> # Coherence Clusters

> Column Display Related Tasks Related Topics

> Coherence provides replicated and distributed data management and caching services that you can use to reliably make an application's objects and data available to all servers in a Coherence cluster. To do this, WebLogic Server retains configuration information used to locate and communicate with a Coherence cluster.

> This page displays the Coherence cluster configurations that have been created in this 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 | Name of this Coherence cluster configuration.
> Custom Configuration File | The name of a custom Coherence operational configuration override file. MBean Attribute: `WeblogicCoherenceBean.CustomClusterConfigurationFileName` Changes take effect after you redeploy the module or restart the server.
> Clustering Mode | Specifies a clustering mode of either Unicast or Multicast. If multicast is undesirable or unavailable in an environment, or when an environment is not properly configured to support multicast, then setting up the Well Known Addresses (WKA) feature is required. All cluster multicast communication is disabled if WKA is enabled.

> MBean Attribute:
> `CoherenceClusterParamsBean.ClusteringMode`

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

> Transport | Specify the underlying transport protocol to use for cluster communication. TMB, SDMB, or IMB are only applicable to Exalogic environment. MBean Attribute: `CoherenceClusterParamsBean.Transport` Changes take effect after you redeploy the module or restart the server.
> Security Framework Enabled | Check if security framework is enabled MBean Attribute: `CoherenceClusterParamsBean.SecurityFrameworkEnabled` Changes take effect after you redeploy the module or restart the server.
> Cluster Listen Port | The cluster listen port used by Coherence; Coherence cluster members use this port to discover and join, or create the cluster. If unspecified, the Coherence cluster multicast listen port will be used. MBean Attribute: `CoherenceClusterParamsBean.ClusterListenPort`

> Minimum value: `0`

> Maximum value: `65535`

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

> Multicast Listen Address | The IP address for the cluster multicast listener. MBean Attribute: `CoherenceClusterParamsBean.MulticastListenAddress` Changes take effect after you redeploy the module or restart the server.
> Time To Live | Sets the time-to-live (TTL) setting for the multicast message. The TTL setting designates how far multicast UDP/IP packets can travel on a network. The TTL is expressed in terms of how many hops a packet survives; each network interface, router, and managed switch is considered one hop. The TTL value should be set to the lowest integer value that works. Setting the value too high can use unnecessary bandwidth on other LAN segments and can even cause the operating system or network devices to disable multicast traffic.

> Typically, setting the TTL value to 1 works on a simple switched backbone. A value of 2 or more may be required on an advanced backbone with intelligent switching. A value of 0 is used for single server clusters that are used for development and testing.

> MBean Attribute:
> `CoherenceClusterParamsBean.TimeToLive`

> Minimum value: `0`

> Maximum value: `255`

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

> Logging Enabled | Specifies whether custom Coherence logging is enabled. MBean Attribute: `CoherenceLoggingParamsBean.Enabled` Changes take effect after you redeploy the module or restart the server.
> Members | Servers and clusters on which this Coherence cluster configuration is associated with.

> Related Tasks

> - Create Coherence clusters
> - Configure Coherence clusters
> - Import a custom cluster configuration
> - Configure Coherence logging

> Related Topics

> - Deploying Coherence Applications in WebLogic Server
> - Configuring and Managing Coherence Clusters