatic migration, if the Cluster Master determines a server to be dead, it waits for this period of time (in milliseconds) before the Cluster Master migrates the service to another server in the cluster.

MBean Attribute:
ClusterMBean.FencingGracePeriodMillis

Changes take effect after you redeploy the module or restart the server.

Multicast Data Encryption

Enables multicast data to be incrypted. Only the multicast data is encrypted. Multicast header information is not encrypted.

MBean Attribute:
ClusterMBean.MulticastDataEncryption

Changes take effect after you redeploy the module or restart the server.

Additional Auto 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.AdditionalAutoMigrationAttempts

Changes take effect after you redeploy the module or restart the server.

Time To Sleep Between Auto 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.MillisToSleepBetweenAutoMigrationAttempts

Changes take effect after you redeploy the module or restart the server.

Replication Timeout Enabled

Indicates if timeout should be applied to session replication calls.

MBean Attribute:
ClusterMBean.ReplicationTimeoutEnabled

Changes take effect after you redeploy the module or restart the server.

Unicast Discovery Period Millis

The timer period that determines how often other members in the cluster are discovered in unicast messaging scheme. This is not applicable to multicast mode. It applies only to unicast mode.

Minimum value: 1000

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