Hadoop 2.3.0 wordcount runs forever - hadoop

I am trying to test my hadoop installation by running a wordcount job. My problem is that the job gets stuck at ACCEPTED state and seems to run forever. I am using hadoop 2.3.0 and tried fix the problem by following an answer to this question here but it didn't work for me.
This is what I have:
C:\hadoop-2.3.0>yarn jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.3.0.jar wordcount /data/test.txt /data/output
15/03/15 15:36:07 INFO client.RMProxy: Connecting to ResourceManager at/0.0.0.0:8032
15/03/15 15:36:09 INFO input.FileInputFormat: Total input paths to process : 1
15/03/15 15:36:10 INFO mapreduce.JobSubmitter: number of splits:1
15/03/15 15:36:10 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_14 26430101974_0001
15/03/15 15:36:11 INFO impl.YarnClientImpl: Submitted application application_14 26430101974_0001
15/03/15 15:36:11 INFO mapreduce.Job: The url to track the job: http://Agata-PC:8088/proxy/application_1426430101974_0001/
15/03/15 15:36:11 INFO mapreduce.Job: Running job: job_1426430101974_0001
This is my mapred-site.xml:
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapred.job.tracker</name>
<value>127.0.0.1:9001</value>
</property>
<property>
<name>mapreduce.jobtracker.staging.root.dir</name>
<value>/user</value>
</property>
<property>
<name>mapreduce.history.server.http.address</name>
<value>127.0.0.1:51111</value>
<description>Http address of the history server</description>
<final>false</final>
</property>
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>1024</value>
</property>
<property>
<name>yarn.app.mapreduce.am.command-opts</name>
<value>-Xmx768m</value>
</property>
<property>
<name>mapreduce.map.cpu.vcores</name>
<value>1</value>
<description>The number of virtual cores required for each map task.</description>
</property>
<property>
<name>mapreduce.reduce.cpu.vcores</name>
<value>1</value>
<description>The number of virtual cores required for each map task.</description>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>1024</value>
<description>Larger resource limit for maps.</description>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx768m</value>
<description>Heap-size for child jvms of maps.</description>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>1024</value>
<description>Larger resource limit for reduces.</description>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx768m</value>
<description>Heap-size for child jvms of reduces.</description>
</property>
</configuration>
And this is my yarn-site.xml:
<configuration>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>128</value>
<description>Minimum limit of memory to allocate to each container request at the Resource Manager.</description>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-vcores</name>
<value>1</value>
<description>The minimum allocation for every container request at the RM, in terms of virtual CPU cores. Requests lower than this won't take effect, and the specified value will get allocated the minimum.</description>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-vcores</name>
<value>2</value>
<description>The maximum allocation for every container request at the RM, in terms of virtual CPU cores. Requests higher than this won't take effect, and will get capped to this value.</description>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>2048</value>
<description>Physical memory, in MB, to be made available to running containers</description>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>4</value>
<description>Number of CPU cores that can be allocated for containers.</description>
</property>
</configuration>
Any help is much appreciated.

Did you try restarting your hadoop's processes or clusters? There might be some works still running.
May be it will be helpful to see the log by following the url of the job or by going through the hadoop url.
Cheers.

I have run into similar issue earlier, you might have a infinite loop in mapper or reducer . Check if your reducer is properly handling iterable.

Related

Hadoop Cluster - Zero Memory

I have two VM setup for the Hadoop cluster, as below.
VM-MASTER, 4GB Memory
VM-SLAVE, 4GB Memory
I have the following config for yarn-site.xml. When I goto http://VM-MASTEr:8088/cluster. I see Memory Total is 0, and VCores Total is 0.
Am I missing something here?
I think this problem caused the job I submitted always in ACCEPTED state, and never move into RUNNING state. I'm using Hadoop 2.8.0.
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>500</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>2048</value>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>1</value>
</property>
</configuration>

