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Hadoop QA commented on HDFS-5153: --------------------------------- {color:green}+1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12625769/HDFS-5153.05.patch against trunk revision . {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 4 new or modified test files. {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:green}+1 javadoc{color}. The javadoc tool did not generate any warning messages. {color:green}+1 eclipse:eclipse{color}. The patch built with eclipse:eclipse. {color:green}+1 findbugs{color}. The patch does not introduce any new Findbugs (version 1.3.9) warnings. {color:green}+1 release audit{color}. The applied patch does not increase the total number of release audit warnings. {color:green}+1 core tests{color}. The patch passed unit tests in hadoop-hdfs-project/hadoop-hdfs. {color:green}+1 contrib tests{color}. The patch passed contrib unit tests. Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/5971//testReport/ Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/5971//console This message is automatically generated. > Datanode should send block reports for each storage in a separate message > ------------------------------------------------------------------------- > > Key: HDFS-5153 > URL: https://issues.apache.org/jira/browse/HDFS-5153 > Project: Hadoop HDFS > Issue Type: Bug > Components: datanode > Affects Versions: 3.0.0 > Reporter: Arpit Agarwal > Assignee: Arpit Agarwal > Attachments: HDFS-5153.01.patch, HDFS-5153.03.patch, > HDFS-5153.03b.patch, HDFS-5153.04.patch, HDFS-5153.05.patch > > > When the number of blocks on the DataNode grows large we start running into a > few issues: > # Block reports take a long time to process on the NameNode. In testing we > have seen that a block report with 6 Million blocks takes close to one second > to process on the NameNode. The NameSystem write lock is held during this > time. > # We start hitting the default protobuf message limit of 64MB somewhere > around 10 Million blocks. While we can increase the message size limit it > already takes over 7 seconds to serialize/unserialize a block report of this > size. > HDFS-2832 has introduced the concept of a DataNode as a collection of > storages i.e. the NameNode is aware of all the volumes (storage directories) > attached to a given DataNode. This makes it easy to split block reports from > the DN by sending one report per storage directory to mitigate the above > problems. -- This message was sent by Atlassian JIRA (v6.1.5#6160)