Why is the option available to Start an Application Server from the administrative console in a multi-node domain when the node is not started
 Technote (FAQ)
 
Problem
Should the Start option be grayed out if the node is not started?
 
Solution
The following scenario explains why the Start option is not grayed out.

Scenario
A company has multiple geographically separated locations with a WebSphere Administrator at each location. They have three Node environments in a single domain. The nodes are Node A, Node B and Node C. Node A and Node C are running, but Node B is not. You start the administrative console on Node A and see topologies for all three nodes.

Question 1
If Node B is not running for whatever reason, why is there an option under the right-click on an Application Server on Node B? It can't start the needed JVM™ so we know it will fail and issue a lot of errors.

Explanation
This is working as WebSphere Application Server 4.0 was designed. In WebSphere Application Server 4.0, the Start and Stop options are never greyed on the application and module level, because each application can include many EJB™ or Web modules under different Application Servers or nodes if in a cluster environment.

For example, we cannot gray the Start or Stop option for an application if it contains two EJB modules assigned to different Application Servers during the .ear installation. When one module is started (running) and another module is stopped, the stopped module can never start if we gray the Start option. Also, we cannot gray the Stop option when the module is in Running state.

It is very expensive and might affect performance to gray the Start or Stop button on application or module level, because we must check the modules status, and we also must check the associated Application Servers, Server Groups or Nodes status. In many
cases, it is difficult to decide what should be the final or corresponding status of the application when some modules are in a Running state and others are in a Stopped state.
Question 2
How can WebSphere Administrators effectively administer their portion of the domain without interfering with each other?

Explanation
We suggest that there be one administrator administering a domain at a given time. To avoid the confusion and error situation, you can always check status by right-clicking an application or individual module, then selecting Show Status prior to any attempts to Start or Stop an application. Show Status clearly displays the module-server relationship (which module is under which server) and the current status of the module. If an application includes modules and all are assigned to the same application server, you can start the application when the status on the modules shows Stopped. You can stop the application when the status shows Running (server is started).

When you stop one node in a multi-node environment, the Show Status for the module displays Lost Contact, which means that the module under the node that is no longer active or the administrative console is losing the connection to the administrative server. This error is expected because the node is not active to start the application.

 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Administrative Console (all non-scripting)
Operating system(s): Windows
Software version: 4.0.7
Software edition:
Reference #: 1063291
IBM Group: Software Group
Modified date: Mar 27, 2006