tomscut opened a new pull request #3288: URL: https://github.com/apache/hadoop/pull/3288
JIRA: [HDFS-16158](https://issues.apache.org/jira/browse/HDFS-16158) Discover datanodes with unbalanced volume usage by the standard deviation In some scenarios, we may cause unbalanced datanode disk usage: 1. Repair the damaged disk and make it online again. 2. Add disks to some Datanodes. 3. Some disks are damaged, resulting in slow data writing. 4. Use some custom volume choosing policies. In the case of unbalanced disk usage, a sudden increase in datanode write traffic may result in busy disk I/O with low volume usage, resulting in decreased throughput across datanodes. In this case, we need to find these nodes in time to do diskBalance, or other processing. Based on the volume usage of each datanode, we can calculate the standard deviation of the volume usage. The more unbalanced the volume, the higher the standard deviation. To prevent the namenode from being too busy, we can calculate the standard variance on the datanode side, transmit it to the namenode through heartbeat, and display the result on the Web of namenode. We can then sort directly to find the nodes on the Web where the volumes usages are unbalanced.  -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
