Configuring an appliance cluster

An email appliance operates in standalone mode by default, but can be configured in a cluster of appliances to manage a large volume of email traffic. After you have added an appliance to the appliances list on the Email Appliances page, you can change its mode from the default standalone to either primary or secondary on the page Settings > General > Cluster Mode.

Some platform limitations apply to appliances in a cluster:

• A V10000 appliance cannot be configured in a cluster with a V5000 appliance.
• A virtual appliance may be clustered with other virtual appliances, but not with a physical appliance.
• Platform versions must match in a cluster.
• Appliances in a cluster should also have the same message queue configurations. Messages in a secondary appliance queue may be lost if that queue is not configured on the primary machine before the cluster is created.
  Note:

  If you are deploying email protection in an appliance cluster and want to use DLP policies, be sure to register all the primary and secondary cluster machines with the Data Security module before you deploy DLP policies.

  If you deploy DLP policies on the primary appliance while you are registering a secondary machine with the Data Security module, the registration process for the secondary machine may not complete.