whbing commented on PR #3960: URL: https://github.com/apache/hadoop/pull/3960#issuecomment-1183957526
Hi, @tomscut , we also face slow nodes caused by io, but in most cases it is slow to read data because the frequency of reading in the cluster far exceeds that of writing. We have counted many cases, when reading slowly, the **iowait** is basically high, but only one or a few disks are full of **ioutil** (12 disks per dn). Therefore, I have the following points to discuss. 1. Is there any further consideration for slow reading? 2. Have you considered reporting iowait to nn, like XmitsInProgress, ActiveTransferThreadCount, etc, so that it is taken into account when choosing a DN? -- 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: common-issues-unsubscr...@hadoop.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
