Best practices for upgrading clients

Consider the following best practices when planning your client upgrade.

Determine whether to upgrade clients or DB2® servers first

In general, upgrade clients after you upgrade your DB2 servers is the traditional approach. Supported pre-DB2 Version 10.5 clients can connect to DB2 Version 10.5 servers. However, the functionality introduced in releases after the pre-DB2 Version 10.5 client release is not available. If you plan to use this functionality in your applications, upgrade your clients to DB2 Version 10.5 or install new DB2 Version 10.5 client copies.

You can upgrade your clients before you upgrade your DB2 servers. However, you must ensure that your applications are able to manage any incompatibilities between releases. Review the following topics to determine if any incompatibilities apply to your application, and take necessary actions to manage these incompatibilities:

• Upgrade essentials for database applications for changes to DB2 APIs, DB2 commands, and SQL statements
• DB2 server behavior changes for changes on default values for existing registry variables, database and database manager configuration parameters
• Deprecated or discontinued functionality that affects DB2 server upgrades for discontinued functionality not supported by DB2 Version 10.5 clients
• Changed functionality in DB2 Version 10.5 for additional changes between releases

Upgrade your clients in a test environment

Upgrading clients in a test environment allows you to determine if the upgrade can be successful and to address any problems that might occurred during the upgrade process. You can also test your database applications and determine if you must upgrade them to run successfully in DB2 Version 10.5.

If you are upgrading your clients first, upgrading clients in a test environment allows you to determine and manage any incompatibilities between releases to successfully run your applications on pre-DB2 Version 10.5 servers using DB2 Version 10.5 clients

Install a new client copy instead of upgrading existing client

If you have software that requires a pre-DB2 Version 10.5 client, install the DB2 Version 10.5 client as a new copy and keep your existing client copy to satisfy the software requirement. Then create a DB2 Version 10.5 client instance and keep your existing client instance with its configuration. You can select the option to create a new client instance during the installation, or you can manually create the client instance after installation.

Perform pre-upgrade and post-upgrade tasks

Perform the pre-upgrade and post-upgrade tasks for clients to ensure a successful upgrade.