Dynamic cluster settings
Use this page to view configurations of existing dynamic clusters.
To view this administrative console page, click Servers > Dynamic clusters
> dynamic_cluster_name.
You must have monitor privileges to view the configuration
of existing dynamic clusters.
- Name
Specifies a name for the dynamic cluster. The name for a dynamic
cluster must be unique among all the clusters in the cell.
The name field cannot contain the following characters: #
\ / , : ; " * ? < > | = + & % ' .
The name cannot begin with a period (.) or a
space. A space does not generate an error, but leading and trailing spaces
are automatically deleted.
- Type
Specifies the type of servers that are being used in the dynamic
cluster.
The following list contains the server types:
- WebSphere Application Server
- Specifies that the dynamic cluster contains application servers that are
running WebSphere Application Server or WebSphere Extended Deployment.
- Apache server
- Specifies that the dynamic cluster contains Apache servers.
- Custom HTTP server
- Specifies that the dynamic cluster contains HTTP servers.
- JBoss server
- Specifies that the dynamic cluster contains servers that are running JBoss
Application Server.
- PHP server
- Specifies that the dynamic cluster contains servers that are running PHP.
- Apache Tomcat server
- Specifies that the dynamic cluster contains servers that are running Apache
Tomcat.
- WebSphere Application Server Community Edition server
- Specifies that the dynamic cluster contains servers that are running WebSphere
Application Server Community Edition.
- BEA WebLogic server
- Specifies that the dynamic cluster contains servers that are running BEA
WebLogic.
- External WebSphere Application Servers
- Specifies that the dynamic cluster contains servers that are in other
cells. These cells might be running other versions of WebSphere Application
Server, such as Version 5.1 or 6.0. You can map these static clusters to a
dynamic cluster.
- Number of running instances
Specifies an automatically generated value that is based on the
number of server instances that are running for the dynamic cluster.
For example, a dynamic cluster might have three applications running, with
two instances running on each of the four members of the dynamic cluster.
The number of instances is 8.
- Operational mode
Specifies the level that the dynamic cluster interacts with the
dynamic operations environment:
- Manual: In manual mode, the dynamic cluster is no different than
the normal application server environments with static clusters. No interaction
with the dynamic operations environment occurs.
- Supervised: In supervised mode, the WebSphere Extended Deployment
environment provides information and recommendations for actions that the
administrator can use.
- Automatic: In automatic mode, the WebSphere Extended Deployment
environment takes actions automatically. In automatic mode, the dynamic operations
environment handles placements and provisioning.
You can change the operational mode in the administrative console by clicking Servers
> Dynamic clusters.
- Enable failover of transaction log recovery
Specifies that for the transaction service component, failover
of the transaction log for recovery purposes is enabled or disabled. This
field is valid for WebSphere application server dynamic clusters only.
The default is disabled. If you enable this setting, the transaction service
properties that are required for peer recovery of failed applications must
be properly configured. If these properties are configured, failover recovery
of the transaction log occurs if the server processing the transaction log
fails. If the transaction services properties that are required for peer recovery
of failed application servers in a cluster are not properly configured, this
setting is ignored.
- Membership policy
Specifies an expression that is used to define which nodes are
used for the dynamic cluster. This option displays only if you choose to automatically
define cluster members with rules. This option does not display if you choose
to manually define your cluster members.
Use the subexpression builder to
build a Membership policy. The membership policy specifies which nodes
are members of the dynamic cluster. Click Preview membership to view
which nodes are in the dynamic cluster with the membership policy that you
defined.
Example
- To define membership as all nodes in a specific node group:
node_nodegroup = 'my_node_group'
- To define membership as all nodes that run Apache:
node_property$APACHE_2_0 IS NOT NULL
- To define membership as all nodes that run Apache and PHP:
node_property$APACHE IS NOT NULL and node_property$PHP IS NOT NULL
- To define membership as all nodes that run WebSphere
Application Server Community Edition Version 2.0 or later:
node_property$WASCE_2.0* IS NOT NULL
- To define membership as all nodes that run WebSphere
Application Server Community Edition Version 2.0 only:
node_property$WASCE_2.0 IS NOT NULL
- To define membership as all nodes that have a name that is like my_node,
including my_node_1, my_node_2, and so on:
node_name like 'my_node%'
- To define membership as a list of specific host names:
node_hostname in ('node1.mydomain.com','node2.mydomain.com')
You can group subexpressions by using
and,
or, or
not logical
operators and parenthesis. The following example defines node membership as
nodes that are not in the my_node_group node group, and have a name that is
like
my_node, including
my_node_1,
my_node_2, and
so on.
not (node_nodegroup='my_node_group') and node_name like 'my_node%'
- Minimum number of cluster instances
Specifies the minimum number of running instances for the dynamic
cluster. If a minimum value is excessive, performance degradation might occur.
- If you want to stop instances when no activity exists, then click Stop
all instances during periods of inactivity. If you select this option,
then enter the Time to wait before stopping instances value in minutes.
Restriction: If you are routing Session Initiation
Protocol (SIP) traffic to the dynamic cluster, do not use the If other
dynamic clusters need resources, stop all instances of this cluster during
periods of inactivity option. Use one of the options that keep at least
one cluster member active at all times.
- If you want one cluster instance started at all times, then click Keep
one instance started at all times. This option is the default.
- If you want more than one cluster instance started at all times, then
click Keep multiple instances started at all times. If you select this
option, then enter the Number of instances that you want started at
all times.
- Maximum number of cluster instances
Specifies the maximum number of cluster instances that can start.
- If you want to limit the number of cluster instances, click Limit the
number of instances that can start, and enter the maximum Number of
instances.
- If you do not want to limit the number of cluster instances, click Do
not limit the number of instances that can start.
- Vertical stacking of instances on a node
Specifies if more than one instance can start on a single node.
By configuring vertical stacking, the application placement controller can
start more than one instance of the dynamic cluster on the node when a large
workload exists.
Use vertical stacking to improve bottleneck conditions between
applications. Select Allow more than one instance to start on the same
node, and type the Number of instances value. The number of instances
is the number of application servers for a cluster that are needed to use
all the power of a node. Also, the number you choose for vertical stacking
is the number of servers that are automatically created.
If you use target nodes for vertical stacking that are
at an older product version than the deployment manager version, then adding
new members on the same node is disabled. Vertical stacking is available only
on application servers, WebSphere Application Server Community Edition
servers, and PHP servers that have cluster members that are automatically
defined by rules.
- Isolation preference
Specifies if you want the dynamic cluster
to run on the same nodes as other instances of dynamic clusters, or if you
want the dynamic cluster to be the only dynamic cluster that is running on
a node. This option is available if you choose to automatically define your
cluster members with rules.If you manually define your cluster members, you
do not have the option to enable dynamic cluster isolation.
- Select No isolation requirements if cluster instances in this dynamic
cluster can run on the same node as other instances from different dynamic
clusters. This option is the default.
- Select Strict isolation if cluster instances in this dynamic cluster
can run only with other instances of the same dynamic cluster on the same
node.
- Select Associate with an isolation group if the cluster instance
can run with any other instance of a dynamic cluster that is in the same shared
group on the same node. Specify an Isolation group name value. To create
a new isolation group for this dynamic cluster, type a unique name. To select
from a list of the existing isolation groups, click Browse. A topology
of the current isolation groups is displayed. Click an isolation group name
to select the group.
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