disable akka.jvm-exit-on-fatal-error for actorsystem in java

问题

I am using akka actor system for multi threading. It is working fine in normal use-cases. However, Akka is closing JVM on fatal error. Please let me know how I can configure Akka to disable "akka.jvm-exit-on-fatal-error" in java. Below is code.

public class QueueListener implements MessageListener {


    private String _queueName=null; 
    public static boolean isActorinit=false;
    public static ActorSystem system=null;
     private ActorRef myActor;

    public QueueListener(String actorId, String qName){
        this._queueName = qName;
         if(!isActorinit){
                system=ActorSystem.create(actorId);

                isActorinit=true;
            }

          myActor=system.actorOf( Props.create(MessageExecutor.class, qName),qName+"id");
    }


    /* 
     * (non-Javadoc)
     * @see javax.jms.MessageListener#onMessage(javax.jms.Message)
     */
    @Override
    public void onMessage(Message msg) {

        executeRequest(msg);
    }




    /** This method will process the message fetch by the listener.
     *   
     * @param msg - javax.jms.Messages parameter get queue message
     */
    private void executeRequest(Message msg){

        String requestData=null;
        try {

            if(msg instanceof TextMessage){
                TextMessage textMessage= (TextMessage) msg;
                requestData = textMessage.getText().toString();
            }else if(msg instanceof ObjectMessage){
                ObjectMessage objMsg = (ObjectMessage) msg; 
                requestData = objMsg.getObject().toString();
            }
            myActor.tell(requestData, ActorRef.noSender());

        } catch (JMSException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

    }

}

回答1:

Create an application.conf file in your project (sr/main/resources for example) and add the following content:

akka {
  jvm-exit-on-fatal-error = false
}

No need to create new config file if you already have one of course, in that case it is just adding the new entry:

jvm-exit-on-fatal-error = false

Be careful. Letting the JVM run after fatal errors like OutOfMemory is normally not a good idea and leads to serious problems.

回答2:

See here for the configuration details - you can provide a separate config file, but for the small number of changes I was making to the akka config (and also given that I was already using several Spring config files) I found it easier to construct and load the configuration programmatically. Your config would look something like:

import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;

StringBuilder configBuilder = new StringBuilder();
configBuilder.append("{\"akka\" : { \"jvm-exit-on-fatal-error\" : \"off\"}}");
Config mergedConfig = ConfigFactory.load(ConfigFactory.parseString(configBuilder.toString()).withFallback(ConfigFactory.load()));
system = ActorSystem.create(actorId, mergedConfig);

This is loading the default Config, overriding its jvm-exit-on-fatal-error entry, and using this new Config as the config for the ActorSystem. I haven't tested this particular config, so there is a 50% chance that you'll get some sort of JSON parsing error when you try to use it; for comparison, the actual config I use which DOES parse correctly (but which doesn't override jvm-exit-on-fatal-error) is

private ActorSystem createActorSystem(int batchManagerCount) {
    int maxActorCount = batchManagerCount * 5 + 1;

    StringBuilder configBuilder = new StringBuilder();
    configBuilder.append("{\"akka\" : { \"actor\" : { \"default-dispatcher\" : {");
    configBuilder.append("\"type\" : \"Dispatcher\",");
    configBuilder.append("\"executor\" : \"default-executor\",");
    configBuilder.append("\"throughput\" : \"1\",");
    configBuilder.append("\"default-executor\" : { \"fallback\" : \"thread-pool-executor\" },");

    StringBuilder executorConfigBuilder = new StringBuilder();

    executorConfigBuilder.append("\"thread-pool-executor\" : {");
    executorConfigBuilder.append("\"keep-alive-time\" : \"60s\",");
    executorConfigBuilder.append(String.format("\"core-pool-size-min\" : \"%d\",", maxActorCount));
    executorConfigBuilder.append(String.format("\"core-pool-size-max\" : \"%d\",", maxActorCount));
    executorConfigBuilder.append(String.format("\"max-pool-size-min\" : \"%d\",", maxActorCount));
    executorConfigBuilder.append(String.format("\"max-pool-size-max\" : \"%d\",", maxActorCount));
    executorConfigBuilder.append("\"task-queue-size\" : \"-1\",");
    executorConfigBuilder.append("\"task-queue-type\" : \"linked\",");
    executorConfigBuilder.append("\"allow-core-timeout\" : \"on\"");
    executorConfigBuilder.append("}");

    configBuilder.append(executorConfigBuilder.toString());
    configBuilder.append("}}}}");

    Config mergedConfig = ConfigFactory.load(ConfigFactory.parseString(configBuilder.toString()).withFallback(ConfigFactory.load()));
    return ActorSystem.create(String.format("PerformanceAsync%s", systemId), mergedConfig);
}

As you can see I was primarily interested in tweaking the dispatcher.

来源：https://stackoverflow.com/questions/34649527/disable-akka-jvm-exit-on-fatal-error-for-actorsystem-in-java

标签

java

multithreading

akka