Surendra Singh Lilhore created HDFS-9023: --------------------------------------------
Summary: When NN is not able to identify DN for replication, reason behind it can be logged Key: HDFS-9023 URL: https://issues.apache.org/jira/browse/HDFS-9023 Project: Hadoop HDFS Issue Type: Improvement Components: hdfs-client, namenode Affects Versions: 2.7.1 Reporter: Surendra Singh Lilhore Assignee: Surendra Singh Lilhore Priority: Critical When NN is not able to identify DN for replication, reason behind it can be logged (at least critical information why DNs not chosen like disk is full). At present it is expected to enable debug log. For example the reason for below error looks like all 7 DNs are busy for data writes. But at client or NN side no hint is given in the log message. {noformat} File /tmp/logs/spark/logs/application_1437051383180_0610/xyz-195_26009.tmp could only be replicated to 0 nodes instead of minReplication (=1). There are 7 datanode(s) running and no node(s) are excluded in this operation. at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1553) {noformat} -- This message was sent by Atlassian JIRA (v6.3.4#6332)