[ https://issues.apache.org/jira/browse/CASSANDRA-13137?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sotirios Delimanolis updated CASSANDRA-13137: --------------------------------------------- Summary: nodetool disablethrift deadlocks if THsHaDisruptorServer is stopped while a request is being processed (was: nodetool disablethrift deadlocks if THsHaDisruptorServer is stopped while a read is going on) > nodetool disablethrift deadlocks if THsHaDisruptorServer is stopped while a > request is being processed > ------------------------------------------------------------------------------------------------------ > > Key: CASSANDRA-13137 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13137 > Project: Cassandra > Issue Type: Bug > Components: Core > Environment: 2.2.9 > Reporter: Sotirios Delimanolis > > We are using Thrift with {{rpc_server_type}} set to {{hsha}}. This creates a > {{THsHaDisruptorServer}} which is a subclass of > [{{TDisruptorServer}}|https://github.com/xedin/disruptor_thrift_server/blob/master/src/main/java/com/thinkaurelius/thrift/TDisruptorServer.java]. > Internally, this spawns {{number_of_cores}} number of selector threads. Each > gets a {{RingBuffer}} and {{rpc_max_threads / cores}} number of worker > threads (the {{RPC-Thread}} threads). As the server starts receiving > requests, each selector thread adds events to its {{RingBuffer}} and the > worker threads process them. > The _events_ are > [{{Message}}|https://github.com/xedin/disruptor_thrift_server/blob/master/src/main/java/com/thinkaurelius/thrift/Message.java] > instances, which have preallocated buffers for eventual IO. > When the thrift server starts up, the corresponding {{ThriftServerThread}} > joins on the selector threads, waiting for them to die. It then iterates > through all the {{SelectorThread}} objects and calls their {{shutdown}} > method which attempts to drain their corresponding {{RingBuffer}}. The [drain > ({{drainAndHalt}})|https://github.com/LMAX-Exchange/disruptor/blob/master/src/main/java/com/lmax/disruptor/WorkerPool.java#L147] > works by letting the worker pool "consumer" threads catch up to the > "producer" index, ie. the selector thread. > When we execute a {{nodetool disablethrift}}, it attempts to {{stop}} the > {{THsHaDisruptorServer}}. That works by setting a {{stopped}} flag to > {{true}}. When the selector threads see that, they break from their > {{select()}} loop, and clean up their resources, ie. the {{Message}} objects > they've created and their buffers. *However*, if one of those {{Message}} > objects is currently being used by a worker pool thread to process a request, > if it calls [this piece of > code|https://github.com/xedin/disruptor_thrift_server/blob/master/src/main/java/com/thinkaurelius/thrift/Message.java#L317], > you'll get the following {{NullPointerException}} > {noformat} > Jan 18, 2017 6:28:50 PM com.lmax.disruptor.FatalExceptionHandler > handleEventException > SEVERE: Exception processing: 633124 > com.thinkaurelius.thrift.Message$Invocation@25c9fbeb > java.lang.NullPointerException > at > com.thinkaurelius.thrift.Message.getInputTransport(Message.java:338) > at com.thinkaurelius.thrift.Message.invoke(Message.java:308) > at > com.thinkaurelius.thrift.Message$Invocation.execute(Message.java:90) > at > com.thinkaurelius.thrift.TDisruptorServer$InvocationHandler.onEvent(TDisruptorServer.java:695) > at > com.thinkaurelius.thrift.TDisruptorServer$InvocationHandler.onEvent(TDisruptorServer.java:689) > at com.lmax.disruptor.WorkProcessor.run(WorkProcessor.java:112) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:745) > {noformat} > That fails because it tries to dereference one of the {{Message}} "cleaned > up", ie. {{null}}, buffers. > Because that call is outside the {{try}} block, the exception escapes and > basically kills the worker pool thread. This has the side effect of > "discarding" one of the consumers of a selector's {{RingBuffer}}. > *That* has the side effect of preventing the {{ThriftServerThread}} from > draining the {{RingBuffer}} (and dying) since the consumers never catch up to > the stopped producer. And that finally has the effect of preventing the > {{nodetool disablethrift}} from proceeding since it's trying to {{join}} the > {{ThriftServerThread}}. Deadlock! > The {{ThriftServerThread}} thread looks like > {noformat} > "Thread-1" #2234 prio=5 os_prio=0 tid=0x00007f4ae6ff1000 nid=0x2eb6 runnable > [0x00007f4729174000] > java.lang.Thread.State: RUNNABLE > at java.lang.Thread.yield(Native Method) > at com.lmax.disruptor.WorkerPool.drainAndHalt(WorkerPool.java:147) > at > com.thinkaurelius.thrift.TDisruptorServer$SelectorThread.shutdown(TDisruptorServer.java:633) > at > com.thinkaurelius.thrift.TDisruptorServer.gracefullyShutdownInvokerPool(TDisruptorServer.java:301) > at > com.thinkaurelius.thrift.TDisruptorServer.waitForShutdown(TDisruptorServer.java:280) > at > org.apache.thrift.server.AbstractNonblockingServer.serve(AbstractNonblockingServer.java:95) > at > org.apache.cassandra.thrift.ThriftServer$ThriftServerThread.run(ThriftServer.java:137) > {noformat} > The {{nodetool disablethrift}} thread looks like > {noformat} > "RMI TCP Connection(18183)-127.0.0.1" #12121 daemon prio=5 os_prio=0 > tid=0x00007f4ac2c61000 nid=0x5805 in Object.wait() [0x00007f4aab7ec000] > java.lang.Thread.State: WAITING (on object monitor) > at java.lang.Object.wait(Native Method) > at java.lang.Thread.join(Thread.java:1249) > - locked <0x000000055d3cb010> (a > org.apache.cassandra.thrift.ThriftServer$ThriftServerThread) > at java.lang.Thread.join(Thread.java:1323) > at org.apache.cassandra.thrift.ThriftServer.stop(ThriftServer.java:70) > - locked <0x000000055bffb5e0> (a > org.apache.cassandra.thrift.ThriftServer) > at > org.apache.cassandra.service.StorageService.stopRPCServer(StorageService.java:337) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:498) > at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71) > at sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:498) > at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275) > at > com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112) > at > com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46) > at > com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237) > at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138) > at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252) > at > com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) > at > com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) > at > javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) > at > javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76) > at > javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) > at > javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401) > at > javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) > at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:498) > at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:324) > at sun.rmi.transport.Transport$1.run(Transport.java:200) > at sun.rmi.transport.Transport$1.run(Transport.java:197) > at java.security.AccessController.doPrivileged(Native Method) > at sun.rmi.transport.Transport.serviceCall(Transport.java:196) > at > sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568) > at > sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826) > at > sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683) > at > sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$1/1038375559.run(Unknown > Source) > at java.security.AccessController.doPrivileged(Native Method) > at > sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:745) > {noformat} > Most of the code involved isn't part of Cassandra source, but it's an > external dependency that should be fixed. -- This message was sent by Atlassian JIRA (v6.3.4#6332)