Hi, "java.io.IOException: Connection reset by peer" is usually thrown if the remote peer terminates the connection. So the interesting bit would be who's requesting static files from Flink. So far we serve the web frontend and the log and stdout files via the StaticFileServerHandler. Maybe it's DC/OS itself for some reason? This error should, however, not influence Flink itself.
Cheers, Till On Thu, Feb 8, 2018 at 12:36 PM, Lasse Nedergaard <lassenederga...@gmail.com > wrote: > And We see the same too > > Med venlig hilsen / Best regards > Lasse Nedergaard > > > Den 8. feb. 2018 kl. 11.58 skrev Stavros Kontopoulos < > st.kontopou...@gmail.com>: > > We see the same issue here (2): > 2018-02-08 10:55:11,447 ERROR > org.apache.flink.runtime.webmonitor.files.StaticFileServerHandler > - Caught exception > java.io.IOException: Connection reset by peer > > Stavros > > On Sat, Jan 13, 2018 at 9:59 PM, Eron Wright <eronwri...@gmail.com> wrote: > >> Hello Dongwon, >> >> Flink doesn't support a 'unique host' constraint at this time; it simply >> accepts adequate offers without any such consideration. Flink does >> support a 'host attributes' constraint to filter certain hosts, but that's >> not applicable here. >> >> Under the hood, Flink uses a library called Netflix Fenzo to optimize >> placement, and a uniqueness constraint could be added by more deeply >> leveraging Fenzo's constraint system. You mentioned that you're trying to >> make good use of your GPU resources, which could also be achieved by >> treating GPU as a scalar resource (similar to how memory and cores are >> treated). Mesos does support that, but Fenzo may require some >> enhancement. So, these are two potential ways to enhance Flink to support >> your scenario. I'm happy to help; reach out to me. >> >> The obvious, ugly workaround is to configure your TMs to be large enough >> to consume the whole host. >> >> Eron >> >> >> >> >> >> On Thu, Jan 11, 2018 at 7:18 AM, Gary Yao <g...@data-artisans.com> wrote: >> >>> Hi Dongwon, >>> >>> I am not familiar with the deployment on DC/OS. However, Eron Wright and >>> Jörg >>> Schad (cc'd), who have worked on the Mesos integration, might be able to >>> help >>> you. >>> >>> Best, >>> Gary >>> >>> On Tue, Jan 9, 2018 at 10:29 AM, Dongwon Kim <eastcirc...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> I've launched JobManager and TaskManager on DC/OS successfully. >>>> Now I have two new issues: >>>> >>>> 1) All TaskManagers are scheduled on a single node. >>>> - Is it intended to maximize data locality and minimize network >>>> communication cost? >>>> - Is there an option in Flink to adjust the behavior of JobManager when >>>> it considers multiple resource offers from different Mesos agents? >>>> - I want to schedule TaskManager processes on different GPU servers so >>>> that each TaskManger process can use its own GPU cards exclusively. >>>> - Below is a part of JobManager log that is occurring while JobManager >>>> is negotiating resources with the Mesos master: >>>> >>>> 2018-01-09 07:34:54,872 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosJobManager - >>>> JobManager akka.tcp://flink@dnn-g08-233:18026/user/jobmanager was granted >>>> leadership with leader session ID >>>> Some(00000000-0000-0000-0000-000000000000). >>>> 2018-01-09 07:34:55,889 INFO >>>> org.apache.flink.mesos.scheduler.ConnectionMonitor - Connecting >>>> to Mesos... >>>> 2018-01-09 07:34:55,962 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Trying to associate with JobManager leader >>>> akka.tcp://flink@dnn-g08-233:18026/user/jobmanager >>>> 2018-01-09 07:34:55,977 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Resource Manager associating with leading JobManager >>>> Actor[akka://flink/user/jobmanager#-1481183359] - leader session >>>> 00000000-0000-0000-0000-000000000000 >>>> 2018-01-09 07:34:56,479 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Scheduling Mesos task taskmanager-00001 with (10240.0 MB, 8.0 cpus). >>>> 2018-01-09 07:34:56,481 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Scheduling Mesos task taskmanager-00002 with (10240.0 MB, 8.0 cpus). >>>> 2018-01-09 07:34:56,481 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Scheduling Mesos task taskmanager-00003 with (10240.0 MB, 8.0 cpus). >>>> 2018-01-09 07:34:56,481 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Scheduling Mesos task taskmanager-00004 with (10240.0 MB, 8.0 cpus). >>>> 2018-01-09 07:34:56,481 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Scheduling Mesos task taskmanager-00005 with (10240.0 MB, 8.0 cpus). >>>> 2018-01-09 07:34:56,483 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Now >>>> gathering offers for at least 5 task(s). >>>> 2018-01-09 07:34:56,484 INFO >>>> org.apache.flink.mesos.scheduler.ConnectionMonitor - Connected >>>> to Mesos as framework ID 59b85b42-a4a2-4632-9578-9e480585ecdc-0004. >>>> 2018-01-09 07:34:56,690 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Received >>>> offer(s) of 606170.0 MB, 234.2 cpus: >>>> 2018-01-09 07:34:56,692 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2174 