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6.5.3: Operational dependencies and best practices

6.5.3: Operational dependencies and best practices

Some configurations require you to start your servers in a certain order or the start will fail. This article documents best practices and "gotchas," as they are discovered through use of the product in realistic environments.

See also the IBM Redbooks about this product edition and version.

Configurations involving EJB modules and Web modules in separate servers

If WebSphere Application Server is configured such that you have separate servers dedicated to running your EJB modules and Web modules, you will have trouble if you start the servers in the wrong sequence. The following scenario illustrates the problem and one solution.

Configuration:

  • Application (Deployed_WLMApp.ear) with both EJB modules and Web modules
  • Two application servers:
    • WLMServletServer (for the Web modules)
    • WLMEJBServer (for the EJB modules)

Error situation:

  1. Create WLMEJBServer.
  2. Create WLMServletServer.
  3. Install application:
    • Select that EJB beans run on WLMEJBServer.
    • Select that Web module runs on WLMServletServer.
  4. Start WLMServletServer:
    • Web module loads and HTTP transport on port 9080
  5. Start WLMEJBServer.
  6. Obtain ERROR because the port 9080 is already in use.

The WLMEJBServer cannot be started, even though no Web modules are installed to it to require the use of port 9080.

Solution:
If the WLMEJBServer had been started first, everything would have been fine, because the WLMEJBServer would have loaded without locking port 9080. The port would have been available when the WLMServletServer started.

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