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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/53248/
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(Updated Oct. 27, 2016, 11:20 p.m.)


Review request for Ambari and Jaimin Jetly.


Repository: ambari


Description
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As HDFS-11047 reported, DirectoryScanner does scan by deep copying 
FinalizedReplica. In a deployment with 500,000+ blocks, we've seen the DN heap 
usage being accumulated to high peaks very quickly. Deep copies of 
FinalizedReplica will make DN heap usage even worse if directory scans are 
scheduled more frequently. 

Another factor is that huge number of ScanInfo instances corresponding to HDFS 
blocks are lingering in garbage to eat many heap memories until a full GC takes 
place.

This proposes adding JVM settings to force GC more frequently to release 
DataNode heap consumed as a result of two aforementioned reasons, i.e. add the 
options to HADOOP_DATANODE_OPTS
{noformat}
-XX:CMSInitiatingOccupancyFraction=70 -XX:+UseCMSInitiatingOccupancyOnly 
-XX:ConcGCThreads=8 -XX:+UseConcMarkSweepGC
{noformat}


Diffs
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ambari-funtest/src/test/resources/stacks/HDP/0.2/services/HDFS/configuration/hadoop-env.xml
 2f88e06 
  
ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/configuration/hadoop-env.xml
 32442d9 
  
ambari-server/src/main/resources/stacks/BIGTOP/0.8/services/HDFS/configuration/hadoop-env.xml
 5188913 
  
ambari-server/src/main/resources/stacks/HDP/2.0.6.GlusterFS/services/GLUSTERFS/configuration/hadoop-env.xml
 5c1c441 
  
ambari-server/src/main/resources/stacks/HDP/2.1.GlusterFS/services/GLUSTERFS/configuration/hadoop-env.xml
 95fc12a 
  
ambari-server/src/main/resources/stacks/HDP/2.2/services/HDFS/configuration/hadoop-env.xml
 7b92a6c 
  
ambari-server/src/main/resources/stacks/HDP/2.3.GlusterFS/services/GLUSTERFS/configuration/hadoop-env.xml
 f005a75 
  
ambari-server/src/main/resources/stacks/HDPWIN/2.1/services/HDFS/configuration/hadoop-env.xml
 0371194 
  
ambari-server/src/main/resources/stacks/HDPWIN/2.2/services/HDFS/configuration/hadoop-env.xml
 08a1847 
  
ambari-server/src/test/resources/stacks/HDP/0.2/services/HDFS/configuration/hadoop-env.xml
 228b2e0 
  
ambari-server/src/test/resources/stacks_with_common_services/HDP/0.2/services/HDFS/configuration/hadoop-env.xml
 b8b5f8c 
  
ambari-server/src/test/resources/stacks_with_extensions/HDP/0.2/services/HDFS/configuration/hadoop-env.xml
 2f9b95f 

Diff: https://reviews.apache.org/r/53248/diff/


Testing
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Thanks,

XIAOBING ZHOU

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