Reduce hangs
|
View:
New views
12 Messages
—
Rating Filter:
Alert me
|
 |
Reduce hangs
by Yunhong Gu1
::
Rate this Message:
Hi, If someone knows how to fix the problem described below, please help me out. Thanks! I am testing Hadoop on 2-node cluster and the "reduce" always hangs at some stage, even if I use different clusters. My OS is Debian Linux kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version is 1.5.0_01-b08. I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and when the map stage finishes, the reduce stage will hang somewhere in the middle, sometimes at 0%. I also tried any other mapreduce program I can find in the example jar package but they all hang. The log file simply print 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: task_200801181424_0004_r_000000_0 0.0% reduce > copy > 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: task_200801181424_0004_r_000000_0 0.0% reduce > copy > 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: task_200801181424_0004_r_000000_0 0.0% reduce > copy > forever. The program does work if I start Hadoop only on single node. Below is my hadoop-site.xml configuration: <configuration> <property> <name>fs.default.name</name> <value>10.0.0.1:60000</value> </property> <property> <name>mapred.job.tracker</name> <value>10.0.0.1:60001</value> </property> <property> <name>dfs.data.dir</name> <value>/raid/hadoop/data</value> </property> <property> <name>mapred.local.dir</name> <value>/raid/hadoop/mapred</value> </property> <property> <name>hadoop.tmp.dir</name> <value>/raid/hadoop/tmp</value> </property> <property> <name>mapred.child.java.opts</name> <value>-Xmx1024m</value> </property> <property> <name>mapred.tasktracker.tasks.maximum</name> <value>4</value> </property> <!-- <property> <name>mapred.map.tasks</name> <value>7</value> </property> <property> <name>mapred.reduce.tasks</name> <value>3</value> </property> --> <property> <name>fs.inmemory.size.mb</name> <value>200</value> </property> <property> <name>dfs.block.size</name> <value>134217728</value> </property> <property> <name>io.sort.factor</name> <value>100</value> </property> <property> <name>io.sort.mb</name> <value>200</value> </property> <property> <name>io.file.buffer.size</name> <value>131072</value> </property> </configuration> |
|
|
Re: Reduce hangs
by Miles Osborne
::
Rate this Message:
I had the same problem. If I recall, the fix is to add the following to
your hadoop-site.xml file: <property> <name>mapred.reduce.copy.backoff</name> <value>5</value> </property> See hadoop-1984 Miles On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: > > > Hi, > > If someone knows how to fix the problem described below, please help me > out. Thanks! > > I am testing Hadoop on 2-node cluster and the "reduce" always hangs at > some stage, even if I use different clusters. My OS is Debian Linux kernel > 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version is > 1.5.0_01-b08. > > I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and when > the map stage finishes, the reduce stage will hang somewhere in the > middle, sometimes at 0%. I also tried any other mapreduce program I can > find in the example jar package but they all hang. > > The log file simply print > 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > > forever. > > The program does work if I start Hadoop only on single node. > > Below is my hadoop-site.xml configuration: > > <configuration> > > <property> > <name>fs.default.name</name> > <value>10.0.0.1:60000</value> > </property> > > <property> > <name>mapred.job.tracker</name> > <value>10.0.0.1:60001</value> > </property> > > <property> > <name>dfs.data.dir</name> > <value>/raid/hadoop/data</value> > </property> > > <property> > <name>mapred.local.dir</name> > <value>/raid/hadoop/mapred</value> > </property> > > <property> > <name>hadoop.tmp.dir</name> > <value>/raid/hadoop/tmp</value> > </property> > > <property> > <name>mapred.child.java.opts</name> > <value>-Xmx1024m</value> > </property> > > <property> > <name>mapred.tasktracker.tasks.maximum</name> > <value>4</value> > </property> > > <!-- > <property> > <name>mapred.map.tasks</name> > <value>7</value> > </property> > > <property> > <name>mapred.reduce.tasks</name> > <value>3</value> > </property> > --> > > <property> > <name>fs.inmemory.size.mb</name> > <value>200</value> > </property> > > <property> > <name>dfs.block.size</name> > <value>134217728</value> > </property> > > <property> > <name>io.sort.factor</name> > <value>100</value> > </property> > > <property> > <name>io.sort.mb</name> > <value>200</value> > </property> > > <property> > <name>io.file.buffer.size</name> > <value>131072</value> > </property> > > </configuration> > > |
|
|
Re: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
Hi, Miles, Thanks for your information. I applied this but the problem still exists. By the way, when this happens, the CPUs are idle and doing nothing. Yunhong On Fri, 18 Jan 2008, Miles Osborne wrote: > I had the same problem. If I recall, the fix is to add the following to > your hadoop-site.xml file: > > <property> > <name>mapred.reduce.copy.backoff</name> > <value>5</value> > </property> > > See hadoop-1984 > > Miles > > > On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: >> >> >> Hi, >> >> If someone knows how to fix the problem described below, please help me >> out. Thanks! >> >> I am testing Hadoop on 2-node cluster and the "reduce" always hangs at >> some stage, even if I use different clusters. My OS is Debian Linux kernel >> 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version is >> 1.5.0_01-b08. >> >> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and when >> the map stage finishes, the reduce stage will hang somewhere in the >> middle, sometimes at 0%. I also tried any other mapreduce program I can >> find in the example jar package but they all hang. >> >> The log file simply print >> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> >> forever. >> >> The program does work if I start Hadoop only on single node. >> >> Below is my hadoop-site.xml configuration: >> >> <configuration> >> >> <property> >> <name>fs.default.name</name> >> <value>10.0.0.1:60000</value> >> </property> >> >> <property> >> <name>mapred.job.tracker</name> >> <value>10.0.0.1:60001</value> >> </property> >> >> <property> >> <name>dfs.data.dir</name> >> <value>/raid/hadoop/data</value> >> </property> >> >> <property> >> <name>mapred.local.dir</name> >> <value>/raid/hadoop/mapred</value> >> </property> >> >> <property> >> <name>hadoop.tmp.dir</name> >> <value>/raid/hadoop/tmp</value> >> </property> >> >> <property> >> <name>mapred.child.java.opts</name> >> <value>-Xmx1024m</value> >> </property> >> >> <property> >> <name>mapred.tasktracker.tasks.maximum</name> >> <value>4</value> >> </property> >> >> <!-- >> <property> >> <name>mapred.map.tasks</name> >> <value>7</value> >> </property> >> >> <property> >> <name>mapred.reduce.tasks</name> >> <value>3</value> >> </property> >> --> >> >> <property> >> <name>fs.inmemory.size.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>dfs.block.size</name> >> <value>134217728</value> >> </property> >> >> <property> >> <name>io.sort.factor</name> >> <value>100</value> >> </property> >> >> <property> >> <name>io.sort.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>io.file.buffer.size</name> >> <value>131072</value> >> </property> >> >> </configuration> >> >> > |
|
|
Re: Reduce hangs
by Miles Osborne
::
Rate this Message:
I think it takes a while to actually work, so be patient!