nodemanager is not starting while upgrading to hadoop 2 from hadoop classic

I have one master one worker cluster. I am upgrading to YARN from Hadoop classic. resourcemanager and historyserver successfully started, but nodemanager is not starting it is giving error
java.lang.NumberFormatException: For input string: "${nodemanager.resource.memory-mb}"
I have kept same yarn-site.xml.template in both server.
I have replaced ${nodemanager.resource.memory-mb} to 8192
<configuration>
<property>
<name>yarn.resourcemanager.hostname</name>
<value>__RM_IP__</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>${yarn.resourcemanager.hostname}:8030</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>${yarn.resourcemanager.hostname}:8031</value>
</property>
<property>
<name>yarn.resourcemanager.address</name>
<value>${yarn.resourcemanager.hostname}:8032</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>${nodemanager.resource.memory-mb}</value>
</property>
</configuration></br>

MapReduce job hangs, waiting for AM container to be allocated

I tried to run simple word count as MapReduce job. Everything works fine when run locally (all work done on Name Node). But, when I try to run it on a cluster using YARN (adding mapreduce.framework.name=yarn to mapred-site.conf) job hangs.
I came across a similar problem here:
MapReduce jobs get stuck in Accepted state
Output from job:
*** START ***
15/12/25 17:52:50 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:8032
15/12/25 17:52:51 WARN mapreduce.JobResourceUploader: Hadoop command-line option parsing not performed. Implement the Tool interface and execute your application with ToolRunner to remedy this.
15/12/25 17:52:51 INFO input.FileInputFormat: Total input paths to process : 5
15/12/25 17:52:52 INFO mapreduce.JobSubmitter: number of splits:5
15/12/25 17:52:52 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1451083949804_0001
15/12/25 17:52:53 INFO impl.YarnClientImpl: Submitted application application_1451083949804_0001
15/12/25 17:52:53 INFO mapreduce.Job: The url to track the job: http://hadoop-droplet:8088/proxy/application_1451083949804_0001/
15/12/25 17:52:53 INFO mapreduce.Job: Running job: job_1451083949804_0001
mapred-site.xml:
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapreduce.job.tracker</name>
<value>localhost:54311</value>
</property>
<!--
<property>
<name>mapreduce.job.tracker.reserved.physicalmemory.mb</name>
<value></value>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>1024</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>2048</value>
</property>
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>3000</value>
<source>mapred-site.xml</source>
</property> -->
</configuration>
yarn-site.xml
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
<!--
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>3000</value>
<source>yarn-site.xml</source>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>500</value>
</property>
<property>
<name>yarn.scheduler.capacity.maximum-am-resource-percent</name>
<value>3000</value>
</property>
-->
</configuration>
//I the left commented options - they were not solving the problem
YarnApplicationState: ACCEPTED: waiting for AM container to be allocated, launched and register with RM.
What can be the problem?
EDIT:
I tried this configuration (commented) on machines: NameNode(8GB RAM) + 2x DataNode (4GB RAM). I get the same effect: Job hangs on ACCEPTED state.
EDIT2:
changed configuration (thanks #Manjunath Ballur) to:
yarn-site.xml:
<configuration>
<property>
<name>yarn.resourcemanager.hostname</name>
<value>hadoop-droplet</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>hadoop-droplet:8031</value>
</property>
<property>
<name>yarn.resourcemanager.address</name>
<value>hadoop-droplet:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>hadoop-droplet:8030</value>
</property>
<property>
<name>yarn.resourcemanager.admin.address</name>
<value>hadoop-droplet:8033</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address</name>
<value>hadoop-droplet:8088</value>
</property>
<property>
<description>Classpath for typical applications.</description>
<name>yarn.application.classpath</name>
<value>
$HADOOP_CONF_DIR,
$HADOOP_COMMON_HOME/*,$HADOOP_COMMON_HOME/lib/*,
$HADOOP_HDFS_HOME/*,$HADOOP_HDFS_HOME/lib/*,
$HADOOP_MAPRED_HOME/*,$HADOOP_MAPRED_HOME/lib/*,
$YARN_HOME/*,$YARN_HOME/lib/*
</value>
</property>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce.shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
<property>
<name>yarn.nodemanager.local-dirs</name>
<value>/data/1/yarn/local,/data/2/yarn/local,/data/3/yarn/local</value>
</property>
<property>
<name>yarn.nodemanager.log-dirs</name>
<value>/data/1/yarn/logs,/data/2/yarn/logs,/data/3/yarn/logs</value>
</property>
<property>
<description>Where to aggregate logs</description>
<name>yarn.nodemanager.remote-app-log-dir</name>
<value>/var/log/hadoop-yarn/apps</value>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>50</value>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-mb</name>
<value>390</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>390</value>
</property>
</configuration>
mapred-site.xml:
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>50</value>
</property>
<property>
<name>yarn.app.mapreduce.am.command-opts</name>
<value>-Xmx40m</value>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>50</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>50</value>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx40m</value>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx40m</value>
</property>
</configuration>
Still not working.
