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Posted to common-user@hadoop.apache.org by Rob Collins <Ro...@clickforensics.com> on 2008/06/12 23:04:17 UTC
What did I do wrong? (Too many fetch-failures)
In a previous life, I had no problems setting up a small cluster. Now I have managed to mess it up. I see reports of similar symptoms in this mailing list, but I cannot see any solutions to the problem. I am working with 0.16.4.
Any suggestions you can provide would be appreciated.
Thanks,
Rob
Here is what I am seeing.
[root@NO01 ~]# sudo -u hadoop /hadoop/hadoop/bin/hadoop jar /hadoop/hadoop/hadoop-*-examples.jar grep input output 'dfs[a-z.]+'
08/06/12 14:50:35 INFO mapred.FileInputFormat: Total input paths to process : 1
08/06/12 14:50:35 INFO mapred.JobClient: Running job: job_200806121449_0001
08/06/12 14:50:36 INFO mapred.JobClient: map 0% reduce 0%
08/06/12 14:50:39 INFO mapred.JobClient: map 54% reduce 0%
08/06/12 14:50:40 INFO mapred.JobClient: map 72% reduce 0%
08/06/12 14:50:41 INFO mapred.JobClient: map 100% reduce 0%
08/06/12 14:50:51 INFO mapred.JobClient: map 100% reduce 2%
08/06/12 14:53:20 INFO mapred.JobClient: map 100% reduce 3%
08/06/12 14:55:50 INFO mapred.JobClient: map 100% reduce 4%
08/06/12 14:58:14 INFO mapred.JobClient: map 100% reduce 5%
08/06/12 14:58:20 INFO mapred.JobClient: map 100% reduce 6%
08/06/12 15:05:54 INFO mapred.JobClient: map 100% reduce 7%
08/06/12 15:05:56 INFO mapred.JobClient: map 100% reduce 10%
08/06/12 15:13:26 INFO mapred.JobClient: map 100% reduce 11%
08/06/12 15:23:36 INFO mapred.JobClient: map 90% reduce 11%
08/06/12 15:23:36 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000005_0, Status : FAILED
Too many fetch-failures
08/06/12 15:23:36 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:23:36 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:23:38 INFO mapred.JobClient: map 100% reduce 11%
08/06/12 15:31:07 INFO mapred.JobClient: map 90% reduce 11%
08/06/12 15:31:07 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000008_0, Status : FAILED
Too many fetch-failures
08/06/12 15:31:07 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:31:07 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:31:08 INFO mapred.JobClient: map 100% reduce 11%
08/06/12 15:33:37 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000001_0, Status : FAILED
Too many fetch-failures
08/06/12 15:33:37 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:33:37 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:36:12 INFO mapred.JobClient: map 100% reduce 12%
08/06/12 15:38:38 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000002_0, Status : FAILED
Too many fetch-failures
08/06/12 15:38:38 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:38:38 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:38:40 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000004_0, Status : FAILED
Too many fetch-failures
08/06/12 15:38:40 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:38:40 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:38:43 INFO mapred.JobClient: map 100% reduce 13%
08/06/12 15:41:14 INFO mapred.JobClient: map 90% reduce 13%
08/06/12 15:41:14 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000010_0, Status : FAILED
Too many fetch-failures
08/06/12 15:41:14 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:41:14 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:41:15 INFO mapred.JobClient: map 100% reduce 13%
08/06/12 15:43:43 INFO mapred.JobClient: map 100% reduce 15%
08/06/12 15:46:13 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000006_0, Status : FAILED
Too many fetch-failures
08/06/12 15:46:13 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:46:13 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:48:49 INFO mapred.JobClient: Task Id : task_200806121449_0001_m_000009_0, Status : FAILED
Too many fetch-failures
08/06/12 15:48:49 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:48:49 WARN mapred.JobClient: Error reading task outputConnection refused
08/06/12 15:53:46 INFO mapred.JobClient: map 100% reduce 16%
08/06/12 15:56:20 INFO mapred.JobClient: map 100% reduce 17%
2008-06-12 15:55:19,975 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:25,981 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:28,983 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:34,989 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:40,995 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:43,997 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:50,003 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:56,007 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:55:59,010 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:56:05,016 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:56:11,021 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:56:14,024 INFO org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) >
2008-06-12 15:56:15,789 WARN org.apache.hadoop.mapred.TaskTracker: getMapOutput(task_200806121449_0001_m_000006_1,2) failed :
org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find task_200806121449_0001_m_000006_1/file.out.index in any of the configured local directories
at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathToRead(LocalDirAllocator.java:359)
at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathToRead(LocalDirAllocator.java:138)
at org.apache.hadoop.mapred.TaskTracker$MapOutputServlet.doGet(TaskTracker.java:2253)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:427)
at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHandler.java:475)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1565)
at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContext.java:635)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1517)
at org.mortbay.http.HttpServer.service(HttpServer.java:954)
at org.mortbay.http.HttpConnection.service(HttpConnection.java:814)
at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:981)
at org.mortbay.http.HttpConnection.handle(HttpConnection.java:831)
at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:244)
at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:357)
at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:534)
[root@NO01 ~]# cat /hadoop/hadoop/conf/hadoop-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>/hadoop/hadoop/tmp/hadoop-${user.name}</value>
<description>A base for other temporary directories.</description>
</property>
<property>
<name>dfs.data.dir</name>
<value>/mnt/dsk1/dfs,/mnt/dsk2/dfs,/mnt/dsk3/dfs,/mnt/dsk4/dfs</value>
<description>Determines where on the local filesystem an DFS data node
should store its blocks. If this is a comma-delimited
list of directories, then data will be stored in all named
directories, typically on different devices.
