Replication configuration

Configuring content replication involves one or more storage device connections and an advanced storage area. How you set the following configuration options determines how an advanced storage area prioritizes content uploads to replicas.

A storage device connection associates a single storage device replica to an advanced storage area. The same replica can be associated with more than one storage device connection. By associating different storage device connections to the same storage device, you can share the storage device between multiple advanced storage areas within the same object store.

You must set one of the following replication synchronization types on a storage device connection:

  • Primary: Replicas of this type are selected first for uploading content to an advanced storage area.
  • Secondary: If the desired number of synchronous replicas has not been met, then secondary replicas are selected to upload content.
  • Asynchronous: Content upload is driven by a replication request sweep.

A storage device connection also allows the synchronization type for the device to be adjusted based on the advanced storage area (ASA) it is connected to or the site it is being accessed from. For example, a connection to ASA-1 has a synchronization type of primary, and a connection to ASA-2 has a synchronization type of asynchronous. Because both connections are associated with the same storage device, that storage device has two replication synchronization roles, primary in ASA-1 and asynchronous in ASA-2.

On an advanced storage area, you set the following replication configuration options:

  • List of storage device connections: Multiple storage device connections can be associated with an advanced storage area. Content is uploaded to all the replicas set on the connections, either synchronously or asynchronously.
  • Required number of synchronous replicas: The minimum number of replicas to which content must be written synchronously during upload. If content cannot be uploaded synchronously to the required number of replicas, the upload fails.
  • Desired number of synchronous replicas: The number of replicas to which you prefer that content be written synchronously during upload. Unless one of the primary or secondary replicas for an advanced storage area fails, content is always synchronously uploaded to this number of replicas.