Cluster member settings

Use this page to manage the members of a cluster. A cluster of application servers are managed together and participate in workload management.

A copy of the first cluster member that you create is stored as part of the cluster data and becomes the template for all additional cluster members that you create.

Any individual configuration change that you make to a cluster member does not affect the configuration settings of the cluster member template. You must use wsadmin commands to modify the cluster member template.

To view this administrative console page, click Servers > Clusters > cluster_name > Cluster members > cluster_member_name.

Configuration tab

Member name

Specifies the name of the server in the cluster. On most platforms, the name of the server is the process name. The name must match the (object) name of the application server.

Data type String

Weight

Controls the number of requests that are directed to the application server. Even though you specify a value of 0 to 20 as the weight of a server, the weight that is given to the server as a member of a cluster is a proportion that is based on the weight assigned to the server (the numerator) and the sum of the weights of all members of the cluster (the denominator).

When you add a new member to a cluster, the number of requests that are sent to each server in the cluster decreases, assuming the number of requests coming into the cluster stays the same. Similarly when you remove a new member from a cluster, the number of requests that are sent to each server in the cluster increases, assuming the number of requests coming into the cluster stays the same.

For example, if you have a cluster that consists of members A, B, and C with weights 2, 3, and 4, respectively, 2/9 of the requests are assigned to member A, 3/9 are assigned to member B, and 4/9 are assigned to member C. If a new member, member D, is added to the cluster and member D has a weight of 5, member A now gets 2/14 of the requests, member B gets 3/14 of the requests, member C gets 4/14 of the requests, and member D gets 5/14 of the requests.

[z/OS] On the z/OS platform, weight is used to balance some of the workload types, but others are balanced by the z/OS system.
  • For HTTP requests, weights are used to distribute HTTP traffic between the Web server plug-in and the controller handling the clustered application server. Assign a higher weight value to the application server that should receive the HTTP traffic.
  • For Web services calls, information is transferred from a servant in one application server to a controller in another application server. The application server that receives the call has the highest weight value.
  • Weight has no affect on Internet Inter-ORB Protocol (IIOP) requests. IIOP requests are distributed to the correct application server using the sysplex distributor.
Data type Integer
Range 0 to 20

Unique ID

Specifies a numerical identifier for the application server that is unique within the cluster. The ID is used for affinity.

Data type Integer
Data type Hexadecimal

Short name

[z/OS]

Specifies the short name for this cluster member. This field only applies to the z/OS platform.

The short name is the default z/OS job name and identifies the cluster member to the native facilities of the operating system, such as Workload Manager (WLM), Automatic Restart Manager, SAF (for example, RACF), started task control, and others.

If you specify a short name for a cluster member, the name:
  • Must be one to eight characters in length. By default, WebSphere Application Server for z/OS assumes you are using a 7-character server short name (JOBNAME). If your naming standards require 8 characters, you can lengthen the 7-character server short name to 8 characters.
  • Must contain only uppercase alphanumeric characters
  • Cannot start with a number.
  • Must be unique in the cell
  • Cannot be the same as the value specified on the ClusterTransitionName custom property of any non-clustered server. Do not specify a cluster transition name for a server that is part of a cluster.

If you do not specify a short name, the system assigns a default short name that is automatically unique within the cell. You can change the generated short name to conform with your naming conventions.

Data type String

Run in development mode

Enabling this option may reduce the startup time of an application server. This may include JVM settings such as disabling bytecode verification and reducing JIT compilation costs. Do not enable this setting on production servers.

[iSeries] This option is not supported in an i5/OS environment.

Specifies that you want to use the JVM settings -Xverify and -Xquickstart on startup. After selecting this option, save the configuration and restart the server to activate development mode.

The default setting for this option is false, which indicates that the server will not be started in development mode. Setting this option to true specifies that the server will be started in development mode (with settings that will speed server startup time).

Data type Boolean
Default false

Parallel start

Specifies whether to start the server on multiple threads. Starting the server on multiple threads might shorten the startup time.

Specifies that you want the server components, services, and applications to start in parallel rather than sequentially.

The default setting for this option is true, which indicates that the server be started using multiple threads. Setting this option to false specifies that the server will not be started in using multiple threads (which may lengthen startup time).

The order in which applications start depends on the weight you assign to each application. The application with the lowest starting weight starts first. Applications with the same starting weight start in parallel. You use the Starting weight field on the Applications > Enterprise Applications > application_name page of the administrative console to set the starting weight for an application.

Data type Boolean
Default true

Access to internal server classes

Specifies whether the applications can access many of the server implementation classes.

If you select Allow, applications can access many of the server implementation classes. If you select Restrict, applications can not access many of the server implementation classes. The applications get a ClassNotFoundException if they attempt to access those classes.

Applications typically use the supported APIs and do not need to access system internals.

The default value for this property is Allow.

Class loader policy

Specifies whether there is a single class loader to load all applications or a different class loader for each application.

Runtime tab

Member name

Specifies the name of the server in the cluster. On most platforms, the name of the server is the process name. The name must match the (object) name of the application server.

Data type String

Weight

Controls the number of requests that are directed to the application server. Even though you specify a value of 0 to 20 as the weight of a server, the weight that is given to the server as a member of a cluster is a proportion that is based on the weight assigned to the server (the numerator) and the sum of the weights of all members of the cluster (the denominator).

When you add a new member to a cluster, the number of requests that are sent to each server in the cluster decreases, assuming the number of requests coming into the cluster stays the same. Similarly when you remove a new member from a cluster, the number of requests that are sent to each server in the cluster increases, assuming the number of requests coming into the cluster stays the same.

For example, if you have a cluster that consists of members A, B, and C with weights 2, 3, and 4, respectively, 2/9 of the requests are assigned to member A, 3/9 are assigned to member B, and 4/9 are assigned to member C. If a new member, member D, is added to the cluster and member D has a weight of 5, member A now gets 2/14 of the requests, member B gets 3/14 of the requests, member C gets 4/14 of the requests, and member D gets 5/14 of the requests.

[z/OS] On the z/OS platform, weight is used to balance some of the workload types, but others are balanced by the z/OS system.
  • For HTTP requests, weights are used to distribute HTTP traffic between the Web server plug-in and the controller handling the clustered application server. Assign a higher weight value to the application server that should receive the HTTP traffic.
  • For Web services calls, information is transferred from a servant in one application server to a controller in another application server. The application server that receives the call has the highest weight value.
  • Weight has no affect on Internet Inter-ORB Protocol (IIOP) requests. IIOP requests are distributed to the correct application server using the sysplex distributor.
Data type Integer
Range 0 to 20

Process Id

Specifies the native operating system process ID for this server.

The process ID property is read only. The system automatically generates the value.

Cell name

Specifies the name of the cell in which this server is running.

The Cell name property is read only.

Node name

Specifies the name of the node in which this server is running.

The Node name property is read only.

State

Specifies the run-time execution state for this server.

The State property is read only.




Related concepts
Clusters and workload management
Related tasks
Adding members to a cluster
Configuring application startup
Modifying cluster member templates using scripting
Related reference
Cluster member collection
Reference topic    

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Last updated: Feb 19, 2011 5:25:36 AM CST
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