Directories that do not exist are ignored.
</description>
</property>
<property>
<name>dfs.block.size</name>
<value>67108864</value>
<description>The default block size for new files.</description>
</property>
<property>
<name>fs.default.name</name>
<value>192.168.1.94:54310</value>
</property>
<property>
<name>mapred.job.tracker</name>
<value>192.168.1.94:54311</value>
<description>The host and port that the MapReduce job tracker runs
at. If "local", then jobs are run in-process as a single map
and reduce task.
</description>
</property>
<property>
<name>mapred.local.dir</name>
<!--value>/mnt/dsk1/local,/mnt/dsk2/local,/mnt/dsk3/local,/mnt/dsk4/local,/tmp</value-->
<value>/tmp</value>
<description>The local directory where MapReduce stores intermediate
data files. May be a comma-separated list of
directories on different devices in order to spread disk i/o.
Directories that do not exist are ignored.
</description>
</property>
<property>
<name>mapred.map.tasks</name>
<value>11</value>
<description>The default number of map tasks per job. Typically set
to a prime several times greater than number of available hosts.
Ignored when mapred.job.tracker is "local".
</description>
</property>
<property>
<name>mapred.reduce.tasks</name>
<value>3</value>
<description>The default number of reduce tasks per job. Typically set
to a prime close to the number of available hosts. Ignored when
mapred.job.tracker is "local".
</description>
</property>
<property>
<name>mapred.tasktracker.map.tasks.maximum</name>
<value>8</value>
<description>The maximum number of map tasks that will be run
simultaneously by a task tracker.
</description>
</property>
<property>
<name>mapred.tasktracker.reduce.tasks.maximum</name>
<value>8</value>
<description>The maximum number of reduce tasks that will be run
simultaneously by a task tracker.
</description>
</property>
<property>
<name>mapred.child.java.opts</name>
<value>-Xmx1800m</value>
<description>Java opts for the task tracker child processes.
The following symbol, if present, will be interpolated: @taskid@ is replaced
by current TaskID. Any other occurrences of '@' will go unchanged.
For example, to enable verbose gc logging to a file named for the taskid in
/tmp and to set the heap maximum to be a gigabyte, pass a 'value' of:
-Xmx1024m -verbose:gc -Xloggc:/tmp/@taskid@.gc
</description>
</property>
<property>
<name>mapred.speculative.execution</name>
<value>false</value>
<description>If true, then multiple instances of some map and reduce tasks
may be executed in parallel.
</description>
</property>
</configuration>
Re: What did I do wrong? (Too many fetch-failures)
Posted by Andreas Kostyrka <an...@kostyrka.org>.
For me, I had to upgrade to 0.17.0, which made this problem go away magically.
No idea if that will solve your problem.
Andreas
On Thursday 12 June 2008 23:04:17 Rob Collins wrote:
> In a previous life, I had no problems setting up a small cluster. Now I
> have managed to mess it up. I see reports of similar symptoms in this
> mailing list, but I cannot see any solutions to the problem. I am working
> with 0.16.4.
>
> Any suggestions you can provide would be appreciated.
>
> Thanks,
> Rob
>
> Here is what I am seeing.
