XDCR Cloud Deployment

XDCR can be used to replicate data between cloud-deployed clusters.

Cloud-Based Replication

When configuring replication between two or more clusters deployed in the cloud, the following requirements apply:

Use public names and addresses

Public DNS names and IP addresses can be used for cloud-based cluster-nodes. Within the cloud deployment-environment, each public IP address is resolved internally within the cluster, but nevertheless allows external communication.

When using Amazon EC2, make sure that:

  • The public interface is enabled in the instance configuration.

  • Security parameters allow communication to the required ports.

  • The public DNS record exposed by Amazon is used as the reference name.

Configure the cluster with a fixed IP address, and configure the public DNS name according to the recommendations for using Couchbase Server in the cloud.

Use a DNS service

Use a DNS service to identify or register a CNAME that points to the public DNS address of each node within the cluster.

The CNAME will be constant, even though the underlying public DNS address may change within the cloud service. The CNAME record entry can then be used as the destination IP address, when configuring replication between the clusters using XDCR.

If a transient failure causes the public DNS address for a given cluster-node to change, update the CNAME to point to the updated public DNS address provided by the cloud service. When the CNAME records are updated, replication should be able to persist over a public, internet-based connection, even though the individual IP addresses of cluster nodes have been referenced in XDCR configuration.

For additional security, configure security groups to allow traffic only on the required ports between the IP addresses for each cluster. To configure security groups, specify the inbound port and IP address-range. Ensure that the security configuration includes the correct port and IP addresses for the other cluster-nodes, so that communication between them can occur.