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Before data replication policies are configured with SyncIQ, mapping out how policies align with IT administration requirements is recommended. Data replication between clusters is configured based on either entire cluster replication or directory-based replication. Designing the policy to align with departmental requirements ensures that policies satisfy requirements at the onset, minimizing policy reconfiguration. When creating policies, Disaster Recovery (DR) plans must be considered. DR readiness is a key factor to success during a DR event.
Failover and failback are specific to a policy. If a DR event occurs, failing over several policies would require additional time. On the contrary, if entire cluster replication is configured, only a single policy is failed over, minimizing downtime. Also consider that clients must be redirected to the target cluster manually, through either a DNS update or by manual advisement. If entire cluster replication is configured, a single DNS name change will minimize impacts. However, DR steps may not be a concern if Superna Eyeglass, described in Superna Eyeglass DR Edition, is used.
As policies are created for new departments, consider policy overlap. Although the overlap does not affect the policy running, the concerns include managing many cumbersome policies and resource consumption. If the directory structure in policies overlaps, data is being replicated multiple times, affecting cluster and network resources. During a failover, time is a critical asset. Minimizing the number of policies allows administrators to focus on other failover activities during an actual DR event. In addition, RPO times may be affected by overlapping policies.
During the policy configuration stage, select options that have been tested in a lab environment. For example, for a synchronize policy that is configured to run any time the source is modified, consider the time delay for the policy to run. If the delay is set to zero, every time a client modifies the dataset, a replication job is triggered. Although this setting may be required to meet RPO and RTO requirements, administrators must consider if the cluster resources and network bandwidth can meet the aggressive replication policy. Therefore, test the configuration in a lab environment to ensure that the replication policy requirements are satisfied. Superna Eyeglass, explained in Superna Eyeglass DR Edition, provides additional insight into expected RPO and RTO times, based on a policy.