>
> [root@NO01 ~]# sudo -u hadoop /hadoop/hadoop/bin/hadoop jar
> /hadoop/hadoop/hadoop-*-examples.jar grep input output 'dfs[a-z.]+'
> 08/06/12 14:50:35 INFO mapred.FileInputFormat: Total input paths to process
> : 1 08/06/12 14:50:35 INFO mapred.JobClient: Running job:
> job_200806121449_0001 08/06/12 14:50:36 INFO mapred.JobClient: map 0%
> reduce 0%
> 08/06/12 14:50:39 INFO mapred.JobClient: map 54% reduce 0%
> 08/06/12 14:50:40 INFO mapred.JobClient: map 72% reduce 0%
> 08/06/12 14:50:41 INFO mapred.JobClient: map 100% reduce 0%
> 08/06/12 14:50:51 INFO mapred.JobClient: map 100% reduce 2%
> 08/06/12 14:53:20 INFO mapred.JobClient: map 100% reduce 3%
> 08/06/12 14:55:50 INFO mapred.JobClient: map 100% reduce 4%
> 08/06/12 14:58:14 INFO mapred.JobClient: map 100% reduce 5%
> 08/06/12 14:58:20 INFO mapred.JobClient: map 100% reduce 6%
> 08/06/12 15:05:54 INFO mapred.JobClient: map 100% reduce 7%
> 08/06/12 15:05:56 INFO mapred.JobClient: map 100% reduce 10%
> 08/06/12 15:13:26 INFO mapred.JobClient: map 100% reduce 11%
> 08/06/12 15:23:36 INFO mapred.JobClient: map 90% reduce 11%
> 08/06/12 15:23:36 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000005_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:23:36 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:23:36 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:23:38 INFO
> mapred.JobClient: map 100% reduce 11%
> 08/06/12 15:31:07 INFO mapred.JobClient: map 90% reduce 11%
> 08/06/12 15:31:07 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000008_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:31:07 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:31:07 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:31:08 INFO
> mapred.JobClient: map 100% reduce 11%
> 08/06/12 15:33:37 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000001_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:33:37 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:33:37 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:36:12 INFO
> mapred.JobClient: map 100% reduce 12%
> 08/06/12 15:38:38 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000002_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:38:38 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:38:38 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:38:40 INFO
> mapred.JobClient: Task Id : task_200806121449_0001_m_000004_0, Status :
> FAILED Too many fetch-failures
> 08/06/12 15:38:40 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:38:40 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:38:43 INFO
> mapred.JobClient: map 100% reduce 13%
> 08/06/12 15:41:14 INFO mapred.JobClient: map 90% reduce 13%
> 08/06/12 15:41:14 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000010_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:41:14 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:41:14 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:41:15 INFO
> mapred.JobClient: map 100% reduce 13%
> 08/06/12 15:43:43 INFO mapred.JobClient: map 100% reduce 15%
> 08/06/12 15:46:13 INFO mapred.JobClient: Task Id :
> task_200806121449_0001_m_000006_0, Status : FAILED Too many fetch-failures
> 08/06/12 15:46:13 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:46:13 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:48:49 INFO
> mapred.JobClient: Task Id : task_200806121449_0001_m_000009_0, Status :
> FAILED Too many fetch-failures
> 08/06/12 15:48:49 WARN mapred.JobClient: Error reading task
> outputConnection refused 08/06/12 15:48:49 WARN mapred.JobClient: Error
> reading task outputConnection refused 08/06/12 15:53:46 INFO
> mapred.JobClient: map 100% reduce 16%
> 08/06/12 15:56:20 INFO mapred.JobClient: map 100% reduce 17%
>
> 2008-06-12 15:55:19,975 INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:55:25,981 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:55:28,983
> INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:55:34,989 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:55:40,995
> INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:55:43,997 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:55:50,003
> INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:55:56,007 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:55:59,010
> INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:56:05,016 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:56:11,021
> INFO org.apache.hadoop.mapred.TaskTracker:
> task_200806121449_0001_r_000002_0 0.21212122% reduce > copy (7 of 11 at
> 0.00 MB/s) > 2008-06-12 15:56:14,024 INFO
> org.apache.hadoop.mapred.TaskTracker: task_200806121449_0001_r_000002_0
> 0.21212122% reduce > copy (7 of 11 at 0.00 MB/s) > 2008-06-12 15:56:15,789
> WARN org.apache.hadoop.mapred.TaskTracker:
> getMapOutput(task_200806121449_0001_m_000006_1,2) failed :
> org.apache.hadoop.util.DiskChecker$DiskErrorException: Could not find
