Node groups and dynamic clusters are fundamental building blocks
of the dynamic operations environment. Node groups must be created to provide
the functional basis of the WebSphere® Extended Deployment dynamic operations
environment. This task describes how to create a node group or
edit an existing node group. After completing this task, you can create a
dynamic cluster and associate it with this node group.
Before you begin
You must be familiar with the concept of a node group and understand
the attributes, such as grouping together nodes with a common characteristic,
and associating node groups and dynamic clusters to support the on-demand
mode for WebSphere Extended
Deployment, called dynamic operations. You must understand what common properties
your node group contains and how this can be exploited in your infrastructure.
WebSphere Extended
Deployment must be installed and you need access to its administrative console.
Depending
on your administrative role, you are allowed specific privileges when managing
nodes. The following list shows the administrative roles and privileges for
managing nodes:
- Monitor
- Can view the information.
- Operator
- Can set and unset maintenance nodes.
- Can synchronize nodes.
- Can stop nodes.
- Configurator
- Can view the configuration.
- Can add and remove nodes.
- Administrator
- Has all privileges.
About this task
For basic dynamic operations, define a node group specifically for
nodes that are running dynamic clusters. Do not run the ODR on a node that
is a part of this node group.
Procedure
- From the administrative console, click System administration
> Node groups. You can select an existing node group for editing, or click New to
create a new node group.
By default the DefaultNodeGroup
node group is created during installation of WebSphere Extended Deployment. You
cannot modify this node group; it is used by configuration options that are
run at installation to create your system. You can place your ODR nodes in
the DefaultNodeGroup.
If you create a new node group, ensure that you
use a good naming schema and completing the description field with easily
recognizable descriptions. For example, in a large scale environment, create
a naming schema that supports immediate recognition, and use a prefix to ensure
that nodes stand out.
Click OK.
- Add or remove nodes from the node group.
Search for
the node by clicking on the available node groups. Select the local topology
tab to view the node associations per node group. To
get a visual perspective of all of the nodes in a given node group, use the
runtime map. For more information about the runtime map, see The runtime map environment
.
Click Apply or OK to
keep your changes.
- Optional: If you intend to implement dynamic clusters,
you can do the following to override default member behavior before creating
the dynamic cluster. By default, the dynamic cluster member GenerateUniquePorts value
is set to True for the first dynamic cluster member, while
subsequent members are set to False for the z/OS® operating
system nodes and to True for the distributed nodes.
Override this behavior by doing the following:
- Click System administration > Node groups > node_name >
Custom Properties.
- Set GenerateUniquePorts to True or False,
as needed.
- Additionally, you can override this behavior at the node level by setting
the node group's Custom Properties GenerateUniquePorts.nodename to True or False,
as needed.
Optional: To implement vertical stacking,
click System administration > Node groups > nodename > Custom Properties and
set the GenerateUniquePorts value to True to
permit all the dynamic cluster member instances to start successfully on the
same node. Without this setting, only one instance can start and the rest
cannot start on the same node because of a port conflict.
Results
You have now created or edited a node group.
What to do next
After you create the node group, you can perform the following tasks:
- Add members to the node group by creating new nodes. See Managing nodes
for
more information.
- Create dynamic clusters. See Creating dynamic clusters
for
more information.
- Automate the task of adding and removing node group members by using scripting.
See NodeGroupProcs.jacl
for more information.
- Create and configure the on demand router (ODR). See Creating ODRs
for
more information.