Managing the number of replication sessions

You can manage the maximum number of sessions that are used for sending data to the target replication server to improve replication performance.

About this task

Use the MAXSESSIONS parameter to specify the maximum number of sessions to use. When you calculate the value for the MAXSESSIONS parameter, consider the available network bandwidth and the processor capacity of source and target replication servers.

Consider the number of logical and physical drives that can be dedicated to the replication process. You must ensure that there are enough drives available for replication processing because other server processes or client sessions might also be using drives. The number of mount points and drives available for replication operations depends on the following factors:
  • Tivoli® Storage Manager server activity that is not related to replication
  • System activity
  • The mount limits of the device classes for the sequential-access storage pools that are involved
  • The availability of a physical drive on the source and target replication servers, if the device type is not FILE
  • The available network bandwidth and the processor capacity of source and target replication servers

Procedure

Issue the REPLICATE NODE command and specify the MAXSESSIONS parameter to determine the number of data sessions. For example, to set the maximum number of replication sessions to 6 for NODE_GROUP1, issue the following command:
replicate node node_group1 maxsessions=6
Restriction: The following values apply to the MAXSESSIONS parameter:
  • The value that is specified by the MAXSESSIONS parameter applies only to data sessions. Data sessions are sessions during which data is sent to a target replication server. If you issue a QUERY SESSION command, the total number of sessions might exceed the number of data sessions. The difference can occur if you use short control sessions that you use to query and set up replication operations.
  • The value of the MAXSESSIONS parameter represents the maximum allowable number of sessions. The number of sessions that are used for replication depends on the amount of data to be replicated. If you are replicating only a small amount of data, there is no advantage to increasing the number of sessions.