Before upgrading Java – Checklist

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Required actions

Before upgrading to version 26.2 (and Java 21), we recommend the following steps:

Determine the Java runtime

  • Choose OpenJDK 21 as the target version unless a blocking dependency prevents it.

  • Verify that all critical third-party components (e.g., database drivers) support the newer Java version.

  • Where possible, install the JDK by extracting it into a dedicated directory rather than using the OS installer or package manager. This decouples the JVM from automatic OS updates and allows a fast rollback to the previous Java version. Details: Upgrading from Java 11 to Java 21.

Review databases and JDBC drivers

  • Compile a list of all databases and JDBC drivers in use, including reporting/BI and cloud connectors.

  • For each relevant driver, verify compatibility with both the database version and the target Java version using the respective vendor documentation.

  • Schedule any required driver updates accordingly.

Informix as a hub database is not supported

  • As of version 26.2 (and patches 26.1.5 and 25.1.11 onwards), all Informix JDBC JARs have been removed from IS/lib.

    IMPORTANT Running Informix as the hub database is no longer possible. If you continue to use Informix in other roles, you must provide the driver yourself and place it under IS/extlib.

    • Test connectivity with the target Java version in a test environment.

Validate custom JDOM usage

  • Identify all custom scripts or Java code that use JDOM APIs.

  • Migrate them to JDOM2 as needed.

  • Run regression tests for all affected integrations.

Assess TLS impact

  • Identify systems (databases, services) that still rely on TLS 1.0 or deprecated cipher suites.

  • Update those systems, or – if strictly necessary – plan secured exceptions.

Test in a staging environment

  • Run a full upgrade (platform + Java + drivers) on a test system.

  • Test the most critical end-to-end scenarios:

    • Database access (all database types in use)

    • Reporting and BI integrations

    • SAP connectivity (SAP JCo 3.1.13, if applicable)

    • Other JDBC-based integrations

  • Verify automation rules and smart values: Java 21 updates the Unicode specification. Check that date formats, number formats (decimal separator, thousands separator), and string-based comparisons in your automation rules, dynamic field values, and calculated fields still behave correctly.