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Laura Cowen edited this page Oct 1, 2025 · 131 revisions

This wiki provides a collection of links to information about how to migrate a WebSphere Application Server application to run on Liberty.

The wiki is managed and curated by Laura Cowen, Technical Content Strategist and Developer Advocate at IBM. Contributions and feedback are welcome from WebSphere users and subject matter experts.

For more info about the wiki aims and how to contribute, see the README.

To search for information, use your browser's search in page feature (CTRL+F).

If there is something missing from the wiki, or you have information that would answer a question on the wiki, please raise an issue.

Liberty overview

  • WebSphere Liberty built on Open Liberty (WL docs)
  • Economics of Liberty (issue)
  • Intro to Liberty from a tWAS perspective (issue)
  • Overview of various target platforms for apps and when to choose them (eg MoRE (Liberty with tWAS operations), EASeJ (Liberty on SaaS), Liberty on VM, Liberty in containers, etc) (issue)
  • Liberty downloads and licensing options and guidance (issue)

Why Liberty

Liberty architecture overview

Liberty operations overview

  • Liberty "demystified" (internal)
    • Write up and publish.
    • Create videos? (either clip from Alasdair's or create new)

Deployment options:

Liberty application support overview

Overview of differences between Liberty and WebSphere

(LC: Ultimately, I think this would be more useful to be framed in terms of goals, as "I do it this way on WebSphere; how should I do it on Liberty?", rather than highlighting the differences.)

Architectural differences overview

Operational differences overview

  • Overview of operational differences between WebSphere and Liberty (issue) Cover the following topics at a high level:
    • Administrative interfaces (admin console, wsadmin scripting)
    • VM vs container deployment
    • Scaling
    • Failover
    • Centralized management
    • etc? (see for list of topics Liberty "demystified" (internal))

(Provide links out to detailed instructions in later sections.)

Application framework differences overview

  • Overview of application framework differences (issue) Cover the following topics at a high level:
    • Java SE versions
    • Java EE / Jakarta EE versions
    • Remote transaction propagation between remote EJBs
    • ? Other things likely to be flagged by binary scanner?

(Provide links out to detailed instructions in later sections.)

Getting to know Liberty

While tWAS applications are largely compatible with running on Liberty, Liberty is not identical to tWAS. Before you start to migrate a tWAS application to run on Liberty, it is worth becoming familiar with writing and running apps on Liberty. WebSphere Liberty is built on Open Liberty; apart from a small number of additional capabilities in WebSphere Liberty, the WebSphere Liberty and Open Liberty runtimes are the same.

See Other resources for more help.

Planning a migration

How to migrate operations to Liberty

Topic Resources available (description, link, and type) Sources of info to create missing resources
Operations: Moving from Admin Console to Liberty admin center, EAseJ, MoRE, etc. (issue) Alasdair's "demystified" presentation (internal; issue); Liberty Admin Center; WebSphere admin console; wsadmin scripting;
Operations: How to secure the server configuration on Liberty Security Configuration Hardening docs
Operations: How to do centralised management in Liberty Alasdair's "demystified" presentation (internal)
Operations: How to load-balance across Liberty servers Alasdair's "demystified" presentation (internal)
Operations: How to manage plugin config of dynamic routing in Liberty Alasdair's "demystified" presentation (internal)
Operations: Licences and entitlement to run Liberty Alasdair's "demystified" presentation (internal)
Operations: Messaging engine compatibility between tWAS and Liberty
Operations: How to script deployments on Liberty Alasdair's "demystified" presentation (internal)
Operations: How to do HTTP session persistence on Liberty Alasdair's "demystified" presentation (internal)
Operations: How to tune Liberty performance Threadpool tuning Liberty; Performance tuning Liberty; Faster responses with HTTP response compression on Liberty; Pre-populating database connections for better response times in the cloud; Common performance tuning; Some known migration issues mostly around performance(mostly tWAS to tWAS but some Java and Linux related points that would apply to going to Liberty on a newer Java);
Operations: Liberty on z/OS Consider enabling SMF 120 records: HTTP requests may be monitored with SMF 120 subtype 11 records. These records are enabled by adding the zosRequestLogging-1.0 feature to the server configuration and enabling SMF to capture those records. Java batch jobs may be monitored with SMF 120 subtype 12 records. These records are enabled by adding the batchSMFLogging-1.0 feature to the server configuration and enabling SMF to capture those records. Consider WLM classification: zosWlm-1.0
Enable hardware cryptography Java 8, Java 11, Java 17, or Java 21
Operations: How to run older programming models on Liberty (issue)
Operations: How to do high availability (HA) on Liberty Alasdair's "demystified" presentation (internal)
Operations: How to move to Liberty without going to the cloud (issue)
Operations: Can I use Liberty in exactly the same way as tWAS? (issue)
Technical Alasdair's "demystified" presentation (internal) (covers deploying on VMs, centralised mgment, admin console, scripting, IBM HTTP Server config, HA support, performance, licences, TA/AMA, cost)
Technical: Scaling, administration, clusters Alasdair's "demystified" presentation (internal) for overview
How to optimize routing setup for HTTP routing (eg F5, NGINX, Apache mod_rewrite)? (issue)
How to design continuous integration builds with Liberty's Maven plugin? (issue)
Issues to look out for, differences between WebSphere and Liberty and how to handle them (create post from Monica and Barbara's presentation, issue)
Managing Deployment Scripts without WAS ND Alasdair's "demystified" presentation (internal)
Issues to look out for, differences between WebSphere and Liberty and how to handle them - Deploying Liberty on VM’s (Collectives or HTTP Proxy) Kevin's lab (internal)
Issues to look out for, differences between WebSphere and Liberty and how to handle them - How to configure Hardware Security Module (HSM) on z/OS on IBM Java on Liberty (issue)
Hands-on demos/labs Tech Zone demos, VMs, presentations; Liberty to VMs; Liberty to OCP (internal, issue)
How to migrate clusters, in particular session management and failover logic? (issue)
How to update deployment pipelines for Liberty? (issue)