from 50.1.100.233 of 111186.0 >>>> MB, 45.9 cpus for [*] >>>> 2018-01-09 07:34:56,692 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2175 from 50.1.100.235 of 123506.0 >>>> MB, 47.3 cpus for [*] >>>> 2018-01-09 07:34:56,692 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2176 from 50.1.100.234 of 124530.0 >>>> MB, 46.6 cpus for [*] >>>> 2018-01-09 07:34:56,692 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2177 from 50.1.100.231 of 123474.0 >>>> MB, 47.2 cpus for [*] >>>> 2018-01-09 07:34:56,693 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2178 from 50.1.100.232 of 123474.0 >>>> MB, 47.2 cpus for [*] >>>> 2018-01-09 07:34:57,711 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Processing >>>> 5 task(s) against 5 new offer(s) plus outstanding offers. >>>> 2018-01-09 07:34:57,726 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Resources >>>> considered: (note: expired offers not deducted from below) >>>> 2018-01-09 07:34:57,727 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 50.1.100.234 has 124530.0 MB, 46.6 cpus >>>> 2018-01-09 07:34:57,728 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 50.1.100.235 has 123506.0 MB, 47.3 cpus >>>> 2018-01-09 07:34:57,728 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 50.1.100.232 has 123474.0 MB, 47.2 cpus >>>> 2018-01-09 07:34:57,728 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 50.1.100.233 has 111186.0 MB, 45.9 cpus >>>> 2018-01-09 07:34:57,728 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 50.1.100.231 has 123474.0 MB, 47.2 cpus >>>> 2018-01-09 07:34:58,069 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Launching Mesos task taskmanager-00005 on host 50.1.100.231. >>>> 2018-01-09 07:34:58,069 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Launched 5 >>>> task(s) on 50.1.100.231 using 1 offer(s): >>>> 2018-01-09 07:34:58,070 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Launching Mesos task taskmanager-00002 on host 50.1.100.231. >>>> 2018-01-09 07:34:58,070 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Launching Mesos task taskmanager-00003 on host 50.1.100.231. >>>> 2018-01-09 07:34:58,070 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Launching Mesos task taskmanager-00004 on host 50.1.100.231. >>>> 2018-01-09 07:34:58,070 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - Launching Mesos task taskmanager-00001 on host 50.1.100.231. >>>> 2018-01-09 07:34:58,070 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - >>>> 59b85b42-a4a2-4632-9578-9e480585ecdc-O2177 >>>> 2018-01-09 07:34:58,071 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - No longer >>>> gathering offers; all requests fulfilled. >>>> 2018-01-09 07:34:58,072 INFO com.netflix.fenzo.TaskScheduler >>>> - Expiring all leases >>>> 2018-01-09 07:34:58,072 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Declined >>>> offer 59b85b42-a4a2-4632-9578-9e480585ecdc-O2176 from 50.1.100.234 of >>>> 124530.0 MB, 46.6 cpus. >>>> 2018-01-09 07:34:58,073 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Declined >>>> offer 59b85b42-a4a2-4632-9578-9e480585ecdc-O2175 from 50.1.100.235 of >>>> 123506.0 MB, 47.3 cpus. >>>> 2018-01-09 07:34:58,073 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Declined >>>> offer 59b85b42-a4a2-4632-9578-9e480585ecdc-O2178 from 50.1.100.232 of >>>> 123474.0 MB, 47.2 cpus. >>>> 2018-01-09 07:34:58,074 INFO >>>> org.apache.flink.mesos.scheduler.LaunchCoordinator - Declined >>>> offer 59b85b42-a4a2-4632-9578-9e480585ecdc-O2174 from 50.1.100.233 of >>>> 111186.0 MB, 45.9 cpus. >>>> 2018-01-09 07:35:05,868 INFO org.apache.flink.mesos.scheduler.TaskMonitor >>>> - Mesos task taskmanager-00005 is running. >>>> 2018-01-09 07:35:06,103 INFO org.apache.flink.mesos.scheduler.TaskMonitor >>>> - Mesos task taskmanager-00001 is running. >>>> 2018-01-09 07:35:06,111 INFO org.apache.flink.mesos.scheduler.TaskMonitor >>>> - Mesos task taskmanager-00004 is running. >>>> 2018-01-09 07:35:06,116 INFO org.apache.flink.mesos.scheduler.TaskMonitor >>>> - Mesos task taskmanager-00002 is running. >>>> 2018-01-09 07:35:06,119 INFO org.apache.flink.mesos.scheduler.TaskMonitor >>>> - Mesos task taskmanager-00003 is running. >>>> 2018-01-09 07:35:14,377 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - TaskManager taskmanager-00003 has started. >>>> 2018-01-09 07:35:14,380 INFO >>>> org.apache.flink.runtime.instance.InstanceManager - Registered >>>> TaskManager at DNN-G08-231 >>>> (akka.tcp://flink@dnn-g08-231:1027/user/taskmanager) as >>>> b94277c8ad550eeef5364947e4330c00. Current number of registered hosts is 1. >>>> Current number of alive task slots is 8. >>>> 2018-01-09 07:35:14,389 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - TaskManager taskmanager-00004 has started. >>>> 2018-01-09 07:35:14,389 INFO >>>> org.apache.flink.runtime.instance.InstanceManager - Registered >>>> TaskManager at DNN-G08-231 >>>> (akka.tcp://flink@dnn-g08-231:1033/user/taskmanager) as >>>> e0183a5317b331b90496049b1893c922. Current number of registered hosts is 2. >>>> Current number