Premigration considerations

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

• After you install WebSphere Application Server Version 8.5, you might want to build a complete WebSphere Application Server Network Deployment cell configuration and verify that it works correctly before you attempt to migrate an existing cell or node.

  This process ensures that your system has all of the necessary prerequisites and supports the new level of WebSphere Application Server.

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  For more information, see Deprecated, stabilized, superseded, and removed features.

• High-availability manager (HAM) and core-group functionality are included in WebSphere Application Server Version 6.1 and later.

  See Core group migration considerations for core-group configuration and topology considerations that might impact your migration from Version 6.1 or later to Version 8.5.

  Note: In most cases the recommended number of servers in a core group should not exceed 50. You receive a warning message when the migration tools add a server that exceeds the recommended limit.
• 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.

• When migrating a cell with multiple nodes, the applications must remain at the lowest JDK level until all nodes are migrated.
• 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.

• Consider the following information if you are planning to have any mixed-release cells:
  • You can upgrade a portion of the nodes in a cell to WebSphere Application Server Version 8.5 while leaving others at the previous release level. This means that, for a period of time, you might be administering servers that are at the previous release level and servers that are running the newer release in the same cell.

    In this mixed-release environment, some restrictions on what you can do with servers at the previous release level might exist. For details, see Creating application servers.

• 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
• The following restrictions apply to a deployment manager or job manager migration:
  • The Version 8.5 cell and node names must match the cell and node names in the Version 6.1 configuration.

    If you create a profile with a different cell name or a different node name, the migration fails.

• When migrating a federated node, the WebSphere Application Server Version 8.5 cell name and node name must match their respective Version 6.1 or later names.
• 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.
• If you migrate a node to WebSphere Application Server Version 8.5 and then discover that you need to revert to Version 6.1 or later, see Rolling back environments.
• If you have a web services gateway running on a WebSphere Application Server Version 6.1 or later application server that is part of a WebSphere Application Server Network Deployment cell and you want to migrate the cell from a Version 6.1 or later to a Version 8.5 deployment manager, you must first preserve the gateway configuration as described in the coexisting with previous gateway versions article in the Version 6.1 documentation.
• 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.
• You should be aware of the following rules related to migrating security domains:
  • If you migrate a deployment manager that has a security domain with a cell-level scope, the migration tools take the following actions:
    • Migration creates a domain in the new configuration called PassThroughToGlobalSecurity if it does not already exist.
    • Migration adds a cluster mapping to the new configuration for all clusters that existed in the old configuration.
      • Clusters that only existed in the Version 8.5 deployment-manager configuration before migration do not have their mappings to PassThroughToGlobalSecurity changed.
        • If mappings for the Version 8.5 clusters exist before migration, they still exist after migration.
        • If no mappings for the Version 8.5 clusters exist before migration, they still do not exist after migration.
      • If a cluster exists in both the previous configuration and the Version 8.5 configuration before migration, the cluster in the new configuration is added to the PassThroughToGlobalSecurity domain and behaves like the cluster in the previous release.
    • Migration adds a bus mapping for any busses that exist in a migrated Version 6.1.x configuration.

      Bus mappings are updated following the same rules as those for cluster mapping.

    • Administrative servers (deployment manager) are not added to the PassThroughToGlobalSecurity domain.
  • If you migrate a federated node that has a security domain with a cell-level scope, the migration tools take the following actions:
    • Migration creates a domain in the new configuration called PassThroughToGlobalSecurity if it does not already exist.
    • Migration adds a server-level mapping to the PassThroughToGlobalSecurity domain for all non-clustered servers in the old node's configuration.
      • Servers on the node that is being migrated that are part of a cluster do not receive entries in the PassThroughToGlobalSecurity domain because this was addressed through a cluster mapping during deployment-manager migration.

        If you have removed that mapping, migration maintains that behavior.

      • Administrative servers (node agents) are not added to the PassThroughToGlobalSecurity domain.

  For more information, see the Security domains in a mixed-version environment section of Multiple security domains.

• 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.