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h1. On the Petals ESB Registry cluster

The Petals ESB Registry is in charge of storing all service endpoints deployed on several Petals ESB. For a high availability purpose, this registry is a cluster that we must defined.

The Petals ESB Registry cluster can be configured through a cluster definition (ie. {{cluster.xml}}).

This document will explain to you how to properly configure the cluster of your Petals ESB Registry.

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h1. Cluster composition

The Petals ESB Registry cluster is mainly an Hazelcast full TCP/IP cluster. It does not support auto-discovering, it's a static cluster, in which each member is listed.

h1. Configuring the cluster

The cluster configuration is composed of several part:
* credentials to authorize a node to join the cluster,
* the list of member nodes
* the Hazelcast management center

h2. Cluster credentials

To protect the cluster to avoid unauthorized node to join it, you must define credentials:
{code}
<tns:petals-registry-overlay>
<tns:credentials>
<tns:group>default-sample</tns:group>
<tns:password>s3cr3t</tns:password>
</tns:credentials>
...
</tns:petals-registry-overlay>
{code}

All members of the cluster must be listed:
{code}
<tns:petals-registry-overlay>
...
<tns:members>
<!-- Default listening port: 7900 -->
<tns:member id="sample-member-0">localhost</tns:member>
<tns:member id="sample-member-2" port="7902">192.168.1.56</tns:member>
</tns:members>
</tns:petals-registry-overlay>
{code}

h2. Hazelcast Management Center

A Hazelcast Management center can be set at cluster level to monitor your Petals ESB Registry:
{code}
<tns:petals-registry-overlay>
...
<!-- By default, the support of the Hazelcast Management Center is enable -->
<tns:management-console enable="true">http://localhost:8080/mancenter</tns:management-console>
</tns:petals-registry-overlay>
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