open-liberty - extend transaction timeout for specific operation

i have a container managed transaction in a REST call with default liberty timeout of 120sec.

I want for a specific operation withtout spawning a new transaction to extend it to 5 minutes. how can i do this?

I know I can change timeout in server.xml, but this would change timeout for all operations.

Liberty UOWManager SPI

You could use the Liberty UOWManager SPI, but you'd have to "clean up" after setting a custom timeout if you want later methods to revert back to the default timeout once this thread goes back to the Liberty thread pool and gets reused.

Transactional CDI Bean

@Dependent
public class MyTransactional {

    @Transactional
    public String myMethod() { ... }

JAX-RS resource class

import static com.ibm.websphere.uow.UOWSynchronizationRegistry.UOW_TYPE_GLOBAL_TRANSACTION;
import com.ibm.wsspi.uow.UOWManager;

   
 ...

    @Resource
    private UOWManager uowm;

    @Inject MyTransactional transactionalBean // annotated with @Transactional

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    @Path("m1")
    public Response m1() throws Exception {
        String r = null;
        int CUSTOM_TIMEOUT_SECONDS = 300; 
        try {     
            uowm.setUOWTimeout(UOW_TYPE_GLOBAL_TRANSACTION, CUSTOM_TIMEOUT_SECONDS);    
            r = transactionalBean.myMethod();        
        } finally {
            // cleanup thread (so it reverts to default timeout after going back in the thread pool)
            uowm.setUOWTimeout(UOW_TYPE_GLOBAL_TRANSACTION, 0);     
        }
        return Response.ok(r).build();
    }

pom.xml

You can add this dependency to your Maven build with an entry like (the version might seem kind of random; it's tied to the Liberty fix pack version but this type of SPI won't likely change too frequently across versions).

        <dependency>
            <groupId>com.ibm.websphere.appserver.api</groupId>
            <artifactId>com.ibm.websphere.appserver.api.transaction</artifactId>
            <version>1.1.82</version>
        </dependency>