Miles On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: > > > Hi, Miles, > > Thanks for your information. I applied this but the problem still exists. > By the way, when this happens, the CPUs are idle and doing nothing. > > Yunhong > > On Fri, 18 Jan 2008, Miles Osborne wrote: > > > I had the same problem. If I recall, the fix is to add the following to > > your hadoop-site.xml file: > > > > <property> > > <name>mapred.reduce.copy.backoff</name> > > <value>5</value> > > </property> > > > > See hadoop-1984 > > > > Miles > > > > > > On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: > >> > >> > >> Hi, > >> > >> If someone knows how to fix the problem described below, please help me > >> out. Thanks! > >> > >> I am testing Hadoop on 2-node cluster and the "reduce" always hangs at > >> some stage, even if I use different clusters. My OS is Debian Linux > kernel > >> 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version > is > >> 1.5.0_01-b08. > >> > >> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and > when > >> the map stage finishes, the reduce stage will hang somewhere in the > >> middle, sometimes at 0%. I also tried any other mapreduce program I can > >> find in the example jar package but they all hang. > >> > >> The log file simply print > >> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> > >> forever. > >> > >> The program does work if I start Hadoop only on single node. > >> > >> Below is my hadoop-site.xml configuration: > >> > >> <configuration> > >> > >> <property> > >> <name>fs.default.name</name> > >> <value>10.0.0.1:60000</value> > >> </property> > >> > >> <property> > >> <name>mapred.job.tracker</name> > >> <value>10.0.0.1:60001</value> > >> </property> > >> > >> <property> > >> <name>dfs.data.dir</name> > >> <value>/raid/hadoop/data</value> > >> </property> > >> > >> <property> > >> <name>mapred.local.dir</name> > >> <value>/raid/hadoop/mapred</value> > >> </property> > >> > >> <property> > >> <name>hadoop.tmp.dir</name> > >> <value>/raid/hadoop/tmp</value> > >> </property> > >> > >> <property> > >> <name>mapred.child.java.opts</name> > >> <value>-Xmx1024m</value> > >> </property> > >> > >> <property> > >> <name>mapred.tasktracker.tasks.maximum</name> > >> <value>4</value> > >> </property> > >> > >> <!-- > >> <property> > >> <name>mapred.map.tasks</name> > >> <value>7</value> > >> </property> > >> > >> <property> > >> <name>mapred.reduce.tasks</name> > >> <value>3</value> > >> </property> > >> --> > >> > >> <property> > >> <name>fs.inmemory.size.mb</name> > >> <value>200</value> > >> </property> > >> > >> <property> > >> <name>dfs.block.size</name> > >> <value>134217728</value> > >> </property> > >> > >> <property> > >> <name>io.sort.factor</name> > >> <value>100</value> > >> </property> > >> > >> <property> > >> <name>io.sort.mb</name> > >> <value>200</value> > >> </property> > >> > >> <property> > >> <name>io.file.buffer.size</name> > >> <value>131072</value> > >> </property> > >> > >> </configuration> > >> > >> > > > |
|
|
Re: Reduce hangs
by Jason Venner-2
::
Rate this Message:
When this was happening to us, there was a block replication error and
one node was in an endless loop trying to replicate a block to another node which would not accept it. In our case most of the cluster was idle but a cpu on the machine trying send the block was heavily used. We never were able to isolate the cause, and it stopped happening for us when we upgraded to 0.15.1 --- Attributor is hiring Hadoop Wranglers, contact if interested. Yunhong Gu1 wrote: > > Hi, > > If someone knows how to fix the problem described below, please help > me out. Thanks! > > I am testing Hadoop on 2-node cluster and the "reduce" always hangs at > some stage, even if I use different clusters. My OS is Debian Linux > kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java > version is 1.5.0_01-b08. > > I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and > when the map stage finishes, the reduce stage will hang somewhere in > the middle, sometimes at 0%. I also tried any other mapreduce program > I can find in the example jar package but they all hang. > > The log file simply print > 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > > forever. > > The program does work if I start Hadoop only on single node. > > Below is my hadoop-site.xml configuration: > > <configuration> > > <property> > <name>fs.default.name</name> > <value>10.0.0.1:60000</value> > </property> > > <property> > <name>mapred.job.tracker</name> > <value>10.0.0.1:60001</value> > </property> > > <property> > <name>dfs.data.dir</name> > <value>/raid/hadoop/data</value> > </property> > > <property> > <name>mapred.local.dir</name> > <value>/raid/hadoop/mapred</value> > </property> > > <property> > <name>hadoop.tmp.dir</name> > <value>/raid/hadoop/tmp</value> > </property> > > <property> > <name>mapred.child.java.opts</name> > <value>-Xmx1024m</value> > </property> > > <property> > <name>mapred.tasktracker.tasks.maximum</name> > <value>4</value> > </property> > > <!-- > <property> > <name>mapred.map.tasks</name> > <value>7</value> > </property> > > <property> > <name>mapred.reduce.tasks</name> > <value>3</value> > </property> > --> > > <property> > <name>fs.inmemory.size.mb</name> > <value>200</value> > </property> > > <property> > <name>dfs.block.size</name> > <value>134217728</value> > </property> > > <property> > <name>io.sort.factor</name> > <value>100</value> > </property> > > <property> > <name>io.sort.mb</name> > <value>200</value> > </property> > > <property> > <name>io.file.buffer.size</name> > <value>131072</value> > </property> > > </configuration> > |
