[CAMEL-16091] Using netty-http with enricher causes buffer leak

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.7.1
• Fix Version/s: 3.7.2, 3.8.0
• Component/s: came-core, camel-netty-http
• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Michał Ostrowski
• Created: 27/Jan/21 11:53
• Updated: 30/Jan/21 15:12
• Resolved: 30/Jan/21 15:12

Description

NettyHttpProducer depends on onCompletion synchronization do release allocated buffer. However content enricher could create exchanges without UnitOfWork. Here is example unit test to reproduce issue:

EnricherIssueTest.java

public class EnricherIssueTest extends CamelTestSupport {

    @Test
    public void leakTest() {
        ResourceLeakDetector.setLevel(Level.PARANOID);
        for (int i = 0; i < 10; ++i) {
            template.requestBody("direct:outer", "input", String.class);
        }
    }

    @Override
    protected RoutesBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {

            @Override
            public void configure() throws Exception {
                ResourceLeakDetector.setLevel(Level.PARANOID);

                final int port = AvailablePortFinder.getNextAvailable();

                from("netty-http:http://localhost:" + port + "/test")
                    .transform().simple("${body}");

                from("direct:outer")
                    .enrich("netty-http:http://localhost:"+ port + "/test?disconnect=true",
                        AggregationStrategies.string(), false, false);
            }
        };
    }
}

Setting shareUnitOfWork=true on enrich() causes snippet to behave correctly.
I'm not sure where is the bug. Does Enricher is allowed to create exchanges without UOW? Maybe org.apache.camel.component.netty.http.NettyHttpProducer should create UOW if none is available? Or maybe my usage is wrong?