[ACCUMULO-1998] Encrypted WALogs seem to be excessively buffering

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 1.6.0
• Assignee: John Vines
• Reporter: Michael Allen
• Created: 10/Dec/13 15:52
• Updated: 14/Apr/14 21:17
• Resolved: 16/Jan/14 22:45

Description

The reproduction steps around this are a little bit fuzzy but basically we ran a moderate workload against a 1.6.0 server. Encryption happened to be turned on but that doesn't seem to be germane to the problem. After doing a moderate amount of work, Accumulo is refusing to start up, spewing this error over and over to the log:

2013-12-10 10:23:02,529 [tserver.TabletServer] WARN : exception while doing multi-scan 
java.lang.RuntimeException: java.io.IOException: Failed to open hdfs://10.10.1.115:9000/accumulo/tables/!0/table_info/A000042x.rf
	at org.apache.accumulo.tserver.TabletServer$ThriftClientHandler$LookupTask.run(TabletServer.java:1125)
	at org.apache.accumulo.trace.instrument.TraceRunnable.run(TraceRunnable.java:47)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
	at org.apache.accumulo.trace.instrument.TraceRunnable.run(TraceRunnable.java:47)
	at org.apache.accumulo.core.util.LoggingRunnable.run(LoggingRunnable.java:34)
	at java.lang.Thread.run(Thread.java:662)
Caused by: java.io.IOException: Failed to open hdfs://10.10.1.115:9000/accumulo/tables/!0/table_info/A000042x.rf
	at org.apache.accumulo.tserver.FileManager.reserveReaders(FileManager.java:333)
	at org.apache.accumulo.tserver.FileManager.access$500(FileManager.java:58)
	at org.apache.accumulo.tserver.FileManager$ScanFileManager.openFiles(FileManager.java:478)
	at org.apache.accumulo.tserver.FileManager$ScanFileManager.openFileRefs(FileManager.java:466)
	at org.apache.accumulo.tserver.FileManager$ScanFileManager.openFiles(FileManager.java:486)
	at org.apache.accumulo.tserver.Tablet$ScanDataSource.createIterator(Tablet.java:2027)
	at org.apache.accumulo.tserver.Tablet$ScanDataSource.iterator(Tablet.java:1989)
	at org.apache.accumulo.core.iterators.system.SourceSwitchingIterator.seek(SourceSwitchingIterator.java:163)
	at org.apache.accumulo.tserver.Tablet.lookup(Tablet.java:1565)
	at org.apache.accumulo.tserver.Tablet.lookup(Tablet.java:1672)
	at org.apache.accumulo.tserver.TabletServer$ThriftClientHandler$LookupTask.run(TabletServer.java:1114)
	... 6 more
Caused by: java.io.FileNotFoundException: File does not exist: /accumulo/tables/!0/table_info/A000042x.rf
	at org.apache.hadoop.hdfs.DFSClient$DFSInputStream.fetchLocatedBlocks(DFSClient.java:2006)
	at org.apache.hadoop.hdfs.DFSClient$DFSInputStream.openInfo(DFSClient.java:1975)
	at org.apache.hadoop.hdfs.DFSClient$DFSInputStream.<init>(DFSClient.java:1967)
	at org.apache.hadoop.hdfs.DFSClient.open(DFSClient.java:735)
	at org.apache.hadoop.hdfs.DistributedFileSystem.open(DistributedFileSystem.java:165)
	at org.apache.hadoop.fs.FileSystem.open(FileSystem.java:436)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader.getBCFile(CachableBlockFile.java:256)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader.access$000(CachableBlockFile.java:143)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader$MetaBlockLoader.get(CachableBlockFile.java:212)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader.getBlock(CachableBlockFile.java:313)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader.getMetaBlock(CachableBlockFile.java:367)
	at org.apache.accumulo.core.file.blockfile.impl.CachableBlockFile$Reader.getMetaBlock(CachableBlockFile.java:143)
	at org.apache.accumulo.core.file.rfile.RFile$Reader.<init>(RFile.java:825)
	at org.apache.accumulo.core.file.rfile.RFileOperations.openReader(RFileOperations.java:79)
	at org.apache.accumulo.core.file.DispatchingFileFactory.openReader(FileOperations.java:119)
	at org.apache.accumulo.tserver.FileManager.reserveReaders(FileManager.java:314)
	... 16 more

Here's some other pieces of context:

HDFS contents:

ubuntu@ip-10-10-1-115:/data0/logs/accumulo$ hadoop fs -lsr /accumulo/tables/
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 00:32 /accumulo/tables/!0
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 01:06 /accumulo/tables/!0/default_tablet
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 10:49 /accumulo/tables/!0/table_info
-rw-r--r--   5 accumulo hadoop       1698 2013-12-10 00:34 /accumulo/tables/!0/table_info/F0000000.rf
-rw-r--r--   5 accumulo hadoop      43524 2013-12-10 01:53 /accumulo/tables/!0/table_info/F000062q.rf
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 00:32 /accumulo/tables/+r
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 10:45 /accumulo/tables/+r/root_tablet
-rw-r--r--   5 accumulo hadoop       2070 2013-12-10 10:45 /accumulo/tables/+r/root_tablet/A0000738.rf
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 00:33 /accumulo/tables/1
drwxr-xr-x   - accumulo hadoop          0 2013-12-10 00:33 /accumulo/tables/1/default_tablet

ZooKeeper entries

[zk: localhost:2181(CONNECTED) 6] get /accumulo/371cfa3e-fe96-4a50-92e9-da7572589ffa/root_tablet/dir 
hdfs://10.10.1.115:9000/accumulo/tables/+r/root_tablet
cZxid = 0x1b
ctime = Tue Dec 10 00:32:56 EST 2013
mZxid = 0x1b
mtime = Tue Dec 10 00:32:56 EST 2013
pZxid = 0x1b
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 54
numChildren = 0

I'm going to preserve the state of this machine in HDFS for a while but not forever, so if there are other pieces of context people need, let me know.

Issue Links

• is related to: ACCUMULO-2668 slow WAL writes
• relates to: ACCUMULO-1481 Root tablet in its own table