The heap size setting directly relates to how many dynamic clusters are supported on a server. You might need to modify this setting based on your environment configuration. Modifying your heap size can affect application placement as well as health management function.
total RAM / 2 / number of servers = maximum heap
For example, to support three servers on a machine with 1.5 GB of RAM, each dynamic cluster must be 750 MB. Use a maximum heap size of 250 MB to support three servers on that single machine (1500 MB / 2 = / 3 servers = 250 MB). The following table contains some maximum heap size samples.
WebSphere Extended Deployment Server total RAM in GB | Number of supported servers | Dynamic cluster size in MB | Approximate maximum heap size in MB |
---|---|---|---|
1.5 | 1 | Less than 750 | 750 |
1.5 | 2 | Less than 750 | 375 |
1.5 | 3 | Less than 750 | 250 |
2 | 1 | Less than 1000 | 1000 |
2 | 2 | Less than 1000 | 500 |
2 | 3 | Less than 1000 | 333 |
The following steps outline the process for modifying the heap size on a dynamic cluster, which is a fundamental component of the WebSphere Extended Deployment dynamic capabilities.