[
https://issues.apache.org/jira/browse/YARN-7266?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16779609#comment-16779609
]
Eric Yang commented on YARN-7266:
---------------------------------
Without using volatile , the code can be revised to:
{code}
public final class ContextFactory {
private static JAXBContext jaxbContext = null;
private ContextFactory() {
}
public static JAXBContext createContext(Class[] classes,
Map<String, Object> properties) throws Exception {
synchronized (ContextFactory.class) {
if (jaxbContext == null) {
Class spFactory = Class.forName(
"com.sun.xml.internal.bind.v2.ContextFactory");
Method m = spFactory.getMethod("createContext", Class[].class,
Map.class);
jaxbContext = (JAXBContext) m.invoke((Object) null, classes,
properties);
}
}
return jaxbContext;
}
}
{code}
You had it almost right that we want to ensure the locking happen at class
level, and only the conditional check needs to be synchronized. The rest of
the code will return the static non null copy.
> Timeline Server event handler threads locked
> --------------------------------------------
>
> Key: YARN-7266
> URL: https://issues.apache.org/jira/browse/YARN-7266
> Project: Hadoop YARN
> Issue Type: Bug
> Components: ATSv2, timelineserver
> Affects Versions: 2.7.3
> Reporter: Venkata Puneet Ravuri
> Assignee: Prabhu Joseph
> Priority: Major
> Attachments: YARN-7266-0005.patch, YARN-7266-001.patch,
> YARN-7266-002.patch, YARN-7266-003.patch, YARN-7266-004.patch,
> YARN-7266-006.patch
>
>
> Event handlers for Timeline Server seem to take a lock while parsing HTTP
> headers of the request. This is causing all other threads to wait and slowing
> down the overall performance of Timeline server. We have resourcemanager
> metrics enabled to send to timeline server. Because of the high load on
> ResourceManager, the metrics to be sent are getting backlogged and in turn
> increasing heap footprint of Resource Manager (due to pending metrics).
> This is the complete stack trace of a blocked thread on timeline server:-
> "2079644967@qtp-1658980982-4560" #4632 daemon prio=5 os_prio=0
> tid=0x00007f6ba490a000 nid=0x5eb waiting for monitor entry
> [0x00007f6b9142c000]
> java.lang.Thread.State: BLOCKED (on object monitor)
> at
> com.sun.xml.bind.v2.runtime.reflect.opt.AccessorInjector.prepare(AccessorInjector.java:82)
> - waiting to lock <0x00000005c0621860> (a java.lang.Class for
> com.sun.xml.bind.v2.runtime.reflect.opt.AccessorInjector)
> at
> com.sun.xml.bind.v2.runtime.reflect.opt.OptimizedAccessorFactory.get(OptimizedAccessorFactory.java:168)
> at
> com.sun.xml.bind.v2.runtime.reflect.Accessor$FieldReflection.optimize(Accessor.java:282)
> at
> com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.<init>(SingleElementNodeProperty.java:94)
> at sun.reflect.GeneratedConstructorAccessor52.newInstance(Unknown
> Source)
> at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
> Source)
> at java.lang.reflect.Constructor.newInstance(Unknown Source)
> at
> com.sun.xml.bind.v2.runtime.property.PropertyFactory.create(PropertyFactory.java:128)
> at
> com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.<init>(ClassBeanInfoImpl.java:183)
> at
> com.sun.xml.bind.v2.runtime.JAXBContextImpl.getOrCreate(JAXBContextImpl.java:532)
> at
> com.sun.xml.bind.v2.runtime.JAXBContextImpl.getOrCreate(JAXBContextImpl.java:551)
> at
> com.sun.xml.bind.v2.runtime.property.ArrayElementProperty.<init>(ArrayElementProperty.java:112)
> at
> com.sun.xml.bind.v2.runtime.property.ArrayElementNodeProperty.<init>(ArrayElementNodeProperty.java:62)
> at sun.reflect.GeneratedConstructorAccessor19.newInstance(Unknown
> Source)
> at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
> Source)
> at java.lang.reflect.Constructor.newInstance(Unknown Source)
> at
> com.sun.xml.bind.v2.runtime.property.PropertyFactory.create(PropertyFactory.java:128)
> at
> com.sun.xml.bind.v2.runtime.ClassBeanInfoImpl.<init>(ClassBeanInfoImpl.java:183)
> at
> com.sun.xml.bind.v2.runtime.JAXBContextImpl.getOrCreate(JAXBContextImpl.java:532)
> at
> com.sun.xml.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:347)
> at
> com.sun.xml.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1170)
> at
> com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:145)
> at sun.reflect.GeneratedMethodAccessor17.invoke(Unknown Source)