Additional info: I can see no nodes on cluster preview (similar problem here: Slave nodes not in Yarn ResourceManager )
You should check the status of Node managers in your cluster. If the NM nodes are short on disk space then RM will mark them "unhealthy" and those NMs can't allocate new containers.
1) Check the Unhealthy nodes: http://<active_RM>:8088/cluster/nodes/unhealthy
If the "health report" tab says "local-dirs are bad" then it means you need to cleanup some disk space from these nodes.
2) Check the DFS dfs.data.dir property in hdfs-site.xml. It points the location on local file system where hdfs data is stored.
3) Login to those machines and use df -h & hadoop fs - du -h commands to measure the space occupied.
4) Verify hadoop trash and delete it if it's blocking you.
hadoop fs -du -h /user/user_name/.Trash and hadoop fs -rm -r /user/user_name/.Trash/*
I feel, you are getting your memory settings wrong.
To understand the tuning of YARN configuration, I found this to be a very good source: http://www.cloudera.com/content/www/en-us/documentation/enterprise/latest/topics/cdh_ig_yarn_tuning.html
I followed the instructions given in this blog and was able to get my jobs running. You should alter your settings proportional to the physical memory you have on your nodes.
Key things to remember is:
Values of mapreduce.map.memory.mb and mapreduce.reduce.memory.mb should be at least yarn.scheduler.minimum-allocation-mb
Values of mapreduce.map.java.opts and mapreduce.reduce.java.opts should be around "0.8 times the value of" corresponding mapreduce.map.memory.mb and mapreduce.reduce.memory.mb configurations. (In my case it is 983 MB ~ (0.8 * 1228 MB))
Similarly, value of yarn.app.mapreduce.am.command-opts should be "0.8 times the value of" yarn.app.mapreduce.am.resource.mb
Following are the settings I use and they work perfectly for me:
yarn-site.xml:
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>1228</value>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-mb</name>
<value>9830</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>9830</value>
</property>
mapred-site.xml
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>1228</value>
</property>
<property>
<name>yarn.app.mapreduce.am.command-opts</name>
<value>-Xmx983m</value>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>1228</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>1228</value>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx983m</value>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx983m</value>
</property>
You can also refer to the answer here: Yarn container understanding and tuning
You can add vCore settings, if you want your container allocation to take into account CPU also. But, for this to work, you need to use CapacityScheduler with DominantResourceCalculator. See the discussion about this here: How are containers created based on vcores and memory in MapReduce2?
This has solved my case for this error:
<property>
<name>yarn.scheduler.capacity.maximum-am-resource-percent</name>
<value>100</value>
</property>
Check your hosts file on master and slave nodes. I had exactly this problem. My hosts file looked like this on master node for example
127.0.0.0 localhost
127.0.1.1 master-virtualbox
192.168.15.101 master
I changed it like below
192.168.15.101 master master-virtualbox localhost
So it worked.
These lines
<property>
<name>yarn.nodemanager.disk-health-checker.max-disk-utilization-per-disk-percentage</name>
<value>100</value>
</property>
in the yarn-site.xml solved my problem since the node will be marked as unhealthy when disk usage is >=95%. Solution mainly suitable for pseudodistributed mode.
You have 512 MB RAM on each of the instance and all your memory configurations in yarn-site.xml and mapred-site.xml are 500 MB to 3 GB. You will not be able to run any thing on the cluster. Change every thing to ~256 MB.
Also your mapred-site.xml is using framework to by yarn and you have job tracker address which is not correct. You need to have resource manager related parameters in yarn-site.xml on a multinode cluster (including resourcemanager web address). With out that, the cluster does not know where your cluster is.
You need to revisit both your xml files.
anyway that's work for me .thank you a lot! #KaP
that's my yarn-site.xml
<property>
<name>yarn.resourcemanager.hostname</name>
<value>MacdeMacBook-Pro.local</value>
</property>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address</name>
<value>${yarn.resourcemanager.hostname}:8088</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>4096</value>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>2048</value>
</property>
<property>
<name>yarn.nodemanager.vmem-pmem-ratio</name>
<value>2.1</value>
that's my mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
The first thing is to check yarn resource manager logs. I had searched the Internet about this problem for a very long time, but nobody told me how to find out what is really happening. It's so straightforward and simple to check yarn resource manager logs. I am confused why people ignore logs.
For me, there was a error in log
Caused by: org.apache.hadoop.net.ConnectTimeoutException: 20000 millis timeout while waiting for channel to be ready for connect. ch : java.nio.channels.SocketChannel[connection-pending remote=172.16.0.167/172.16.0.167:55622]
That's because I switched wifi network in my work place, so my computer IP changed.
Old question, but I got on the same issue recently and in my case it was due to manually setting the master to local in the code.
Please, search for conf.setMaster("local[*]") and remove it.
Hope it helps.

Hadoop Configuration for Raspberry Pi 2

I finally have got my Hadoop 2.6 running on rasbian on a RB Pi 2. I'm now going to tune it before deploying another node.
My current config is the pretty much default from a tutorial I've found on :
http://nextgenhadoop.blogspot.pt/2013/10/steps-to-install-hadoop-220-stable.html
And some troubleshooting tips from stackoverflow.
Due to the RAM available and CPU the Pi2 has, I'm sure there will be a 'ideal' config to it, I've been messing with yarn-site.xml adding and removing memory in a way that seems logical to me, but the Pi doesnt agree.
Right now I have 1 node, with '8 vcores' and '8GB' of ram. This can't of course be true
Can anyone share their config with me ?
These two propeties from yarn-site.xml file are relevant to nodemanager resources:
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>4096</value>
<description>Physical memory, in MB, to be made available to running containers</description>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>4</value>
<description>Number of CPU cores that can be allocated for containers.</description>
</property>
You can find more in Hadoop documentation
I've managed to trim it down, here is my congig, please feel free to comment on them. thanks
my yarn-site.xml
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>128</value>
<description>Minimum limit of memory to allocate to each container request at the Resource Manager.</description>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-mb</name>
<value>768</value>
<description>Maximum limit of memory to allocate to each container request at the Resource Manager.</description>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-vcores</name>
<value>1</value>
<description>The minimum allocation for every container request at the RM, in terms of virtual CPU cores. Requests lower than this won't take effect, and the specified value will get allocated the minimum.</description>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-vcores</name>
<value>2</value>
<description>The maximum allocation for every container request at the RM, in terms of virtual CPU cores. Requests higher than this won't take effect, and will get capped to this value.</description>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>768</value>
<description>Physical memory, in MB, to be made available to running containers</description>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>2</value>
<description>Number of CPU cores that can be allocated for containers.</description>
</property>
and my mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapred.job.tracker</name>
<value>hadoopi00:54311</value>
</property>
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>768</value>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>512</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>512</value>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx384m</value>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx384m</value>
</property>
</configuration>

