[HDFS-4847] hdfs dfs -count of a .snapshot directory fails claiming file does not exist

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 3.0.0-alpha1
• Component/s: snapshots
• Labels: snapshot snapshots
• Assignee: Unassigned
• Reporter: Stephen Chu
• Created: 24/May/13 17:36
• Updated: 12/May/16 18:14
• Resolved: 28/May/13 17:51

Description

I successfully allow snapshots for /tmp and create three snapshots. I verify that the three snapshots are in /tmp/.snapshot.

However, when I attempt hdfs dfs -count /tmp/.snapshot I get a file does not exist exception.

Running -count on /tmp finds /tmp successfully.

schu-mbp:~ schu$ hadoop fs -ls /tmp/.snapshot
2013-05-24 10:27:10,070 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 3 items
drwxr-xr-x   - schu supergroup          0 2013-05-24 10:26 /tmp/.snapshot/s1
drwxr-xr-x   - schu supergroup          0 2013-05-24 10:27 /tmp/.snapshot/s2
drwxr-xr-x   - schu supergroup          0 2013-05-24 10:27 /tmp/.snapshot/s3
schu-mbp:~ schu$ hdfs dfs -count /tmp
2013-05-24 10:27:20,510 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
          12            0                  0 /tmp
schu-mbp:~ schu$ hdfs dfs -count /tmp/.snapshot
2013-05-24 10:27:30,397 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
count: File does not exist: /tmp/.snapshot
schu-mbp:~ schu$ hdfs dfs -count -q /tmp/.snapshot
2013-05-24 10:28:23,252 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
count: File does not exist: /tmp/.snapshot
schu-mbp:~ schu$

In the NN logs, I see:

2013-05-24 10:27:30,857 INFO  [IPC Server handler 6 on 8020] FSNamesystem.audit (FSNamesystem.java:logAuditEvent(6143)) - allowed=true	ugi=schu (auth:SIMPLE)	ip=/127.0.0.1	cmd=getfileinfo	src=/tmp/.snapshot	dst=null	perm=null
2013-05-24 10:27:30,891 ERROR [IPC Server handler 7 on 8020] security.UserGroupInformation (UserGroupInformation.java:doAs(1492)) - PriviledgedActionException as:schu (auth:SIMPLE) cause:java.io.FileNotFoundException: File does not exist: /tmp/.snapshot
2013-05-24 10:27:30,891 INFO  [IPC Server handler 7 on 8020] ipc.Server (Server.java:run(1864)) - IPC Server handler 7 on 8020, call org.apache.hadoop.hdfs.protocol.ClientProtocol.getContentSummary from 127.0.0.1:49738: error: java.io.FileNotFoundException: File does not exist: /tmp/.snapshot
java.io.FileNotFoundException: File does not exist: /tmp/.snapshot
	at org.apache.hadoop.hdfs.server.namenode.FSDirectory.getContentSummary(FSDirectory.java:2267)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getContentSummary(FSNamesystem.java:3188)
	at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.getContentSummary(NameNodeRpcServer.java:829)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getContentSummary(ClientNamenodeProtocolServerSideTranslatorPB.java:726)
	at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:48057)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:527)
	at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1033)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1842)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1838)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:396)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1489)
	at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1836)

Likewise, the hdfs dfs du command fails with the same problem.

Hadoop version:

schu-mbp:~ schu$ hadoop version
Hadoop 3.0.0-SNAPSHOT
Subversion git://github.com/apache/hadoop-common.git -r ccaf5ea09118eedbe17fd3f5b3f0c516221dd613
Compiled by schu on 2013-05-24T04:45Z
From source with checksum ee94d984bcf5cc38ca12a1efedb68fc
This command was run using /Users/schu/hadoop-3.0.0-SNAPSHOT/share/hadoop/common/hadoop-common-3.0.0-SNAPSHOT.jar