From: Robert Varga <rovarga@cisco.com>
Date: Mon, 30 Mar 2015 13:59:54 +0000 (+0200)
Subject: Tune NotificationRouter wait strategy
X-Git-Tag: release/lithium~327^2
X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=commitdiff_plain;ds=sidebyside;h=f4595138eb29ec95958d9d55b95cc716b2fd692e;hp=a681e6bec3bbd7b536302ee9e083ae04b7f5ebdd;p=controller.git

Tune NotificationRouter wait strategy

CPU traces show we are seeing NotificationRouter spin for more work even
when there are no notifications being generated. Change the strategy so
we end up block the thread after a period of spinning/yielding. The
default spin period is set to 1ms, followed by 30ms of yielding,
followed by a block.

This should provide reasonable throughput on notification-heavy
workloads as well as not waste a lot of CPU when there are no
notifications.

Change-Id: Ia1de5ff2616392609a0868b9b8ba3bce15baa105
Signed-off-by: Robert Varga <rovarga@cisco.com>
---

diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMNotificationRouter.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMNotificationRouter.java
index b9972fc0a0..e814dd2541 100644
--- a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMNotificationRouter.java
+++ b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMNotificationRouter.java
@@ -17,7 +17,7 @@ import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.lmax.disruptor.EventHandler;
 import com.lmax.disruptor.InsufficientCapacityException;
-import com.lmax.disruptor.SleepingWaitStrategy;
+import com.lmax.disruptor.PhasedBackoffWaitStrategy;
 import com.lmax.disruptor.WaitStrategy;
 import com.lmax.disruptor.dsl.Disruptor;
 import com.lmax.disruptor.dsl.ProducerType;
@@ -50,7 +50,7 @@ import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  */
 public final class DOMNotificationRouter implements AutoCloseable, DOMNotificationPublishService, DOMNotificationService {
     private static final ListenableFuture<Void> NO_LISTENERS = Futures.immediateFuture(null);
-    private static final WaitStrategy DEFAULT_STRATEGY = new SleepingWaitStrategy();
+    private static final WaitStrategy DEFAULT_STRATEGY = PhasedBackoffWaitStrategy.withLock(1L, 30L, TimeUnit.MILLISECONDS);
     private static final EventHandler<DOMNotificationRouterEvent> DISPATCH_NOTIFICATIONS = new EventHandler<DOMNotificationRouterEvent>() {
         @Override
         public void onEvent(final DOMNotificationRouterEvent event, final long sequence, final boolean endOfBatch) throws Exception {