|
|
Re: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
I am using 0.15.2, and in my case, CPUs on both nodes are idle. It looks like the program is trapped into a synchronization deadlock or some waiting state that will never be awaken. Yunhong On Fri, 18 Jan 2008, Jason Venner wrote: > When this was happening to us, there was a block replication error and one > node was in an endless loop trying to replicate a block to another node which > would not accept it. In our case most of the cluster was idle but a cpu on > the machine trying send the block was heavily used. > > We never were able to isolate the cause, and it stopped happening for us when > we upgraded to 0.15.1 > > --- > Attributor is hiring Hadoop Wranglers, contact if interested. > > Yunhong Gu1 wrote: >> >> Hi, >> >> If someone knows how to fix the problem described below, please help me >> out. Thanks! >> >> I am testing Hadoop on 2-node cluster and the "reduce" always hangs at some >> stage, even if I use different clusters. My OS is Debian Linux kernel 2.6 >> (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version is >> 1.5.0_01-b08. >> >> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and when >> the map stage finishes, the reduce stage will hang somewhere in the middle, >> sometimes at 0%. I also tried any other mapreduce program I can find in the >> example jar package but they all hang. >> >> The log file simply print >> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> >> forever. >> >> The program does work if I start Hadoop only on single node. >> >> Below is my hadoop-site.xml configuration: >> >> <configuration> >> >> <property> >> <name>fs.default.name</name> >> <value>10.0.0.1:60000</value> >> </property> >> >> <property> >> <name>mapred.job.tracker</name> >> <value>10.0.0.1:60001</value> >> </property> >> >> <property> >> <name>dfs.data.dir</name> >> <value>/raid/hadoop/data</value> >> </property> >> >> <property> >> <name>mapred.local.dir</name> >> <value>/raid/hadoop/mapred</value> >> </property> >> >> <property> >> <name>hadoop.tmp.dir</name> >> <value>/raid/hadoop/tmp</value> >> </property> >> >> <property> >> <name>mapred.child.java.opts</name> >> <value>-Xmx1024m</value> >> </property> >> >> <property> >> <name>mapred.tasktracker.tasks.maximum</name> >> <value>4</value> >> </property> >> >> <!-- >> <property> >> <name>mapred.map.tasks</name> >> <value>7</value> >> </property> >> >> <property> >> <name>mapred.reduce.tasks</name> >> <value>3</value> >> </property> >> --> >> >> <property> >> <name>fs.inmemory.size.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>dfs.block.size</name> >> <value>134217728</value> >> </property> >> >> <property> >> <name>io.sort.factor</name> >> <value>100</value> >> </property> >> >> <property> >> <name>io.sort.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>io.file.buffer.size</name> >> <value>131072</value> >> </property> >> >> </configuration> >> > |
|
|
Re: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
The program "mrbench" takes 1 second on a single node, so I think waiting for 1 minute should be long enough. And I also restarted Hadoop after I updated the config file. Yunhong On Fri, 18 Jan 2008, Miles Osborne wrote: > I think it takes a while to actually work, so be patient! > > Miles > > On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: >> >> >> Hi, Miles, >> >> Thanks for your information. I applied this but the problem still exists. >> By the way, when this happens, the CPUs are idle and doing nothing. >> >> Yunhong >> >> On Fri, 18 Jan 2008, Miles Osborne wrote: >> >>> I had the same problem. If I recall, the fix is to add the following to >>> your hadoop-site.xml file: >>> >>> <property> >>> <name>mapred.reduce.copy.backoff</name> >>> <value>5</value> >>> </property> >>> >>> See hadoop-1984 >>> >>> Miles >>> >>> >>> On 18/01/2008, Yunhong Gu1 <ygu1@...> wrote: >>>> >>>> >>>> Hi, >>>> >>>> If someone knows how to fix the problem described below, please help me >>>> out. Thanks! >>>> >>>> I am testing Hadoop on 2-node cluster and the "reduce" always hangs at >>>> some stage, even if I use different clusters. My OS is Debian Linux >> kernel >>>> 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version >> is >>>> 1.5.0_01-b08. >>>> >>>> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and >> when >>>> the map stage finishes, the reduce stage will hang somewhere in the >>>> middle, sometimes at 0%. I also tried any other mapreduce program I can >>>> find in the example jar package but they all hang. >>>> >>>> The log file simply print >>>> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> >>>> forever. >>>> >>>> The program does work if I start Hadoop only on single node. >>>> >>>> Below is my hadoop-site.xml configuration: >>>> >>>> <configuration> >>>> >>>> <property> >>>> <name>fs.default.name</name> >>>> <value>10.0.0.1:60000</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.job.tracker</name> >>>> <value>10.0.0.1:60001</value> >>>> </property> >>>> >>>> <property> >>>> <name>dfs.data.dir</name> >>>> <value>/raid/hadoop/data</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.local.dir</name> >>>> <value>/raid/hadoop/mapred</value> >>>> </property> >>>> >>>> <property> >>>> <name>hadoop.tmp.dir</name> >>>> <value>/raid/hadoop/tmp</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.child.java.opts</name> >>>> <value>-Xmx1024m</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.tasktracker.tasks.maximum</name> >>>> <value>4</value> >>>> </property> >>>> >>>> <!