pig script hang forever at heart beat

I had installed all components of cloudera 5 in one machine: name node, datanode, hue, pig, oozie , yarn, hbase ...
I run the following pig script in shell:
sudo -u hdfs pig
and then in the pig shell run
data = LOAD '/user/test/text.txt' as (text:CHARARRAY) ;
DUMP data;
script work well
But when run this script on hue browsers Query Editor/ Pig Editor it stuck and below is the log:
2015-09-14 14:07:06,847 [uber-SubtaskRunner] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - More information at: http://HadoopTestEnv:50030/jobdetails.jsp?jobid=job_1442214247855_0002
2015-09-14 14:07:06,884 [uber-SubtaskRunner] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - 0% complete
2015-09-14 14:07:07,512 [communication thread] INFO org.apache.hadoop.mapred.TaskAttemptListenerImpl - Progress of TaskAttempt attempt_1442214247855_0001_m_000000_0 is : 1.0
Heart beat
2015-09-14 14:07:37,545 [communication thread] INFO org.apache.hadoop.mapred.TaskAttemptListenerImpl - Progress of TaskAttempt attempt_1442214247855_0001_m_000000_0 is : 1.0
Heart beat
2015-09-14 14:08:07,571 [communication thread] INFO org.apache.hadoop.mapred.TaskAttemptListenerImpl - Progress of TaskAttempt attempt_1442214247855_0001_m_000000_0 is : 1.0
Heart beat
I have using the yarn-utils script to support me config the yarn-site.xml and marped-site.xml
python yarn-ulti.spy -c 6 -m 16 -d 1 -k True
Using cores=4 memory=16GB disks=1 hbase=True
Profile: cores=6 memory=12288MB reserved=4GB usableMem=12GB disks=1
Num Container=3
Container Ram=4096MB
Used Ram=12GB
Unused Ram=4GB
yarn.scheduler.minimum-allocation-mb=4096
yarn.scheduler.maximum-allocation-mb=12288
yarn.nodemanager.resource.memory-mb=12288
mapreduce.map.memory.mb=2048
mapreduce.map.java.opts=-Xmx1638m
mapreduce.reduce.memory.mb=4096
mapreduce.reduce.java.opts=-Xmx3276m
yarn.app.mapreduce.am.resource.mb=2048
yarn.app.mapreduce.am.command-opts=-Xmx1638m
mapreduce.task.io.sort.mb=819
Script still hang and heart beat forever , any one help me please !
Here is my config:
yarn-site.xml
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>12288</value>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>6</value>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>4096</value>
</property>
<property>
<name>yarn.scheduler.maximum-allocation-mb</name>
<value>12288</value>
</property>
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>2048</value>
</property>
<property>
<name>yarn.app.mapreduce.am.command-opts</name>
<value>-Xmx1638m</value>
</property>
Mapred-site.xml
<property>
<name>yarn.app.mapreduce.am.resource.mb</name>
<value>1024</value>
</property>
<property>
<name>yarn.app.mapreduce.am.command-opts</name>
<value>-Xmx768m</value>
</property>
<property>
<name>yarn.app.mapreduce.am.staging-dir</name>
<value>/user</value>
</property>
<property>
<name>mapreduce.map.java.opts</name>
<value>-Xmx1638m</value>
</property>
<property>
<name>mapreduce.reduce.java.opts</name>
<value>-Xmx3276m</value>
</property>
<property>
<name>mapreduce.map.memory.mb</name>
<value>2048</value>
</property>
<property>
<name>mapreduce.reduce.memory.mb</name>
<value>4096</value>
</property>
<property>
<name>mapreduce.task.io.sort.mb</name>
<value>819</value>
</property>
<property>
<name>mapreduce.map.cpu.vcores</name>
<value>2</value>
</property>
<property>
<name>mapreduce.reduce.cpu.vcores</name>
<value>2</value>
</property>
The Pig App submits an Oozie jobs that will use one MR slot in addition to what the script does.
The locking is usually due to submission deadlocks like gotcha #5 or having only one available task slot in your cluster.

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