[ https://issues.apache.org/jira/browse/YARN-4024?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16038399#comment-16038399 ]
maobaolong commented on YARN-4024: ---------------------------------- [~zhiguohong] Thanks for this great improvement, i have a minor question. {code:java} public void handle(NodesListManagerEvent event) { RMNode eventNode = event.getNode(); switch (event.getType()) { case NODE_UNUSABLE: LOG.debug(eventNode + " reported unusable"); unusableRMNodesConcurrentSet.add(eventNode); for(RMApp app: rmContext.getRMApps().values()) { if (!app.isAppFinalStateStored()) { this.rmContext .getDispatcher() .getEventHandler() .handle( new RMAppNodeUpdateEvent(app.getApplicationId(), eventNode, RMAppNodeUpdateType.NODE_UNUSABLE)); } } break; case NODE_USABLE: if (unusableRMNodesConcurrentSet.contains(eventNode)) { LOG.debug(eventNode + " reported usable"); unusableRMNodesConcurrentSet.remove(eventNode); } for (RMApp app : rmContext.getRMApps().values()) { if (!app.isAppFinalStateStored()) { this.rmContext .getDispatcher() .getEventHandler() .handle( new RMAppNodeUpdateEvent(app.getApplicationId(), eventNode, RMAppNodeUpdateType.NODE_USABLE)); } } break; default: LOG.error("Ignoring invalid eventtype " + event.getType()); } // remove the cache of normalized hostname if enabled if (resolver instanceof CachedResolver) { ((CachedResolver)resolver).removeFromCache( eventNode.getNodeID().getHost()); } } {code} As the handle method ahead, i see the removeFromCache method will be invoke when handle method is called and no matter whether the event type is valid. Do you think a return in the end of the default block is correct? Or you can removeFromCache definitely when the event type is NODE_UNUSABLE or NODE_USABLE. > YARN RM should avoid unnecessary resolving IP when NMs doing heartbeat > ---------------------------------------------------------------------- > > Key: YARN-4024 > URL: https://issues.apache.org/jira/browse/YARN-4024 > Project: Hadoop YARN > Issue Type: Improvement > Components: resourcemanager > Reporter: Wangda Tan > Assignee: Hong Zhiguo > Fix For: 2.8.0, 3.0.0-alpha1 > > Attachments: YARN-4024-draft.patch, YARN-4024-draft-v2.patch, > YARN-4024-draft-v3.patch, YARN-4024-v4.patch, YARN-4024-v5.patch, > YARN-4024-v6.patch, YARN-4024-v7.patch > > > Currently, YARN RM NodesListManager will resolve IP address every time when > node doing heartbeat. When DNS server becomes slow, NM heartbeat will be > blocked and cannot make progress. -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org