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  1. ZooKeeper
  2. ZOOKEEPER-515

Zookeeper quorum didn't provide service when restart after an "Out of memory" crash

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Invalid
    • Affects Version/s: 3.2.0
    • Fix Version/s: 3.5.0
    • Component/s: server
    • Labels:
      None
    • Environment:

      Linux 2.6.9-52bs-4core #2 SMP Wed Jan 16 14:44:08 EST 2008 x86_64 x86_64 x86_64 GNU/Linux
      Jdk: 1.6.0_14

      Description

      The Zookeeper quorum, containing 5 servers, didn't provide service when restart after an "Out of memory" crash.

      It happened as following:
      1. we built a Zookeeper quorum which contained 5 servers, say 1, 3, 4, 5, 6 (have no 2), and 6 was the leader.
      2. we created 18 threads on 6 different servers to set and get data from a znode in the Zookeeper at the same time. The size of the data is 1MB. The test threads did their job as fast as possible, no pause between two operation, and they repeated the setting and getting 4000 times.
      3. the Zookeeper leader crashed about 10 mins after the test threads started. The leader printed out the log:

      2009-08-25 12:00:12,301 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x523
      4223c2dc00b5 due to java.io.IOException: Read error
      2009-08-25 12:00:12,318 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x523
      4223c2dc00b6 due to java.io.IOException: Read error
      2009-08-25 12:03:44,086 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x523
      4223c2dc00b8 due to java.io.IOException: Read error
      2009-08-25 12:04:53,757 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x523
      4223c2dc00b7 due to java.io.IOException: Read error
      2009-08-25 12:15:45,151 - FATAL [SyncThread:0:SyncRequestProcessor@131] - Severe unrecoverable error, exiting
      java.lang.OutOfMemoryError: Java heap space
      at java.util.Arrays.copyOf(Arrays.java:2786)
      at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:71)
      at java.io.DataOutputStream.writeInt(DataOutputStream.java:180)
      at org.apache.jute.BinaryOutputArchive.writeInt(BinaryOutputArchive.java:55)
      at org.apache.zookeeper.txn.SetDataTxn.serialize(SetDataTxn.java:42)
      at org.apache.zookeeper.server.persistence.Util.marshallTxnEntry(Util.java:262)
      at org.apache.zookeeper.server.persistence.FileTxnLog.append(FileTxnLog.java:154)
      at org.apache.zookeeper.server.persistence.FileTxnSnapLog.append(FileTxnSnapLog.java:268)
      at org.apache.zookeeper.server.SyncRequestProcessor.run(SyncRequestProcessor.java:100)

      It is clear that the leader ran out of memory. then the server 4 was down almost at the same time, and printed out the log:
      2009-08-25 12:15:45,995 - ERROR [FollowerRequestProcessor:3:FollowerRequestProcessor@91] - Unexpected exception causing
      exit
      java.net.SocketException: Connection reset
      at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:96)
      at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
      at java.io.BufferedOutputStream.write(BufferedOutputStream.java:105)
      at java.io.DataOutputStream.write(DataOutputStream.java:90)
      at java.io.FilterOutputStream.write(FilterOutputStream.java:80)
      at org.apache.jute.BinaryOutputArchive.writeBuffer(BinaryOutputArchive.java:119)
      at org.apache.zookeeper.server.quorum.QuorumPacket.serialize(QuorumPacket.java:51)
      at org.apache.jute.BinaryOutputArchive.writeRecord(BinaryOutputArchive.java:123)
      at org.apache.zookeeper.server.quorum.Follower.writePacket(Follower.java:97)
      at org.apache.zookeeper.server.quorum.Follower.request(Follower.java:399)
      at org.apache.zookeeper.server.quorum.FollowerRequestProcessor.run(FollowerRequestProcessor.java:86)
      2009-08-25 12:15:45,996 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x423
      4ab894330075 due to java.net.SocketException: Broken pipe
      2009-08-25 12:15:45,996 - FATAL [SyncThread:3:SyncRequestProcessor@131] - Severe unrecoverable error, exiting
      java.net.SocketException: Broken pipe
      at java.net.SocketOutputStream.socketWrite0(Native Method)
      at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
      at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
      at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
      at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
      at org.apache.zookeeper.server.quorum.Follower.writePacket(Follower.java:100)
      at org.apache.zookeeper.server.quorum.SendAckRequestProcessor.flush(SendAckRequestProcessor.java:52)
      at org.apache.zookeeper.server.SyncRequestProcessor.flush(SyncRequestProcessor.java:147)
      at org.apache.zookeeper.server.SyncRequestProcessor.run(SyncRequestProcessor.java:92)
      2009-08-25 12:15:45,995 - WARN [QuorumPeer:/0.0.0.0:2181:Follower@309] - Exception when following the leader
      java.net.SocketException: Broken pipe
      at java.net.SocketOutputStream.socketWrite0(Native Method)
      at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
      at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
      at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
      at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
      at org.apache.zookeeper.server.quorum.Follower.writePacket(Follower.java:100)
      at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:256)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:498)
      2009-08-25 12:15:46,022 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 12:15:46,022 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 12:15:46,023 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running

      It was really strange that when the 2 server down, the other three servers cannot provide service any more, the 'stat' command all leaded to "ZooKeeperServer not running".

