Replicating client data to multiple servers

You can replicate data from a source replication server to two target replication servers. The process of creating copies of data and sending the copies to multiple servers is called multi-target replication. Replication of data helps to support disaster recovery and data availability if the source replication server becomes unavailable. The replication operation not only copies the data to the target replication server but also communicates the metadata, such as attributes of the source server nodes and file spaces.

About this task

Multi-target replication requires one source replication server and two target replication servers. After the servers are defined, to schedule multi-target replication, you must define multiple replication storage rules. Replication storage rules are designed for scheduling and automating the replication process. For example, to send data from a source replication server to two target replication servers, you would define two replication storage rules. By defining multiple replication storage rules, you can schedule, configure, and run the rules independently.

When you define a replication storage rule, you must specify the name of the target replication server. You can specify other parameters to define the starting time and maximum duration of the replication process. You can also define subrules for a replication storage rule. Subrules are designed to provide more granularity while defining nodes, file spaces, and the data types to be replicated. When you define a subrule, you must specify the name of the replication storage rule, also referred to as the parent rule. When the replication storage rule runs, client node data is replicated. During subsequent processing of the replication storage rule, only new or changed client node data is replicated.

For users of the REPLICATE NODE command: When you transition from using the REPLICATE NODE command to using replication storage rules, only data that was previously not replicated or has changed is processed when you run the replication storage rules.
Tip: In special circumstances, you can replicate data to three target replication servers. For example, assume that you have two target replication servers and must discontinue using one of the servers. During the transition period, you maintain the two target replication servers and define a new target replication server. You define replication storage rules and subrules to ensure that data is synchronized on the source replication server and the three target replication servers. After the data is synchronized, you can discontinue use of the target replication server that is no longer required.

Procedure

To define a storage rule for replication, follow the instructions in Defining a replication storage rule.