-- >>>> <property> >>>> <name>mapred.map.tasks</name> >>>> <value>7</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.reduce.tasks</name> >>>> <value>3</value> >>>> </property> >>>> --> >>>> >>>> <property> >>>> <name>fs.inmemory.size.mb</name> >>>> <value>200</value> >>>> </property> >>>> >>>> <property> >>>> <name>dfs.block.size</name> >>>> <value>134217728</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.sort.factor</name> >>>> <value>100</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.sort.mb</name> >>>> <value>200</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.file.buffer.size</name> >>>> <value>131072</value> >>>> </property> >>>> >>>> </configuration> >>>> >>>> >>> >> > |
|
|
Re: Reduce hangs
by Konstantin Shvachko
::
Rate this Message:
Looks like we still have this unsolved mysterious problem:
http://issues.apache.org/jira/browse/HADOOP-1374 Could it be related to HADOOP-1246? Arun? Thanks, --Konstantin Yunhong Gu1 wrote: > > Hi, > > If someone knows how to fix the problem described below, please help me > out. Thanks! > > I am testing Hadoop on 2-node cluster and the "reduce" always hangs at > some stage, even if I use different clusters. My OS is Debian Linux > kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java > version is 1.5.0_01-b08. > > I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and > when the map stage finishes, the reduce stage will hang somewhere in the > middle, sometimes at 0%. I also tried any other mapreduce program I can > find in the example jar package but they all hang. > > The log file simply print > 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: > task_200801181424_0004_r_000000_0 0.0% reduce > copy > > > forever. > > The program does work if I start Hadoop only on single node. > > Below is my hadoop-site.xml configuration: > > <configuration> > > <property> > <name>fs.default.name</name> > <value>10.0.0.1:60000</value> > </property> > > <property> > <name>mapred.job.tracker</name> > <value>10.0.0.1:60001</value> > </property> > > <property> > <name>dfs.data.dir</name> > <value>/raid/hadoop/data</value> > </property> > > <property> > <name>mapred.local.dir</name> > <value>/raid/hadoop/mapred</value> > </property> > > <property> > <name>hadoop.tmp.dir</name> > <value>/raid/hadoop/tmp</value> > </property> > > <property> > <name>mapred.child.java.opts</name> > <value>-Xmx1024m</value> > </property> > > <property> > <name>mapred.tasktracker.tasks.maximum</name> > <value>4</value> > </property> > > <!-- > <property> > <name>mapred.map.tasks</name> > <value>7</value> > </property> > > <property> > <name>mapred.reduce.tasks</name> > <value>3</value> > </property> > --> > > <property> > <name>fs.inmemory.size.mb</name> > <value>200</value> > </property> > > <property> > <name>dfs.block.size</name> > <value>134217728</value> > </property> > > <property> > <name>io.sort.factor</name> > <value>100</value> > </property> > > <property> > <name>io.sort.mb</name> > <value>200</value> > </property> > > <property> > <name>io.file.buffer.size</name> > <value>131072</value> > </property> > > </configuration> > > |
|
|
Re: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
Yes, it looks like HADOOP-1374 The program actually failed after a while: gu@ncdm-8:~/hadoop-0.15.2$ ./bin/hadoop jar hadoop-0.15.2-test.jar mrbench MRBenchmark.0.0.2 08/01/18 18:53:08 INFO mapred.MRBench: creating control file: 1 numLines, ASCENDING sortOrder 08/01/18 18:53:08 INFO mapred.MRBench: created control file: /benchmarks/MRBench/mr_input/input_-450753747.txt 08/01/18 18:53:09 INFO mapred.MRBench: Running job 0: input=/benchmarks/MRBench/mr_input output=/benchmarks/MRBench/mr_output/output_1843693325 08/01/18 18:53:09 INFO mapred.FileInputFormat: Total input paths to process : 1 08/01/18 18:53:09 INFO mapred.JobClient: Running job: job_200801181852_0001 08/01/18 18:53:10 INFO mapred.JobClient: map 0% reduce 0% 08/01/18 18:53:17 INFO mapred.JobClient: map 100% reduce 0% 08/01/18 18:53:25 INFO mapred.JobClient: map 100% reduce 16% 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : task_200801181852_0001_m_000001_0, Status : FAILED Too many fetch-failures 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task outputncdm15 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task outputncdm15 08/01/18 19:08:34 INFO mapred.JobClient: map 100% reduce 100% 08/01/18 19:08:35 INFO mapred.JobClient: Job complete: job_200801181852_0001 08/01/18 19:08:35 INFO mapred.JobClient: Counters: 10 08/01/18 19:08:35 INFO mapred.JobClient: Job Counters 08/01/18 19:08:35 INFO mapred.JobClient: Launched map tasks=3 08/01/18 19:08:35 INFO mapred.JobClient: Launched reduce tasks=1 08/01/18 19:08:35 INFO mapred.JobClient: Data-local map tasks=2 08/01/18 19:08:35 INFO mapred.JobClient: Map-Reduce Framework 08/01/18 19:08:35 INFO mapred.JobClient: Map input records=1 08/01/18 19:08:35 INFO mapred.JobClient: Map output records=1 08/01/18 19:08:35 INFO mapred.JobClient: Map input bytes=2 08/01/18 19:08:35 INFO mapred.JobClient: Map output bytes=5 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input groups=1 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input records=1 08/01/18 19:08:35 INFO mapred.JobClient: Reduce output records=1 DataLines Maps Reduces AvgTime (milliseconds) 1 2 1 926333 On Fri, 18 Jan 2008, Konstantin Shvachko wrote: > Looks like we still have this unsolved mysterious problem: > > http://issues.apache.org/jira/browse/HADOOP-1374 > > Could it be related to HADOOP-1246? Arun? > > Thanks, > --Konstantin > > Yunhong Gu1 wrote: >> >> Hi, >> >> If someone knows how to fix the problem described below, please help me >> out. Thanks! >> >> I am testing Hadoop on 2-node cluster and the "reduce" always hangs at some >> stage, even if I use different clusters. My OS is Debian Linux kernel 2.6 >> (AMD Opteron w/ 4GB Mem). Hadoop verision is 0.15.2. Java version is >> 1.5.0_01-b08. >> >> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar mrbench" and when >> the map stage finishes, the reduce stage will hang somewhere in the middle, >> sometimes at 0%. I also tried any other mapreduce program I can find in the >> example jar package but they all hang. >> >> The log file simply print >> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >> >> forever. >> >> The program does work if I start Hadoop only on single node. >> >> Below is my hadoop-site.xml configuration: >> >> <configuration> >> >> <property> >> <name>fs.default.name</name> >> <value>10.0.0.1:60000</value> >> </property> >> >> <property> >> <name>mapred.job.tracker</name> >> <value>10.0.0.1:60001</value> >> </property> >> >> <property> >> <name>dfs.data.dir</name> >> <value>/raid/hadoop/data</value> >> </property> >> >> <property> >> <name>mapred.local.dir</name> >> <value>/raid/hadoop/mapred</value> >> </property> >> >> <property> >> <name>hadoop.tmp.dir</name> >> <value>/raid/hadoop/tmp</value> >> </property> >> >> <property> >> <name>mapred.child.java.opts</name> >> <value>-Xmx1024m</value> >> </property> >> >> <property> >> <name>mapred.tasktracker.tasks.maximum</name> >> <value>4</value> >> </property> >> >> <!-- >> <property> >> <name>mapred.map.tasks</name> >> <value>7</value> >> </property> >> >> <property> >> <name>mapred.reduce.tasks</name> >> <value>3</value> >> </property> >> --> >> >> <property> >> <name>fs.inmemory.size.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>dfs.block.size</name> >> <value>134217728</value> >> </property> >> >> <property> >> <name>io.sort.factor</name> >> <value>100</value> >> </property> >> >> <property> >> <name>io.sort.mb</name> >> <value>200</value> >> </property> >> >> <property> >> <name>io.file.buffer.size</name> >> <value>131072</value> >> </property> >> >> </configuration> >> >> > |
|
|
RE: Reduce hangs
by Devaraj Das
::
Rate this Message:
Hi Yunhong,
As per the output it seems the job ran to successful completion (albeit with some failures)... Devaraj > -----Original Message----- > From: Yunhong Gu1 [mailto:ygu1@...] > Sent: Saturday, January 19, 2008 8:56 AM > To: hadoop-user@... > Subject: Re: Reduce hangs > > > > Yes, it looks like HADOOP-1374 > > The program actually failed after a while: > > > gu@ncdm-8:~/hadoop-0.15.2$ ./bin/hadoop jar > hadoop-0.15.2-test.jar mrbench > MRBenchmark.0.0.2 > 08/01/18 18:53:08 INFO mapred.MRBench: creating control file: > 1 numLines, ASCENDING sortOrder > 08/01/18 18:53:08 INFO mapred.MRBench: created control file: > /benchmarks/MRBench/mr_input/input_-450753747.txt > 08/01/18 18:53:09 INFO mapred.MRBench: Running job 0: > input=/benchmarks/MRBench/mr_input > output=/benchmarks/MRBench/mr_output/output_1843693325 > 08/01/18 18:53:09 INFO mapred.FileInputFormat: Total input > paths to process : 1 > 08/01/18 18:53:09 INFO mapred.JobClient: Running job: > job_200801181852_0001 > 08/01/18 18:53:10 INFO mapred.JobClient: map 0% reduce 0% > 08/01/18 18:53:17 INFO mapred.JobClient: map 100% reduce 0% > 08/01/18 18:53:25 INFO mapred.JobClient: map 100% reduce 16% > 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : > task_200801181852_0001_m_000001_0, Status : FAILED Too many > fetch-failures > 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task > outputncdm15 > 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task > outputncdm15 > 08/01/18 19:08:34 INFO mapred.JobClient: map 100% reduce 100% > 08/01/18 19:08:35 INFO mapred.JobClient: Job complete: > job_200801181852_0001 > 08/01/18 19:08:35 INFO mapred.JobClient: Counters: 10 > 08/01/18 19:08:35 INFO mapred.JobClient: Job Counters > 08/01/18 19:08:35 INFO mapred.JobClient: Launched map tasks=3 > 08/01/18 19:08:35 INFO mapred.JobClient: Launched reduce tasks=1 > 08/01/18 19:08:35 INFO mapred.JobClient: Data-local map tasks=2 > 08/01/18 19:08:35 INFO mapred.JobClient: Map-Reduce Framework > 08/01/18 19:08:35 INFO mapred.JobClient: Map input records=1 > 08/01/18 19:08:35 INFO mapred.JobClient: Map output records=1 > 08/01/18 19:08:35 INFO mapred.JobClient: Map input bytes=2 > 08/01/18 19:08:35 INFO mapred.JobClient: Map output bytes=5 > 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input groups=1 > 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input records=1 > 08/01/18 19:08:35 INFO mapred.JobClient: Reduce output records=1 > DataLines Maps Reduces AvgTime (milliseconds) > 1 2 1 926333 > > > > On Fri, 18 Jan 2008, Konstantin Shvachko wrote: > > > Looks like we still have this unsolved mysterious problem: > > > > http://issues.apache.org/jira/browse/HADOOP-1374 > > > > Could it be related to HADOOP-1246? Arun? > > > > Thanks, > > --Konstantin > > > > Yunhong Gu1 wrote: > >> > >> Hi, > >> > >> If someone knows how to fix the problem described