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Apache Spark commented on SPARK-31632: -------------------------------------- User 'xccui' has created a pull request for this issue: https://github.com/apache/spark/pull/28444 > The ApplicationInfo in KVStore may be accessed before it's prepared > ------------------------------------------------------------------- > > Key: SPARK-31632 > URL: https://issues.apache.org/jira/browse/SPARK-31632 > Project: Spark > Issue Type: Bug > Components: Spark Core, Web UI > Affects Versions: 3.0.0 > Reporter: Xingcan Cui > Priority: Minor > > While starting some local tests, I occasionally encountered the following > exceptions for Web UI. > {noformat} > 23:00:29.845 WARN org.eclipse.jetty.server.HttpChannel: /jobs/ > java.util.NoSuchElementException > at java.util.Collections$EmptyIterator.next(Collections.java:4191) > at > org.apache.spark.util.kvstore.InMemoryStore$InMemoryIterator.next(InMemoryStore.java:467) > at > org.apache.spark.status.AppStatusStore.applicationInfo(AppStatusStore.scala:39) > at org.apache.spark.ui.jobs.AllJobsPage.render(AllJobsPage.scala:266) > at org.apache.spark.ui.WebUI.$anonfun$attachPage$1(WebUI.scala:89) > at org.apache.spark.ui.JettyUtils$$anon$1.doGet(JettyUtils.scala:80) > at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) > at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) > at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:873) > at > org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1623) > at > org.apache.spark.ui.HttpSecurityFilter.doFilter(HttpSecurityFilter.scala:95) > at > org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610) > at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540) > at > org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) > at > org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345) > at > org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) > at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480) > at > org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) > at > org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247) > at > org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) > at > org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:753) > at > org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:220) > at > org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) > at org.eclipse.jetty.server.Server.handle(Server.java:505) > at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370) > at > org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267) > at > org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305) > at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103) > at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117) > at > org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:698) > at > org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:804) > at java.lang.Thread.run(Thread.java:748){noformat} > *Reason* > That is because {{AppStatusStore.applicationInfo()}} accesses an empty view > (iterator) returned by {{InMemoryStore}}. > AppStatusStore > {code:java} > def applicationInfo(): v1.ApplicationInfo = { > store.view(classOf[ApplicationInfoWrapper]).max(1).iterator().next().info > } > {code} > InMemoryStore > {code:java} > public <T> KVStoreView<T> view(Class<T> type){ > InstanceList<T> list = inMemoryLists.get(type); > return list != null ? list.view() : emptyView(); > } > {code} > During the initialization of {{SparkContext}}, it first starts the Web UI > (SparkContext: L475 _ui.foreach(_.bind())) and then setup the > {{LiveListenerBus}} thread (SparkContext: L608 > {{setupAndStartListenerBus()}}) for dispatching the > {{SparkListenerApplicationStart}} event (which will trigger writing the > requested {{ApplicationInfo}} to {{InMemoryStore}}). > *Solution* > Since the {{applicationInfo()}} method is expected to always return a valid > {{ApplicationInfo}}, maybe we can add a while-loop-check here to guarantee > the availability of {{ApplicationInfo}}. > {code:java} > def applicationInfo(): v1.ApplicationInfo = { > var iterator = store.view(classOf[ApplicationInfoWrapper]).max(1).iterator() > while (!iterator.hasNext){ > Thread.sleep(20) > iterator = store.view(classOf[ApplicationInfoWrapper]).max(1).iterator() > } > iterator.next().info > } > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org