Premigration considerations

Considerations for AIX®, HP-UX, IBM i, Linux®, Solaris, and Windows operating systems

• Before you perform the migration, evaluate the items deprecated in WebSphere Application Server Version 8.5.

  For more information, see Deprecated, stabilized, superseded, and removed features.

• Before you migrate to Java™ Standard Edition (SE) Development Kit (JDK) 6 from JDK 5 or JDK 1.4 , review your applications for necessary changes based on the Java specification. IBM® WebSphere SDK Java Technology Edition Version 6.0 is installed by default with WebSphere Application Server Version 8.5. Optionally, you can use the Installation Manager to install IBM WebSphere SDK Java Technology Edition Version 7.0.
  Avoid trouble: Do not enable SDK Java Technology Edition Version 7.0 unless all nodes are migrated to Version 8.5 and all nodes are also upgraded to SDK Java Technology Edition Version 7.0. Using SDK Java Technology Edition Version 6.0 and Version 7.0 in the same cell can result in application deployment incompatibilities.

  See Migrating API and specifications for more information.

• The migration articles in this documentation assume that WebSphere Application Server Version 8.5 is being installed in an environment where it must coexist with previous versions of WebSphere Application Server.
  Consider the following items when planning to enable coexistence:

  • Update prerequisites to the levels required by WebSphere Application Server Version 8.5.

    Previous versions of WebSphere Application Server continue to run at the higher prerequisite levels.

  • Review the ports that have been defined to ensure that the WebSphere Application Server Version 8.5 installation does not conflict.

    See Port number settings for default port information.

  See Running multiple application server versions for more information.

• WebSphere Application Server Version 8.5 migration converts HTTP transports to channel-framework web container transport chains.
  For more information on WebSphere Application Server Version 8.5 transport support, see the following information:

  • Configuring transport chains
  • HTTP transport channel settings
  • Transport chains
• If you create a profile that does not meet the migration requirements such as naming requirements, you can remove the previous profile and create a new one rather than uninstalling and reinstalling the WebSphere Application Server Version 8.5 product.
• The migration tools create a migration backup directory containing a backup copy of the configuration from the previous version. The following guidelines might help you to determine the amount of file-system space that this directory might require:
  • If you are migrating from Version 6.1 or later, the space available for this directory must be at least the size of the configuration directory and applications from the previous profile.
• If you use the migration tools to create more than one Version 8.5 target profile on the same host or installation instance and you use the default port settings, there is a chance that the target profiles will share the same ports for some of the new Version 8.5 port definitions. This will cause startup problems if both of the migrated profiles are used.
  If you are migrating two or more profiles that reside on the same host or installation instance, perform the following actions for each additional target profile:

  1. Before using the migration tools, use the Profile Management tool or manageprofiles command to create the target profile and make sure that you select unique ports rather than using the default ports.
  2. When you use the migration tools, select the target profile rather than letting the tools create it.
• The amount of storage that your system requires during migration to Version 8.5 depends on your environment as well as on the migration tool that you are using.
  • WASPreUpgrade storage requirements
    • Location: Backup directory specified as a parameter of the WASPreUpgrade command
    • Amount: For an estimate of your storage requirements when using this command, add the following amounts.
      • Size of the following items for all of the profiles in your previous configuration:
        • profile_root/installableApps directory
        • profile_root/installedApps directory
        • profile_root/config directory
        • profile_root/properties directory
        • Shared libraries referenced in the libraries.xml configuration files
        • Resource adapter archive (RAR) files referenced in the resources.xml configuration files
      • If trace is enabled, which is the default, up to 200 MB (depending on the size and complexity of your configuration)
    For more information about this command, see WASPreUpgrade command.
  • WASPostUpgrade storage requirements
    • For an estimate of your storage requirements when using this command, add the following amounts.
      • Location: New configuration relative to the new profile_root directory
        Size of the following items for the previous profile that you are migrating:

        • profile_root/installableApps directory
        • profile_root/installedApps directory
        • profile_root/config directory
        • profile_root/properties directory
        • Shared libraries referenced in the libraries.xml configuration files
        • RAR files referenced in the resources.xml configuration files
      • Location: Backup directory specified as a parameter of the WASPreUpgrade and WASPostUpgrade commands

        If trace is enabled, which is the default, up to 1 GB (depending on the size and complexity of your configuration)