How to migrate applications to run on Liberty

Tips: sequence and “how” for known cases What to do when, suggested sequence of steps

  • Migrate and then update Java version
  • Issues to look out for, differences between WebSphere and Liberty and how to handle them
  • Transaction management
  • Managing Deployment Scripts without WAS ND
  • Deploying Liberty on VM’s (Collectives or HTTP Proxy)
  • Remote transaction propagation between Remote EJB’s not supported
Topic Resources available (description, link, and type)
Issues to look out for, differences between WebSphere and Liberty and how to handle them - Transaction management [add resources here]
Transaction Propagation between Remote EJB’s not supported Transaction propagation on Liberty
How to migrate SOAP endpoints using JAX-RPC? Automating JAX-RPC source code migration
How to migrate authentication using DatabaseServerLoginModule? (issue)
How to validate migrated Filenet connections? (issue)
How to migrate WebSphere SIBus JMS messaging? (issue)
How to migrate hardcoded InitialContext or java:global lookups? See InitialContext and java:global lookups (issue)
How to migrate legacy Spring and Hibernate frameworks that don't support Java 17? Are there common pitfalls? (issue)
What are the differences in WAR structure and classloader locations between tWAS and Liberty? (issue)
Does it matter if some apps use javax and others use jakarta? Is it necessary to migrate fully to Jakarta 10? (issue)
How to validate integrations after migration? (issue)
How to manage third-party dependencies (JARs) in Liberty? (issue)
How to transition existing dashboards and alerts from WebSphere and other inputs to Liberty's JSON logging, MicroProfile Metrics, and OpenTelemetry? (issue)
How to migrate certificates from WebSphere to Liberty's TLS setups for keyStore and SSL? (issue)
How to transition WARs/EARs to Liberty? (issue)
How to configure AD, LDAP, SPNEGO, SAML, OIDC on Liberty? (issue)
Any compatibility issues to watch for moving from Java 8 (Oracle or IBM) to Java 17 (OpenJDK distributions)? (issue)
How to automate JAX-RPC source code migration 20250109 CAB session - Automating JAX-RPC source code migration (video)
How to run Spring Boot apps on Liberty How to Containerize Your Spring Boot Application for Rapid Startup (DZone.com); Running a Spring Boot 3.x application WAR file on Liberty; all Spring Boot blog posts on openliberty.io; missing: "a complete demo/guide that connects our three flagship enterprise products (WebSphere, DB2, MQ) with a spring boot application using Liberty InstantOn to scale to zero on OpenShift and then also show how Semeru cloud compiler can be enabled with Liberty operators to reduce rampup time even more efficiently."; Spring Boot performance (internal; issue)

Client case studies

(these should be organised/presented according to what they demo and/or by industry, etc so they're easily retrieved)

Training

Other resources

Topic Resources available (description, link, and type)
OSS libraries [add resources here]
Documentation Liberty docs (apply to Open Liberty and WebSphere Liberty; WebSphere Liberty docs (for features only available in WebSphere Liberty)
What's new in Liberty? Open Liberty release blog posts; Quarterly webinars; Open Liberty LinkedIn page
Online forums WebSphere & Liberty TechXchange community; WebSphere & Liberty Customer Advisory Board (CAB) TechXchange community
Videos Laura's backups of ExpertTV etc (internal); Grace's video audit (internal) Videos cover topics listed on this whole page but all videos probably need updating.

Suggested article/video ideas

  • I can do x on tWAS, how do I do x on Liberty?
  • Liberty operations for a tWAS operator
  • Code changes probably not needed...but if they are...

Source formats

Each link is labelled to indicate its format:

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