> task_200806121449_0001_m_000006_1/file.out.index in any of the configured
> local directories at
> org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathToRe
>ad(LocalDirAllocator.java:359) at
> org.apache.hadoop.fs.LocalDirAllocator.getLocalPathToRead(LocalDirAllocator
>.java:138) at
> org.apache.hadoop.mapred.TaskTracker$MapOutputServlet.doGet(TaskTracker.jav
>a:2253) at javax.servlet.http.HttpServlet.service(HttpServlet.java:689) at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:802) at
> org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:427) at
> org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHand
>ler.java:475) at
> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567) at
> org.mortbay.http.HttpContext.handle(HttpContext.java:1565) at
> org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContex
>t.java:635) at org.mortbay.http.HttpContext.handle(HttpContext.java:1517) at
> org.mortbay.http.HttpServer.service(HttpServer.java:954) at
> org.mortbay.http.HttpConnection.service(HttpConnection.java:814) at
> org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:981) at
> org.mortbay.http.HttpConnection.handle(HttpConnection.java:831) at
> org.mortbay.http.SocketListener.handleConnection(SocketListener.java:244)
> at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:357) at
> org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:534)
>
> [root@NO01 ~]# cat /hadoop/hadoop/conf/hadoop-site.xml
> <?xml version="1.0"?>
> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
>
> <!-- Put site-specific property overrides in this file. -->
>
> <configuration>
>
> <property>
> <name>hadoop.tmp.dir</name>
> <value>/hadoop/hadoop/tmp/hadoop-${user.name}</value>
> <description>A base for other temporary directories.</description>
> </property>
>
> <property>
> <name>dfs.data.dir</name>
> <value>/mnt/dsk1/dfs,/mnt/dsk2/dfs,/mnt/dsk3/dfs,/mnt/dsk4/dfs</value>
> <description>Determines where on the local filesystem an DFS data node
> should store its blocks. If this is a comma-delimited
> list of directories, then data will be stored in all named
> directories, typically on different devices.
> Directories that do not exist are ignored.
> </description>
> </property>
>
> <property>
> <name>dfs.block.size</name>
> <value>67108864</value>
> <description>The default block size for new files.</description>
> </property>
>
> <property>
> <name>fs.default.name</name>
> <value>192.168.1.94:54310</value>
> </property>
>
>
> <property>
> <name>mapred.job.tracker</name>
> <value>192.168.1.94:54311</value>
> <description>The host and port that the MapReduce job tracker runs
> at. If "local", then jobs are run in-process as a single map
> and reduce task.
> </description>
> </property>
>
> <property>
> <name>mapred.local.dir</name>
>
> <!--value>/mnt/dsk1/local,/mnt/dsk2/local,/mnt/dsk3/local,/mnt/dsk4/local,/
>tmp</value--> <value>/tmp</value>
> <description>The local directory where MapReduce stores intermediate
> data files. May be a comma-separated list of
> directories on different devices in order to spread disk i/o.
> Directories that do not exist are ignored.
> </description>
> </property>
>
> <property>
> <name>mapred.map.tasks</name>
> <value>11</value>
> <description>The default number of map tasks per job. Typically set
> to a prime several times greater than number of available hosts.
> Ignored when mapred.job.tracker is "local".
> </description>
> </property>
>
> <property>
> <name>mapred.reduce.tasks</name>
> <value>3</value>
> <description>The default number of reduce tasks per job. Typically set
> to a prime close to the number of available hosts. Ignored when
> mapred.job.tracker is "local".
> </description>
> </property>
>
> <property>
> <name>mapred.tasktracker.map.tasks.maximum</name>
> <value>8</value>
> <description>The maximum number of map tasks that will be run
> simultaneously by a task tracker.
> </description>
> </property>
>
> <property>
> <name>mapred.tasktracker.reduce.tasks.maximum</name>
> <value>8</value>
> <description>The maximum number of reduce tasks that will be run
> simultaneously by a task tracker.
> </description>
> </property>
>
> <property>
> <name>mapred.child.java.opts</name>
> <value>-Xmx1800m</value>
> <description>Java opts for the task tracker child processes.
> The following symbol, if present, will be interpolated: @taskid@ is
> replaced by current TaskID. Any other occurrences of '@' will go unchanged.
> For example, to enable verbose gc logging to a file named for the taskid in
> /tmp and to set the heap maximum to be a gigabyte, pass a 'value' of:
> -Xmx1024m -verbose:gc -Xloggc:/tmp/@taskid@.gc
> </description>
>
> </property>
>
> <property>
> <name>mapred.speculative.execution</name>
> <value>false</value>
> <description>If true, then multiple instances of some map and reduce
> tasks may be executed in parallel.
> </description>
> </property>
>
>
> </configuration>