    For more information about this command, see WASPostUpgrade command.
• If you use isolated data repositories—specifically, nonshared data repositories such as transaction logs for SIB and Apache Derby databases—and you migrate from a previous release, your existing databases and transaction logs are saved when the WASPreUpgrade command is run. Any database changes that you make after you run the WASPreUpgrade command are not reflected in the migrated environment.
  • If you have mission-critical information that is stored in these local data repositories, you should safely shut down all servers that interact with those repositories before attempting migration. Those servers should remain offline until the migration has been successfully completed or rolled back.
  • If you make multiple attempts at migration, either because of unexpected rollback or to apply fixes, rerun the WASPreUpgrade command so that any changes to your isolated data repositories are reflected in the migrated environment.
  After the migration is complete or you have rolled back to the previous version, you can restart the servers that interact with these isolated data repositories.
• Do not migrate a node with active servers if the SIB uses the file-store option for one or all of the messaging engines.
  • The WASPreUpgrade command fails with a file-locked exception when you try to copy the file stores on an active application server.
  • The WASPreUpgrade command copies a locked file, which could compromise data consistency.
  A data store for the messaging engine is an option for a hot migration; but if a file store must be used, the servers should not be running.
• If you try to run the WASPreUpgrade command to migrate from Version 6.1 with the node and application server that own the SIB file store still running, you might get an error similar to the following:

  C:\was80A\bin>WASPreUpgrade c:\bkupWAS6.1.0.17June30B C:\was61B 
  MIGR0385I: Starting to save profile AppSrv01. 
  MIGR0215W: The migration function cannot copy the file and open the destination file 
  c:\bkupWAS6.1.0.17June30B\migrated\C_\FSJune19\Log. 
  MIGR0272E: The migration function cannot complete the command. 

  If you then shut down the application server and node, the WASPreUpgrade command completes.
• Before you migrate an Apache Derby database, ensure that any application servers hosting applications that are using the Apache Derby database are closed. Otherwise, the Apache Derby migration fails.
• If you updated your java.security file in the previous version of WebSphere Application Server, ensure that your updates are located in the migrated java.security file, which is located in V85WAS_HOME/java/jre/lib/security/java.security.
• The process for disabling credential prompting has changed.

  To disable credential prompting in Version 8.5, configure the ipc.client.props to disable credential prompting before migrating from Version 6.1 to Version 8.5.

• During migration, some of your application metadata might be reset to the default and cause the application to function differently from what you expect.

  If you installed an application in your old environment with Use Metadata From Binaries set to true and during that installation or a future update of the application you made a change to the application's metadata (such as JNDI resource references or database entries for example), the change might be lost when you migrate.

  When Use Metadata From Binaries is set to true, the administrative code only updates the metadata in the binary EAR file. This option is not supported in a mixed cell; therefore, it is automatically turned to false as part of migration. When this happens, the expanded metadata in the configuration directories take precedence over the values in the binary EAR file. This causes the values from the original EAR file installation to take precedence over any updates that you might have made.

  Perform one of the following actions to resolve this issue:

  • Before migrating, update your applications in the old environment and set Use Metadata From Binaries to false. Ensure that the applications are functioning correctly with this new setting, and then run the migration.
  • After migrating, update your applications and correct the metadata as required to allow the applications to function appropriately.
• After you use the migration tools to migrate to WebSphere Application Server Version 8.5, you might need to perform some actions that are not done automatically by the migration tools.
  • Examine any Lightweight Third-Party Authentication (LTPA) security settings that you might have used in WebSphere Application Server Version 6.1 or later, and verify that Version 8.5 security is set appropriately.

    See Lightweight Third Party Authentication for more information.

  • Check the WASPostUpgrade.log file in the logs directory for details about any JavaServer Pages (JSP) objects that the migration tools did not migrate.

    If Version 8.5 does not support a level for which JSP objects are configured, the migration tools recognize the objects in the output and log them.

  • Review your Java Virtual Machine (JVM) settings to verify that you are using a heap size of at least 50 for improved startup performance.

    See Java virtual machine settings for more information.

    If you have used a smaller heap size before, you can use the default heap size of 50.

  • Verify the results of the automatic Apache Derby database migration, and manually migrate any Apache Derby databases that are not automatically migrated by the tools.

    See Migrating Apache Derby databases for more information.

  • WebSphere Application Server Version 8.5 does not include the WebSphere Connect JDBC driver for SQL Server. The WebSphereConnectJDBCDriverConversion tool is provided to convert data sources from the WebSphere Connect JDBC driver to the DataDirect Connect JDBC driver or the Microsoft SQL Server JDBC driver.

    See Migrating from the WebSphere Connect JDBC driver for more information.