Yiqun Lin created HDFS-13671:
--------------------------------
Summary: Namenode deletes large dir slowly caused by
FoldedTreeSet#removeAndGet
Key: HDFS-13671
URL: https://issues.apache.org/jira/browse/HDFS-13671
Project: Hadoop HDFS
Issue Type: Bug
Affects Versions: 3.0.3, 3.1.0
Reporter: Yiqun Lin
NameNode hung when deleting large files/blocks. The stack info:
{code}
"IPC Server handler 4 on 8020" #87 daemon prio=5 os_prio=0
tid=0x00007fb505b27800 nid=0x94c3 runnable [0x00007fa861361000]
java.lang.Thread.State: RUNNABLE
at
org.apache.hadoop.hdfs.util.FoldedTreeSet.compare(FoldedTreeSet.java:474)
at
org.apache.hadoop.hdfs.util.FoldedTreeSet.removeAndGet(FoldedTreeSet.java:849)
at
org.apache.hadoop.hdfs.util.FoldedTreeSet.remove(FoldedTreeSet.java:911)
at
org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo.removeBlock(DatanodeStorageInfo.java:252)
at
org.apache.hadoop.hdfs.server.blockmanagement.BlocksMap.removeBlock(BlocksMap.java:194)
at
org.apache.hadoop.hdfs.server.blockmanagement.BlocksMap.removeBlock(BlocksMap.java:108)
at
org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.removeBlockFromMap(BlockManager.java:3813)
at
org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.removeBlock(BlockManager.java:3617)
at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.removeBlocks(FSNamesystem.java:4270)
at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.deleteInternal(FSNamesystem.java:4244)
at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.deleteInt(FSNamesystem.java:4180)
at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.delete(FSNamesystem.java:4164)
at
org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.delete(NameNodeRpcServer.java:871)
at
org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.delete(AuthorizationProviderProxyClientProtocol.java:311)
at
org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.delete(ClientNamenodeProtocolServerSideTranslatorPB.java:625)
at
org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
at
org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617)
{code}
In the current deletion logic in NameNode, there are mainly two steps:
* Collect INodes and all blocks to be deleted, then delete INodes.
* Remove blocks chunk by chunk in a loop.
Actually the first step should be a more expensive operation and will takes
more time. However, now we always see NN hangs during the remove block
operation.
Looking into this, we introduced a new structure {{FoldedTreeSet}} to have a
better performance in dealing FBR/IBRs. But compared with early implementation
in remove-block logic, {{FoldedTreeSet}} seems more slower since It will take
additional time to balance tree node. When there are large block to be
removed/deleted, it looks bad.
For the get type operations in {{DatanodeStorageInfo}}, we only provide the
{{getBlockIterator}} to return blocks iterator and no other get operation with
specified block. Still we need to use {{FoldedTreeSet}} here? As we know
{{FoldedTreeSet}} is benefit for getting node not deleting/updating node. Maybe
we can revert this to the early implementation.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
