Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS
coregroupsplit.py script
You can use thecoregroupsplit.py script to split your existing cell into multiple core groups. Consider running this script if you have more than 40 WebSphere® Application Server related processes such as application servers, node agents, and on demand routers defined in your core group.
Purpose
The coregroupsplit.py script is available with V6.1.0.1 and later. The coregroupsplit.py script divides your existing cell into multiple core groups. If a server changes its core group membership, then restart the entire cell to prevent partitions from forming. For this reason, this default script options for script do not change the core group membership of servers that are members of any core groups other than the DefaultCoreGroup core group.This script tries to satisfy the following best practices for core groups:
This script also tunes the high availability manager for optimum performance. By default, the script configures a core group bridge on each node agent in the cell. The script increases the number of core groups until it reaches the optimal level, depending on the number of nodes and servers in the cell. The core group bridge node agents are configured as a part of the DefaultAccessPointGroup access point group in a mesh topology.
- Each core group must have fewer than 40 servers. This best practice is possible only when you have an adequate ratio of nodes to servers in your cell.
- Each core group must be equipped with at least three core group bridges. This best practice is possible only when you have an adequate ratio of nodes to servers in your cell.
- Each cluster must remain fully mapped to a single core group.
- If you use the -createbridges parameter, the core group bridges and coordinators are preferably hosted on otherwise idle nodes.
Remember that give core group bridges at least 512 MB of Java™ virtual machine (JVM) space.
Location
The coregroupsplit.py script is located in the install_root/bin directory.
Usage
The default script usage follows:./wsadmin.sh -lang jython -f coregroupsplit.pyRunning this script might result in unbalanced core groups, in which some core groups are loaded more or less than other core groups. You can rerun this script to rebalance core group membership, but in this case restart the entire cell for the changes to take effect. To rerun the script, use the following command:./wsadmin.sh -lang jython -f coregroupsplit.py -reconfig
Parameters
- -reconfig
- Performs a full reconfiguration to rebalance the distribution of servers among the core groups.
- -linked
- Creates a ring topology of core group bridges.
- -createbridges
- Creates separate core group bridge processes instead of creating the bridge in the node agent.
- -numcoregroups
- Number of core groups to create.
- -datastacksize
- Specifies a number of megabytes that overrides the default data stack size.
- -proxycoregroup
- Places the on demand routers (ODR) and proxy servers in a separate core group.
- -odrcoregroup
- Places the on demand routers (ODR) and proxy servers in a separate core group.
Example
The following example results in a linked topology where the core group bridges are connected in a ring:./wsadmin.sh -lang jython coregroupsplit.py -linkedYou can also use this script to create static cluster that are dedicated as core group bridges for communication within the core group. Use the following example:./wsadmin.sh -lang jython coregroupsplit.py -createbridges
Related concepts
Dynamic clusters
Related tasks
Creating dynamic clusters
Configure communication between core groups that are in the same cell
Configure WebSphere Virtual Enterprise for cross-cell communication