To replicate table DML operations to a remote WAN site, you
specify one or more named gateway senders when you create the table, or after
you create a table (using the ALTER TABLE statement). The gateway senders that
you specify then replicate the DML operations to the remote GemFire XD clusters
for which they are configured.
A table must have identical column definitions in each cluster in order for GemFire XD to
replicate it between clusters. Use the same DDL command in each cluster to create the
table. If you achieve identical column definitions using different DDL commands (for
example, by using ALTER TABLE to change one table to match another), then you may need
to use SYS.INCREMENT_TABLE_VERSION
to ensure that both tables have the same version in
- Use the GATEWAYSENDER clause with the CREATE TABLE statement to specify one or more
gateway senders. For example, to create a WAN-replicated table in cluster 1
shown in Figure 2:
CREATE TABLE test_table (ID INT NOT NULL, NAME VARCHAR(10))
GATEWAYSENDER(cluster-2-sender, cluster-3-sender) SERVER GROUPS (primary_sender_group, secondary_sender_group)
Note: You can configure both partitioned tables and replicated tables to use a
gateway sender. However, you must use the SERVER GROUPS clause in CREATE
TABLE to a host a replicated table's data in the same server groups that
host the gateway sender(s).
Create and Start Gateway Sender provides more
information about configuring gateway senders.
- Alternatively, use the
statement after you have created a table to add or remove gateway sender
configurations. For example, if you did not supply a GATEWAYSENDER clause in
the CREATE TABLE statement, you could add it later:
ALTER TABLE test_table SET GATEWAYSENDER (cluster-2-sender, cluster-3-sender);
- Repeat these steps to
create the same table definitions in each GemFire XD cluster that will replicate
DML operations for those tables. The WAN replication process does not
automatically create a table in the target GemFire XD cluster.