hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "CW Chung (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HDFS-1907) BlockMissingException upon concurrent read and write: reader was doing file position read while writer is doing write without hflush
Date Tue, 10 May 2011 02:00:03 GMT

     [ https://issues.apache.org/jira/browse/HDFS-1907?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

CW Chung updated HDFS-1907:
---------------------------

    Description: 
BlockMissingException is thrown under this test scenario:
Two different processes doing concurrent file r/w: one read and the other write on the same
file
  - writer keep doing file write
  - reader doing position file read from beginning of the file to the visible end of file,
repeatedly

The reader is basically doing:
  byteRead = in.read(currentPosition, buffer, 0, byteToReadThisRound);
where CurrentPostion=0, buffer is a byte array buffer, byteToReadThisRound = 1024*10000;

Usually it does not fail right away. I have to read, close file, re-open the same file a few
times to create the problem. I'll pose a test program to repro this problem after I've cleaned
up a bit my current test program.



  was:
BlockMissingException is thrown under this test scenario:
- two different processes doing concurrent file r/w: one read and the other write on the same
file
- writer keep doing file write
- reader doing position file read from beginning of the file to the visible end of file, repeatedly

The call is basically:
  	byteRead = in.read(currentPosition, buffer, 0, byteToReadThisRound);
where CurrentPostion=0, buffer is a byte array buffer, byteToReadThisRound = 1024*10000;
Usually it does not fail right away. I have to read, close file, re-open the same file a few
times to create the problem. I'll pose a test program to repro this problem after I've cleaned
up a bit my current test program.


Error msg:
=========================
11/05/08 19:05:48 WARN hdfs.DFSClient: Failed to connect to /xxx.xx.xx.xxx:1004 for file /tmp/N/909NF
for block
BP-1632719171-xxx.xx.xx.xxx-1303748685682:blk_-8940328094159486414_3653:java.io.IOException:
Got error for
OP_READ_BLOCK, self=/xxx.xx.xx.xxx:36405, remote=/xxx.xx.xx.xxx:1004, for file /tmp/N/909NF,
for pool
BP-1632719171-xxx.xx.xx.xxx-1303748685682 block -8940328094159486414_3653
    at org.apache.hadoop.hdfs.BlockReader.newBlockReader(BlockReader.java:398)
    at org.apache.hadoop.hdfs.DFSInputStream.fetchBlockByteRange(DFSInputStream.java:631)
    at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:704)
    at org.apache.hadoop.fs.FSDataInputStream.read(FSDataInputStream.java:51)
    at TAppend.readUntilVisibleEnd(TAppend.java:441)
    at TAppend.readUntilEnd(TAppend.java:474)
    at TAppend.testReadOnly(TAppend.java:956)
    at TAppend.main(TAppend.java:1215)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:192)
....
##### Caught Exception in testReadOnly while reading.
java.io.IOException: Exception caught in readUntilVisibleEnd: Reader  currentOffset = 0 ;
totalByteRead =0 ; latest byteRead = 0 ; visibleLen= 67824640 ; byteLeftToRead = 67824640
; bufferLen = 10240000 ; chunkNumber= 0 ; input pos = 0 ; byteToReadThisRound = 10240000 ;
Filename = /tmp/N/909NF, ReadParam - CurrentPostion=0, offset=0, size=10240000


    at TAppend.readUntilVisibleEnd(TAppend.java:457)
    at TAppend.readUntilEnd(TAppend.java:474)
    at TAppend.testReadOnly(TAppend.java:956)
    at TAppend.main(TAppend.java:1215)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:192)

Caused by: org.apache.hadoop.hdfs.BlockMissingException: Could not obtain block:
BP-1632719171-xxx.xx.xx.xxx-1303748685682:blk_-8940328094159486414_3653 file=/tmp/N/909NF
    at org.apache.hadoop.hdfs.DFSInputStream.chooseDataNode(DFSInputStream.java:570)
    at org.apache.hadoop.hdfs.DFSInputStream.fetchBlockByteRange(DFSInputStream.java:618)
    at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:704)
    at org.apache.hadoop.fs.FSDataInputStream.read(FSDataInputStream.java:51)
    at TAppend.readUntilVisibleEnd(TAppend.java:441)
    ... 8 more



> BlockMissingException upon concurrent read and write: reader was doing file position
read while writer is doing write without hflush
> ------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-1907
>                 URL: https://issues.apache.org/jira/browse/HDFS-1907
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: hdfs client
>    Affects Versions: 0.23.0
>         Environment: Run on a real cluster. Using the latest 0.23 build.
>            Reporter: CW Chung
>
> BlockMissingException is thrown under this test scenario:
> Two different processes doing concurrent file r/w: one read and the other write on the
same file
>   - writer keep doing file write
>   - reader doing position file read from beginning of the file to the visible end of
file, repeatedly
> The reader is basically doing:
>   byteRead = in.read(currentPosition, buffer, 0, byteToReadThisRound);
> where CurrentPostion=0, buffer is a byte array buffer, byteToReadThisRound = 1024*10000;
> Usually it does not fail right away. I have to read, close file, re-open the same file
a few times to create the problem. I'll pose a test program to repro this problem after I've
cleaned up a bit my current test program.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message