below, > please help > >> me out. Thanks! > >> > >> I am testing Hadoop on 2-node cluster and the "reduce" > always hangs > >> at some stage, even if I use different clusters. My OS is Debian > >> Linux kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision > is 0.15.2. > >> Java version is 1.5.0_01-b08. > >> > >> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar > mrbench" and > >> when the map stage finishes, the reduce stage will hang > somewhere in > >> the middle, sometimes at 0%. I also tried any other > mapreduce program > >> I can find in the example jar package but they all hang. > >> > >> The log file simply print > >> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: > >> task_200801181424_0004_r_000000_0 0.0% reduce > copy > > >> > >> forever. > >> > >> The program does work if I start Hadoop only on single node. > >> > >> Below is my hadoop-site.xml configuration: > >> > >> <configuration> > >> > >> <property> > >> <name>fs.default.name</name> > >> <value>10.0.0.1:60000</value> > >> </property> > >> > >> <property> > >> <name>mapred.job.tracker</name> > >> <value>10.0.0.1:60001</value> > >> </property> > >> > >> <property> > >> <name>dfs.data.dir</name> > >> <value>/raid/hadoop/data</value> > >> </property> > >> > >> <property> > >> <name>mapred.local.dir</name> > >> <value>/raid/hadoop/mapred</value> > >> </property> > >> > >> <property> > >> <name>hadoop.tmp.dir</name> > >> <value>/raid/hadoop/tmp</value> > >> </property> > >> > >> <property> > >> <name>mapred.child.java.opts</name> > >> <value>-Xmx1024m</value> > >> </property> > >> > >> <property> > >> <name>mapred.tasktracker.tasks.maximum</name> > >> <value>4</value> > >> </property> > >> > >> <!-- > >> <property> > >> <name>mapred.map.tasks</name> > >> <value>7</value> > >> </property> > >> > >> <property> > >> <name>mapred.reduce.tasks</name> > >> <value>3</value> > >> </property> > >> --> > >> > >> <property> > >> <name>fs.inmemory.size.mb</name> > >> <value>200</value> > >> </property> > >> > >> <property> > >> <name>dfs.block.size</name> > >> <value>134217728</value> > >> </property> > >> > >> <property> > >> <name>io.sort.factor</name> > >> <value>100</value> > >> </property> > >> > >> <property> > >> <name>io.sort.mb</name> > >> <value>200</value> > >> </property> > >> > >> <property> > >> <name>io.file.buffer.size</name> > >> <value>131072</value> > >> </property> > >> > >> </configuration> > >> > >> > > > |
|
|
RE: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
Oh, so it is the task running on the other node (ncdm-15) fails and Hadoop re-run the task on the local node (ncdm-8). (I only have two nodes, ncdm-8 and ncdm-15. Both namenode and jobtracker are running on ncdm-8. The program is also started on ncdm-8). >> 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : task_200801181852_0001_m_000001_0, Status : FAILED Too many fetch-failures >> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task outputncdm15 Any ideas why the task would fail? And why it takes so long for Hadoop to detect the failure? Thanks Yunhong On Sat, 19 Jan 2008, Devaraj Das wrote: > Hi Yunhong, > As per the output it seems the job ran to successful completion (albeit with > some failures)... > Devaraj > >> -----Original Message----- >> From: Yunhong Gu1 [mailto:ygu1@...] >> Sent: Saturday, January 19, 2008 8:56 AM >> To: hadoop-user@... >> Subject: Re: Reduce hangs >> >> >> >> Yes, it looks like HADOOP-1374 >> >> The program actually failed after a while: >> >> >> gu@ncdm-8:~/hadoop-0.15.2$ ./bin/hadoop jar >> hadoop-0.15.2-test.jar mrbench >> MRBenchmark.0.0.2 >> 08/01/18 18:53:08 INFO mapred.MRBench: creating control file: >> 1 numLines, ASCENDING sortOrder >> 08/01/18 18:53:08 INFO mapred.MRBench: created control file: >> /benchmarks/MRBench/mr_input/input_-450753747.txt >> 08/01/18 18:53:09 INFO mapred.MRBench: Running job 0: >> input=/benchmarks/MRBench/mr_input >> output=/benchmarks/MRBench/mr_output/output_1843693325 >> 08/01/18 18:53:09 INFO mapred.FileInputFormat: Total input >> paths to process : 1 >> 08/01/18 18:53:09 INFO mapred.JobClient: Running job: >> job_200801181852_0001 >> 08/01/18 18:53:10 INFO mapred.JobClient: map 0% reduce 0% >> 08/01/18 18:53:17 INFO mapred.JobClient: map 100% reduce 0% >> 08/01/18 18:53:25 INFO mapred.JobClient: map 100% reduce 16% >> 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : >> task_200801181852_0001_m_000001_0, Status : FAILED Too many >> fetch-failures >> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task >> outputncdm15 >> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task >> outputncdm15 >> 08/01/18 19:08:34 INFO mapred.JobClient: map 100% reduce 100% >> 08/01/18 19:08:35 INFO mapred.JobClient: Job complete: >> job_200801181852_0001 >> 08/01/18 19:08:35 INFO mapred.JobClient: Counters: 10 >> 08/01/18 19:08:35 INFO mapred.JobClient: Job Counters >> 08/01/18 19:08:35 INFO mapred.JobClient: Launched map tasks=3 >> 08/01/18 19:08:35 INFO mapred.JobClient: Launched reduce tasks=1 >> 08/01/18 19:08:35 INFO mapred.JobClient: Data-local map tasks=2 >> 08/01/18 19:08:35 INFO mapred.JobClient: Map-Reduce Framework >> 08/01/18 19:08:35 INFO mapred.JobClient: Map input records=1 >> 08/01/18 19:08:35 INFO mapred.JobClient: Map output records=1 >> 08/01/18 19:08:35 INFO mapred.JobClient: Map input bytes=2 >> 08/01/18 19:08:35 INFO mapred.JobClient: Map output bytes=5 >> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input groups=1 >> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input records=1 >> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce output records=1 >> DataLines Maps Reduces AvgTime (milliseconds) >> 1 2 1 926333 >> >> >> >> On Fri, 18 Jan 2008, Konstantin Shvachko wrote: >> >>> Looks like we still have this unsolved mysterious problem: >>> >>> http://issues.apache.org/jira/browse/HADOOP-1374 >>> >>> Could it be related to HADOOP-1246? Arun? >>> >>> Thanks, >>> --Konstantin >>> >>> Yunhong Gu1 wrote: >>>> >>>> Hi, >>>> >>>> If someone knows how to fix the problem described below, >> please help >>>> me out. Thanks! >>>> >>>> I am testing Hadoop on 2-node cluster and the "reduce" >> always hangs >>>> at some stage, even if I use different clusters. My OS is Debian >>>> Linux kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision >> is 0.15.2. >>>> Java version is 1.5.0_01-b08. >>>> >>>> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar >> mrbench" and >>>> when the map stage finishes, the reduce stage will hang >> somewhere in >>>> the middle, sometimes at 0%. I also tried any other >> mapreduce program >>>> I can find in the example jar package but they all hang. >>>> >>>> The log file simply print >>>> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>> >>>> forever. >>>> >>>> The program does work if I start Hadoop only on single node. >>>> >>>> Below is my hadoop-site.xml configuration: >>>> >>>> <configuration> >>>> >>>> <property> >>>> <name>fs.default.name</name> >>>> <value>10.0.0.1:60000</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.job.tracker</name> >>>> <value>10.0.0.1:60001</value> >>>> </property> >>>> >>>> <property> >>>> <name>dfs.data.dir</name> >>>> <value>/raid/hadoop/data</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.local.dir</name> >>>> <value>/raid/hadoop/mapred</value> >>>> </property> >>>> >>>> <property> >>>> <name>hadoop.tmp.dir</name> >>>> <value>/raid/hadoop/tmp</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.child.java.opts</name> >>>> <value>-Xmx1024m</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.tasktracker.tasks.maximum</name> >>>> <value>4</value> >>>> </property> >>>> >>>> <!-- >>>> <property> >>>> <name>mapred.map.tasks</name> >>>> <value>7</value> >>>> </property> >>>> >>>> <property> >>>> <name>mapred.reduce.tasks</name> >>>> <value>3</value> >>>> </property> >>>> --> >>>> >>>> <property> >>>> <name>fs.inmemory.size.mb</name> >>>> <value>200</value> >>>> </property> >>>> >>>> <property> >>>> <name>dfs.block.size</name> >>>> <value>134217728</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.sort.factor</name> >>>> <value>100</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.sort.mb</name> >>>> <value>200</value> >>>> </property> >>>> >>>> <property> >>>> <name>io.file.buffer.size</name> >>>> <value>131072</value> >>>> </property> >>>> >>>> </configuration> >>>> >>>> >>> >> > > |
|
|
RE: Reduce hangs
by Yunhong Gu1
::
Rate this Message:
Hi, all Just to keep this topic updated :) I am still tring to figure what happened. I found that in my 2-node configuration (namenode and jobtracker on node-1, while both are datanodes and tasktrackers). The reduce task may sometimes (but rarely) complete for programs that needs small amount of CPU time (e.g., mrbench), but for programs with large computation, it never finish. When reduces blocks, it always fails at 16%. Eventually I will get this error information: 08/01/18 15:01:27 WARN mapred.JobClient: Error reading task outputncdm-IPxxxxxxxxx 08/01/18 15:01:27 WARN mapred.JobClient: Error reading task outputncdm-IPxxxxxxxxx 08/01/18 15:13:38 INFO mapred.JobClient: Task Id : task_200801181145_0005_r_000000_1, Status : FAILED Shuffle Error: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out. 08/01/18 19:56:38 WARN mapred.JobClient: Error reading task outputConnection timed out 08/01/18 19:59:47 WARN mapred.JobClient: Error reading task outputConnection timed out 08/01/18 20:09:40 INFO mapred.JobClient: map 100% reduce 100% java.io.IOException: Job failed! I found that "IPxxxxxxxx" is not the correct network address that Hadoop should read result from. The servers I use have 2 network interfaces and I am using another one. I explicitly fill the IP addresses 10.0.0.x in all the configuration files. Might this be the reason of Reduce failure? But the Map phase does work. Thanks Yunhong On Sat, 19 Jan 2008, Yunhong Gu1 wrote: > > Oh, so it is the task running on the other node (ncdm-15) fails and Hadoop > re-run the task on the local node (ncdm-8). (I only have two nodes, ncdm-8 > and ncdm-15. Both namenode and jobtracker are running on ncdm-8. The program > is also started on ncdm-8). > >>> 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : >>> task_200801181852_0001_m_000001_0, Status : FAILED Too many fetch-failures >>> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task outputncdm15 > > Any ideas why the task would fail? And why it takes so long for Hadoop to > detect the failure? > > Thanks > Yunhong > > On Sat, 19 Jan 2008, Devaraj Das wrote: > >> Hi Yunhong, >> As per the output it seems the job ran to successful completion (albeit >> with >> some failures)... >> Devaraj >> >>> -----Original Message----- >>> From: Yunhong Gu1 [mailto:ygu1@...] >>> Sent: Saturday, January 19, 2008 8:56 AM >>> To: hadoop-user@... >>> Subject: Re: Reduce hangs >>> >>> >>> >>> Yes, it looks like HADOOP-1374 >>> >>> The program actually failed after a while: >>> >>> >>> gu@ncdm-8:~/hadoop-0.15.2$ ./bin/hadoop jar >>> hadoop-0.15.2-test.jar mrbench >>> MRBenchmark.0.0.2 >>> 08/01/18 18:53:08 INFO mapred.MRBench: creating control file: >>> 1 numLines, ASCENDING sortOrder >>> 08/01/18 18:53:08 INFO mapred.MRBench: created control file: >>> /benchmarks/MRBench/mr_input/input_-450753747.txt >>> 08/01/18 18:53:09 INFO mapred.MRBench: Running job 0: >>> input=/benchmarks/MRBench/mr_input >>> output=/benchmarks/MRBench/mr_output/output_1843693325 >>> 08/01/18 18:53:09 INFO mapred.FileInputFormat: Total input >>> paths to process : 1 >>> 08/01/18 18:53:09 INFO mapred.JobClient: Running job: >>> job_200801181852_0001 >>> 08/01/18 18:53:10 INFO mapred.JobClient: map 0% reduce 0% >>> 08/01/18 18:53:17 INFO mapred.JobClient: map 100% reduce 0% >>> 08/01/18 18:53:25 INFO mapred.JobClient: map 100% reduce 16% >>> 08/01/18 19:08:27 INFO mapred.JobClient: Task Id : >>> task_200801181852_0001_m_000001_0, Status : FAILED Too many >>> fetch-failures >>> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task >>> outputncdm15 >>> 08/01/18 19:08:27 WARN mapred.JobClient: Error reading task >>> outputncdm15 >>> 08/01/18 19:08:34 INFO mapred.JobClient: map 100% reduce 100% >>> 08/01/18 19:08:35 INFO mapred.JobClient: Job complete: >>> job_200801181852_0001 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Counters: 10 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Job Counters >>> 08/01/18 19:08:35 INFO mapred.JobClient: Launched map tasks=3 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Launched reduce tasks=1 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Data-local map tasks=2 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Map-Reduce Framework >>> 08/01/18 19:08:35 INFO mapred.JobClient: Map input records=1 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Map output records=1 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Map input bytes=2 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Map output bytes=5 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input groups=1 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce input records=1 >>> 08/01/18 19:08:35 INFO mapred.JobClient: Reduce output records=1 >>> DataLines Maps Reduces AvgTime (milliseconds) >>> 1 2 1 926333 >>> >>> >>> >>> On Fri, 18 Jan 2008, Konstantin Shvachko wrote: >>> >>>> Looks like we still have this unsolved mysterious problem: >>>> >>>> http://issues.apache.org/jira/browse/HADOOP-1374 >>>> >>>> Could it be related to HADOOP-1246? Arun? >>>> >>>> Thanks, >>>> --Konstantin >>>> >>>> Yunhong Gu1 wrote: >>>>> >>>>> Hi, >>>>> >>>>> If someone knows how to fix the problem described below, >>> please help >>>>> me out. Thanks! >>>>> >>>>> I am testing Hadoop on 2-node cluster and the "reduce" >>> always hangs >>>>> at some stage, even if I use different clusters. My OS is Debian >>>>> Linux kernel 2.6 (AMD Opteron w/ 4GB Mem). Hadoop verision >>> is 0.15.2. >>>>> Java version is 1.5.0_01-b08. >>>>> >>>>> I simply tried "./bin/hadoop jar hadoop-0.15.2-test.jar >>> mrbench" and >>>>> when the map stage finishes, the reduce stage will hang >>> somewhere in >>>>> the middle, sometimes at 0%. I also tried any other >>> mapreduce program >>>>> I can find in the example jar package but they all hang. >>>>> >>>>> The log file simply print >>>>> 2008-01-18 15:15:50,831 INFO org.apache.hadoop.mapred.TaskTracker: >>>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>>> 2008-01-18 15:15:56,841 INFO org.apache.hadoop.mapred.TaskTracker: >>>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>>> 2008-01-18 15:16:02,850 INFO org.apache.hadoop.mapred.TaskTracker: >>>>> task_200801181424_0004_r_000000_0 0.0% reduce > copy > >>>>> >>>>> forever. >>>>> >>>>> The program does work if I start Hadoop only on single node. >>>>> >>>>> Below is my hadoop-site.xml configuration: >>>>> >>>>> <configuration> >>>>> >>>>> <property> >>>>> <name>fs.default.name</name> >>>>> <value>10.0.0.1:60000</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>mapred.job.tracker</name> >>>>> <value>10.0.0.1:60001</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>dfs.data.dir</name> >>>>> <value>/raid/hadoop/data</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>mapred.local.dir</name> >>>>> <value>/raid/hadoop/mapred</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>hadoop.tmp.dir</name> >>>>> <value>/raid/hadoop/tmp</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>mapred.child.java.opts</name> >>>>> <value>-Xmx1024m</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>mapred.tasktracker.tasks.maximum</name> >>>>> <value>4</value> >>>>> </property> >>>>> >>>>> <!-- >>>>> <property> >>>>> <name>mapred.map.tasks</name> >>>>> <value>7</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>mapred.reduce.tasks</name> >>>>> <value>3</value> >>>>> </property> >>>>> --> >>>>> >>>>> <property> >>>>> <name>fs.inmemory.size.mb</name> >>>>> <value>200</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>dfs.block.size</name> >>>>> <value>134217728</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>io.sort.factor</name> >>>>> <value>100</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>io.sort.mb</name> >>>>> <value>200</value> >>>>> </property> >>>>> >>>>> <property> >>>>> <name>io.file.buffer.size</name> >>>>> <value>131072</value> >>>>> </property> >>>>> >>>>> </configuration> >>>>> >>>>> >>>> >>> >> >> > |
| Free embeddable forum powered by Nabble | Forum Help |