      4. I restarted the server 6(the former leader) and the server 4. But the service didn't come back. All the five servers printed "ZookeeperServer not running". The server 6 printed the logs:

      2009-08-25 14:02:15,395 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:02:27,703 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: Responded to info probe
      2009-08-25 14:02:28,733 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:02:42,070 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:02:55,407 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:03:08,744 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:03:22,080 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:03:29,396 - ERROR [main:Util@238] - Last transaction was partial.
      2009-08-25 14:03:35,417 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:03:48,761 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running

      The server 4 printed logs like:

      2009-08-25 14:03:48,747 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:04:02,091 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:04:15,427 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:04:17,816 - WARN [QuorumPeer:/0.0.0.0:2181:Follower@164] - Unexpected exception, tries=0
      java.net.ConnectException: Connection refused
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
      at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
      at java.net.Socket.connect(Socket.java:525)
      at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:156)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:498)
      2009-08-25 14:04:18,820 - WARN [QuorumPeer:/0.0.0.0:2181:Follower@164] - Unexpected exception, tries=1
      java.net.ConnectException: Connection refused
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
      at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
      at java.net.Socket.connect(Socket.java:525)
      at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:156)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:498)
      2009-08-25 14:04:19,823 - WARN [QuorumPeer:/0.0.0.0:2181:Follower@164] - Unexpected exception, tries=2
      java.net.ConnectException: Connection refused
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
      at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
      at java.net.Socket.connect(Socket.java:525)
      at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:156)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:498)
      2009-08-25 14:04:28,764 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:04:42,101 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running

      the server 1, 3, 5 printed out the logs like:

      2009-08-25 14:01:35,396 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: ZooKeeperServer not running
      2009-08-25 14:01:36,554 - WARN [QuorumPeer:/0.0.0.0:2181:LeaderElection@194] - Ignoring exception while looking for lea
      der
      java.net.SocketTimeoutException: Receive timed out
      at java.net.PlainDatagramSocketImpl.receive0(Native Method)
      at java.net.PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:136)
      at java.net.DatagramSocket.receive(DatagramSocket.java:712)
      at org.apache.zookeeper.server.quorum.LeaderElection.lookForLeader(LeaderElection.java:170)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:488)
      2009-08-25 14:01:37,758 - WARN [QuorumPeer:/0.0.0.0:2181:LeaderElection@194] - Ignoring exception while looking for lea
      der
      java.net.SocketTimeoutException: Receive timed out
      at java.net.PlainDatagramSocketImpl.receive0(Native Method)
      at java.net.PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:136)
      at java.net.DatagramSocket.receive(DatagramSocket.java:712)
      at org.apache.zookeeper.server.quorum.LeaderElection.lookForLeader(LeaderElection.java:170)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:488)
      2009-08-25 14:01:37,865 - WARN [QuorumPeer:/0.0.0.0:2181:Follower@164] - Unexpected exception, tries=0
      java.net.ConnectException: Connection refused
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
      at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
      at java.net.Socket.connect(Socket.java:525)
      at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:156)
      at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:498)
      2009-08-25 14:01:38,289 - WARN [NIOServerCxn.Factory:2181:NIOServerCnxn@497] - Exception causing close of session 0x0 d
      ue to java.io.IOException: Responded to info probe

      my zoo.cfg is like:
      tickTime=2000
      dataDir=./status/
      clientPort=2181
      initLimit=10
      syncLimit=2
      server.1=10.81.11.107:2888:3888
      server.2=10.81.11.106:2888:3888
      server.3=10.81.11.89:2888:3888
      server.4=10.81.11.99:2888:3888
      server.5=10.81.11.79:2888:3888

      Several questions:
      1. Why the leader selection failed after the restart?
      2. Is the size of data too big to be processed properly?
      3. How can I recover from this situation? Can I just remove the version-2 directory on server 6(the former leader) and restart the server?

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            • Assignee:
              Unassigned
              Reporter:
              creatstar Qian Ye
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              • Created:
                Updated:
                Resolved: