Apache camel Connection pool timeout with restlet even after configuring component options

Question

I have a camel Java DSL route which invokes a restlet endpoint. And the route works without any issues when I hit the same manually. But, when I try to pump a larger number of requests through code I'm getting "Timeout waiting for connection from pool"

And the following is stackt-race of the same:

2016-01-29 14:09:38.650  WARN 20256 --- [pool-3-thread-2] org.restlet                              : An error occurred during the communication with the remote HTTP server.org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool
at org.apache.http.impl.conn.tsccm.ConnPoolByRoute.getEntryBlocking(ConnPoolByRoute.java:412)
at org.apache.http.impl.conn.tsccm.ConnPoolByRoute$1.getPoolEntry(ConnPoolByRoute.java:298)
at org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager$1.getConnection(ThreadSafeClientConnManager.java:238)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:423)
at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:863)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57)
at org.restlet.ext.httpclient.internal.HttpMethodCall.sendRequest(HttpMethodCall.java:339)
at org.restlet.engine.adapter.ClientAdapter.commit(ClientAdapter.java:105)
at org.restlet.engine.adapter.HttpClientHelper.handle(HttpClientHelper.java:119)
at org.restlet.Client.handle(Client.java:153)
at org.restlet.Restlet.handle(Restlet.java:275)
at org.apache.camel.component.restlet.RestletProducer.process(RestletProducer.java:79)
at org.apache.camel.component.restlet.RestletProducer.process(RestletProducer.java:98)
at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:141)
at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:460)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.processor.Pipeline.process(Pipeline.java:121)
at org.apache.camel.processor.Pipeline.process(Pipeline.java:83)
at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:460)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.processor.MulticastProcessor.doProcessSequential(MulticastProcessor.java:668)
at org.apache.camel.processor.MulticastProcessor.doProcessSequential(MulticastProcessor.java:596)
at org.apache.camel.processor.MulticastProcessor.process(MulticastProcessor.java:237)
at org.apache.camel.processor.Splitter.process(Splitter.java:104)
at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:460)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.processor.Pipeline.process(Pipeline.java:121)
at org.apache.camel.processor.Pipeline.process(Pipeline.java:83)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.component.direct.DirectProducer.process(DirectProducer.java:62)
at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:141)
at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:460)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:109)
at org.apache.camel.processor.MulticastProcessor.doProcessParallel(MulticastProcessor.java:814)
at org.apache.camel.processor.MulticastProcessor.access$200(MulticastProcessor.java:84)
at org.apache.camel.processor.MulticastProcessor$1.call(MulticastProcessor.java:314)
at org.apache.camel.processor.MulticastProcessor$1.call(MulticastProcessor.java:299)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

And as per the doc I did configure the restlet component with the following code but I'm still seeing the same issue:

    @Bean
public RestletComponent restlet()
{
    RestletComponent restlet = new RestletComponent();
    restlet.setMaxThreads(100);
    restlet.setThreadMaxIdleTimeMs(10000);
    restlet.setMaxQueued(20);
    return restlet;
}

Note: The route did accepted 10 requests at a time then I started getting errors. And from configuration I could see the maxThreads by default is 10. Which means the that I did through Bean is not picking up properly.

Answer 1

Actually in my code I have defined restlet bean after route configure i.e as below

public class RoutesBuilder extends FatJarRouter {

....

@Override
    public void configure() throws JAXBException {
    ......
}

@Bean(name={"restlet"})
    public RestletComponent restlet()
    {
        .......
    }
}

And now I have changed the order of defining the code as i.e first I have defined restlet and the route configure as below. With that in place I saw the restlet configuration is been picked up and I no more see the connection pool issue.

public class RoutesBuilder extends FatJarRouter {

....

@Bean(name={"restlet"})
    public RestletComponent restlet()
    {
        .......
    }

@Override
    public void configure() throws JAXBException {
    ......
}


}

Answer 2

Check these things:

1. Make sure you have enabled <context:annotation-config/> in the Spring App Context XML file.
2. Use <context:component-scan base-package="<your package>" /> in the Spring XML.
3. Make sure you have annotated the containing that @Bean with @Configuration.
4. Add the name attribute to the @Bean: @Bean(name={"restlet"}).

Hope that helps.