open-liberty - extend transaction timeout for specific operation

Question

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.

Answer 1

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>