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POdisruptor performance issues when using two layers of multiple handlers in a pool
 

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  1. POdisruptor performance issues when using two layers of multiple handlers in a pool
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    <p>i'm trying to use disruptor to process messages. i need two phases of processing. i.e. two groups of handlers working in a worker pool like this (i guess):</p> <pre><code>disruptor. handleEventsWithWorkerPool( firstPhaseHandlers) .thenHandleEventsWithWorkerPool( secondPhaseHandlers); </code></pre> <p>when using the code above, if i put more than one worker in each group, the performance deteriorates. meaning tons of CPU wasted for the exact same amount of work. <br/> <br/> i tried to tweak with the ring buffer size (which i already saw has an impact on performance) but in this case it didn't help. so am i doing something wrong, or is this a real problem?</p> <hr> <p>i'm attaching a full demo of the issue.</p> <pre><code>import java.util.ArrayList; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.atomic.AtomicLong; import com.lmax.disruptor.EventFactory; import com.lmax.disruptor.EventTranslatorOneArg; import com.lmax.disruptor.WorkHandler; import com.lmax.disruptor.dsl.Disruptor; final class ValueEvent { private long value; public long getValue() { return value; } public void setValue(long value) { this.value = value; } public final static EventFactory&lt;ValueEvent&gt; EVENT_FACTORY = new EventFactory&lt;ValueEvent&gt;() { public ValueEvent newInstance() { return new ValueEvent(); } }; } class MyWorkHandler implements WorkHandler&lt;ValueEvent&gt; { AtomicLong workDone; public MyWorkHandler (AtomicLong wd) { this.workDone=wd; } public void onEvent(final ValueEvent event) throws Exception { workDone.incrementAndGet(); } } class My2ndPahseWorkHandler implements WorkHandler&lt;ValueEvent&gt; { AtomicLong workDone; public My2ndPahseWorkHandler (AtomicLong wd) { this.workDone=wd; } public void onEvent(final ValueEvent event) throws Exception { workDone.incrementAndGet(); } } class MyEventTranslator implements EventTranslatorOneArg&lt;ValueEvent, Long&gt; { @Override public void translateTo(ValueEvent event, long sequence, Long value) { event.setValue(value); } } public class TwoPhaseDisruptor { static AtomicLong workDone=new AtomicLong(0); @SuppressWarnings("unchecked") public static void main(String[] args) { ExecutorService exec = Executors.newCachedThreadPool(); int numOfHandlersInEachGroup=Integer.parseInt(args[0]); long eventCount=Long.parseLong(args[1]); int ringBufferSize=2 &lt;&lt; (Integer.parseInt(args[2])); Disruptor&lt;ValueEvent&gt; disruptor = new Disruptor&lt;ValueEvent&gt;( ValueEvent.EVENT_FACTORY, ringBufferSize, exec); ArrayList&lt;MyWorkHandler&gt; handlers = new ArrayList&lt;MyWorkHandler&gt;(); for (int i = 0; i &lt; numOfHandlersInEachGroup ; i++) { handlers.add(new MyWorkHandler(workDone)); } ArrayList&lt;My2ndPahseWorkHandler &gt; phase2_handlers = new ArrayList&lt;My2ndPahseWorkHandler &gt;(); for (int i = 0; i &lt; numOfHandlersInEachGroup; i++) { phase2_handlers.add(new My2ndPahseWorkHandler(workDone)); } disruptor .handleEventsWithWorkerPool( handlers.toArray(new WorkHandler[handlers.size()])) .thenHandleEventsWithWorkerPool( phase2_handlers.toArray(new WorkHandler[phase2_handlers.size()])); long s = (System.currentTimeMillis()); disruptor.start(); MyEventTranslator myEventTranslator = new MyEventTranslator(); for (long i = 0; i &lt; eventCount; i++) { disruptor.publishEvent(myEventTranslator, i); } disruptor.shutdown(); exec.shutdown(); System.out.println("time spent "+ (System.currentTimeMillis() - s) + " ms"); System.out.println("amount of work done "+ workDone.get()); } } </code></pre> <p>try running the above example with 1 thread in each group</p> <pre><code>1 100000 7 </code></pre> <p>on my computer it gave </p> <pre><code>time spent 371 ms amount of work done 200000 </code></pre> <p>Then try it with 4 threads in each group</p> <pre><code>4 100000 7 </code></pre> <p>which on my computer gave</p> <pre><code>time spent 9853 ms amount of work done 200000 </code></pre> <p>during the run the CPU is at 100% utilization</p>
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    1. USuser2391480
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    1. COalso - how many cpu cores do you actually have?
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      1. USjasonk
    2. COi think its 4 cores
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      1. POdisruptor performance issues when using two layers of multiple handlers in a pool
      1. USuser2391480
 

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