huangzhaobo99 commented on PR #6505: URL: https://github.com/apache/hadoop/pull/6505#issuecomment-1919480906
> @huangzhaobo99 I have a question. If the IO of the machine where the DN is located is abnormal, causing exceptions in many blocks, what will this metric look like? > > https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-6505/7/artifact/out/branch-mvninstall-root.txt > > We should fix mvn install, we need to re-trigger compilation. Hi @slfan1989, Is the IO exception mentioned here a fault with DN? If so, There are currently relevant exception handling mechanisms in place, there is to ensure that the elements stored in the map set are reasonable, including the following points: 1. The readBlock method adds 1 to the blockId before reading data, and subtracts 1 from the blockId when it executes normally or throws an exception. 2. The maximum number of read threads on a DN is close to the configuration of the xciver thread. When there is an exception in the read block, the total value in the map will not exceed the number of resident xciver threads. 3. When there is no read request, this map is an empty set of maps. In addition, the ReadBlockIdCounts metric and the xciver thread metric are used together, when a sudden increase in xciver threads is detected and lasts for 2 or 3 minutes, the map can be used to locate the block that has been abnormally accessed. -- 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]