of alive task slots is 16. >>>> 2018-01-09 07:35:14,462 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - TaskManager taskmanager-00001 has started. >>>> 2018-01-09 07:35:14,462 INFO >>>> org.apache.flink.runtime.instance.InstanceManager - Registered >>>> TaskManager at DNN-G08-231 >>>> (akka.tcp://flink@dnn-g08-231:1029/user/taskmanager) as >>>> 8d85b49d4118514552fcad3b98fef3e2. Current number of registered hosts is 3. >>>> Current number of alive task slots is 24. >>>> 2018-01-09 07:35:14,465 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - TaskManager taskmanager-00005 has started. >>>> 2018-01-09 07:35:14,465 INFO >>>> org.apache.flink.runtime.instance.InstanceManager - Registered >>>> TaskManager at DNN-G08-231 >>>> (akka.tcp://flink@dnn-g08-231:1031/user/taskmanager) as >>>> b740607fb2e88bcfc275498bb54ed9fd. Current number of registered hosts is 4. >>>> Current number of alive task slots is 32. >>>> 2018-01-09 07:35:14,560 INFO >>>> org.apache.flink.mesos.runtime.clusterframework.MesosFlinkResourceManager >>>> - TaskManager taskmanager-00002 has started. >>>> 2018-01-09 07:35:14,560 INFO >>>> org.apache.flink.runtime.instance.InstanceManager - Registered >>>> TaskManager at DNN-G08-231 >>>> (akka.tcp://flink@dnn-g08-231:1025/user/taskmanager) as >>>> 95433440f37ea1790e7ef9309f110fe4. Current number of registered hosts is 5. >>>> Current number of alive task slots is 40. >>>> >>>> >>>> >>>> 2) After the TaskManagers are started, the following lines are repeated >>>> in the JobManage log every second: >>>> >>>> 2018-01-09 07:36:51,080 ERROR >>>> org.apache.flink.runtime.rest.handler.legacy.files.StaticFileServerHandler >>>> - Caught exception >>>> java.io.IOException: Connection reset by peer >>>> at sun.nio.ch.FileDispatcherImpl.read0(Native Method) >>>> at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39) >>>> at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223) >>>> at sun.nio.ch.IOUtil.read(IOUtil.java:192) >>>> at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.UnpooledUnsafeDirectByteBuf.setBytes(UnpooledUnsafeDirectByteBuf.java:447) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:881) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:241) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:119) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) >>>> at java.lang.Thread.run(Thread.java:748) >>>> 2018-01-09 07:37:43,600 ERROR >>>> org.apache.flink.runtime.rest.handler.legacy.files.StaticFileServerHandler >>>> - Caught exception >>>> java.io.IOException: Connection reset by peer >>>> at sun.nio.ch.FileDispatcherImpl.read0(Native Method) >>>> at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39) >>>> at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223) >>>> at sun.nio.ch.IOUtil.read(IOUtil.java:192) >>>> at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.UnpooledUnsafeDirectByteBuf.setBytes(UnpooledUnsafeDirectByteBuf.java:447) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:881) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:241) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:119) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) >>>> at java.lang.Thread.run(Thread.java:748) >>>> 2018-01-09 07:38:43,619 ERROR >>>> org.apache.flink.runtime.rest.handler.legacy.files.StaticFileServerHandler >>>> - Caught exception >>>> java.io.IOException: Connection reset by peer >>>> at sun.nio.ch.FileDispatcherImpl.read0(Native Method) >>>> at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39) >>>> at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223) >>>> at sun.nio.ch.IOUtil.read(IOUtil.java:192) >>>> at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.UnpooledUnsafeDirectByteBuf.setBytes(UnpooledUnsafeDirectByteBuf.java:447) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:881) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:241) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:119) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) >>>> at java.lang.Thread.run(Thread.java:748) >>>> 2018-01-09 07:39:43,630 ERROR >>>> org.apache.flink.runtime.rest.handler.legacy.files.StaticFileServerHandler >>>> - Caught exception >>>> java.io.IOException: Connection reset by peer >>>> at sun.nio.ch.FileDispatcherImpl.read0(Native Method) >>>> at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39) >>>> at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223) >>>> at sun.nio.ch.IOUtil.read(IOUtil.java:192) >>>> at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.UnpooledUnsafeDirectByteBuf.setBytes(UnpooledUnsafeDirectByteBuf.java:447) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:881) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:241) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:119) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:111) >>>> at >>>> org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) >>>> at java.lang.Thread.run(Thread.java:748) >>>> >>>> - Can I ignore this exception? or there's something I should fix up? >>>> >>>> Best, >>>> >>>> - Dongwon >>>> >>>> >>> >> >
