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Amazon EMR
Developer Guide

Hadoop Configuration (Hadoop 20.205)

The following Amazon EMR default configuration settings for clusters launched with Amazon EMR AMI 2.0 or 2.1 are appropriate for most workloads.

If your cluster tasks are memory-intensive, you can enhance performance by using fewer tasks per core node and reducing your job tracker heap size.

The following tables list the default configuration settings for each EC2 instance type in clusters launched with the Amazon EMR AMI version 2.0 or 2.1. For more information about the AMI versions supported by Amazon EMR, see Choose an Amazon Machine Image (AMI).

m1.small

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 768
HADOOP_NAMENODE_HEAPSIZE 256
HADOOP_TASKTRACKER_HEAPSIZE 256
HADOOP_DATANODE_HEAPSIZE 128
mapred.child.java.opts -Xmx384m
mapred.tasktracker.map.tasks.maximum 2
mapred.tasktracker.reduce.tasks.maximum 1

m1.medium

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 1536
HADOOP_NAMENODE_HEAPSIZE 512
HADOOP_TASKTRACKER_HEAPSIZE 256
HADOOP_DATANODE_HEAPSIZE 256
mapred.child.java.opts -Xmx768m
mapred.tasktracker.map.tasks.maximum 2
mapred.tasktracker.reduce.tasks.maximum 1

m1.large

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 3072
HADOOP_NAMENODE_HEAPSIZE 1024
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx1152m
mapred.tasktracker.map.tasks.maximum 3
mapred.tasktracker.reduce.tasks.maximum 1

m1.xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 9216
HADOOP_NAMENODE_HEAPSIZE 3072
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx1024m
mapred.tasktracker.map.tasks.maximum 8
mapred.tasktracker.reduce.tasks.maximum 3

c1.medium

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 768
HADOOP_NAMENODE_HEAPSIZE 256
HADOOP_TASKTRACKER_HEAPSIZE 256
HADOOP_DATANODE_HEAPSIZE 128
mapred.child.java.opts -Xmx384m
mapred.tasktracker.map.tasks.maximum 2
mapred.tasktracker.reduce.tasks.maximum 1

c1.xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 3072
HADOOP_NAMENODE_HEAPSIZE 1024
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx512m
mapred.tasktracker.map.tasks.maximum 7
mapred.tasktracker.reduce.tasks.maximum 2

m2.xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 12288
HADOOP_NAMENODE_HEAPSIZE 4096
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx3072m
mapred.tasktracker.map.tasks.maximum 3
mapred.tasktracker.reduce.tasks.maximum 1

m2.2xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 24576
HADOOP_NAMENODE_HEAPSIZE 8192
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx3584m
mapred.tasktracker.map.tasks.maximum 6
mapred.tasktracker.reduce.tasks.maximum 2

m2.4xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 49152
HADOOP_NAMENODE_HEAPSIZE 16384
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx3072m
mapred.tasktracker.map.tasks.maximum 14
mapred.tasktracker.reduce.tasks.maximum 4

cc2.8xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 40152
HADOOP_NAMENODE_HEAPSIZE 16384
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx2048m
mapred.tasktracker.map.tasks.maximum 24
mapred.tasktracker.reduce.tasks.maximum 6

cg1.4xlarge

Parameter Value
HADOOP_JOBTRACKER_HEAPSIZE 10240
HADOOP_NAMENODE_HEAPSIZE 5120
HADOOP_TASKTRACKER_HEAPSIZE 512
HADOOP_DATANODE_HEAPSIZE 512
mapred.child.java.opts -Xmx1152m
mapred.tasktracker.map.tasks.maximum 12
mapred.tasktracker.reduce.tasks.maximum 3