Cluster limits

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The IBM® i system limits for clusters include cluster software limits, and OptiConnect limits.

Table 1. Cluster software limits
Cluster software limits Value
Maximum number of nodes in a cluster 128
Maximum number of nodes in a recovery domain in a cluster resource group 128
Maximum number of clusters that a node may be a member of 1
Maximum number of IP addresses per cluster node 2
Maximum number of data port IP addresses per recovery domain node 4
Maximum number of site names per device cluster resource group 2
Maximum number of configuration objects per cluster resource group1 256 or 200
Maximum number of application restarts 3
Maximum number of monitored resources in a cluster administrative domain Start of change200 000End of change
Notes:
  1. Only 256 configuration objects are allowed in a cluster resource group if TCP/IP addresses are IPv4 format. Only 200 configuration objects are allowed in a cluster resource group if TCP/IP addresses are IPv6 format.
Table 2. OptiConnect (Option 23 of IBM i) limits
OptiConnect limits Value
Maximum number of partitions that can be connected using OptiConnect 64
Maximum number of logical connection paths that can be established between two partitions using OptiConnect 16
Maximum number of OptiConnect open connections between any two partitions using OptiConnect 1 16 382
Maximum total number of active jobs on a partition that can use OptiConnect 1 262 135
Maximum number of TCP/IP subnets per partition that can be configured to use OptiConnect2 8
Notes:
  1. An OptiConnect open connection is an active communications link between a job or task on one partition and a job or task on another partition. Using the WRKOPCACT command, you can determine the number of current open connections by adding the 'Users' count under the Client Statistics View to the Agents count under the Server Statistics View. With this command, you can view the jobs and tasks associated with individual OptiConnect open connections by selecting F14 (Jobs and Tasks). The PRTOPCJOB command could also be used to list OptiConnect jobs and tasks.
  2. The following count as TCP/IP subnets:
    • Each OptiConnect TCP/IP interface with no associated local interface (ADDTCPIFC keyword LCLIFC(*NONE))
    • Each unique interface associated with an OptiConnect TCP/IP interface