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> at java.lang.reflect.Method.invoke(Unknown Source)
> at javax.xml.bind.ContextFinder.newInstance(Unknown Source)
> at javax.xml.bind.ContextFinder.newInstance(Unknown Source)
> at javax.xml.bind.ContextFinder.find(Unknown Source)
> at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
> at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
> at
> com.sun.jersey.server.wadl.generators.WadlGeneratorJAXBGrammarGenerator.buildModelAndSchemas(WadlGeneratorJAXBGrammarGenerator.java:412)
> at
> com.sun.jersey.server.wadl.generators.WadlGeneratorJAXBGrammarGenerator.createExternalGrammar(WadlGeneratorJAXBGrammarGenerator.java:352)
> at
> com.sun.jersey.server.wadl.WadlBuilder.generate(WadlBuilder.java:115)
> at
> com.sun.jersey.server.impl.wadl.WadlApplicationContextImpl.getApplication(WadlApplicationContextImpl.java:104)
> at
> com.sun.jersey.server.impl.wadl.WadlApplicationContextImpl.getApplication(WadlApplicationContextImpl.java:120)
> at
> com.sun.jersey.server.impl.wadl.WadlMethodFactory$WadlOptionsMethodDispatcher.dispatch(WadlMethodFactory.java:98)
> at
> com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
> at
> com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
> at
> com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
> at
> com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
> at
> com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
> at
> com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
> at
> com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
> at
> com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
> at
> com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
> at
> com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
> at
> com.sun.jersey.spi.container.servlet.ServletContainer.doFilter(ServletContainer.java:886)
> at
> com.sun.jersey.spi.container.servlet.ServletContainer.doFilter(ServletContainer.java:834)
> at
> com.sun.jersey.spi.container.servlet.ServletContainer.doFilter(ServletContainer.java:795)
> at
> com.google.inject.servlet.FilterDefinition.doFilter(FilterDefinition.java:163)
> at
> com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:58)
> at
> com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:118)
> at
> com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:113)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.http.lib.StaticUserWebFilter$StaticUserFilter.doFilter(StaticUserWebFilter.java:96)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.security.authentication.server.AuthenticationFilter.doFilter(AuthenticationFilter.java:594)
> at
> org.apache.hadoop.security.token.delegation.web.DelegationTokenAuthenticationFilter.doFilter(DelegationTokenAuthenticationFilter.java:291)
> at
> org.apache.hadoop.security.authentication.server.AuthenticationFilter.doFilter(AuthenticationFilter.java:553)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.security.http.CrossOriginFilter.doFilter(CrossOriginFilter.java:95)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.http.HttpServer2$QuotingInputFilter.doFilter(HttpServer2.java:1243)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.http.NoCacheFilter.doFilter(NoCacheFilter.java:45)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.apache.hadoop.http.NoCacheFilter.doFilter(NoCacheFilter.java:45)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
> at
> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
> at
> org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
> at
> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
> at
> org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
> at
> org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
> at
> org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
> at
> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
> at org.mortbay.jetty.Server.handle(Server.java:326)
> at
> org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
> at
> org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
> at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
> at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
> at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
> at
> org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
> at
> org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org
