[ https://issues.apache.org/jira/browse/HDFS-17150?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17754409#comment-17754409 ]
ASF GitHub Bot commented on HDFS-17150: --------------------------------------- hfutatzhanghb commented on PR #5937: URL: https://github.com/apache/hadoop/pull/5937#issuecomment-1678450434 LGTM. +1. > EC: Fix the bug of failed lease recovery. > ----------------------------------------- > > Key: HDFS-17150 > URL: https://issues.apache.org/jira/browse/HDFS-17150 > Project: Hadoop HDFS > Issue Type: Bug > Reporter: Shuyan Zhang > Priority: Major > Labels: pull-request-available > > If the client crashes without writing the minimum number of internal blocks > required by the EC policy, the lease recovery process for the corresponding > unclosed file may continue to fail. Taking RS(6,3) policy as an example, the > timeline is as follows: > 1. The client writes some data to only 5 datanodes; > 2. Client crashes; > 3. NN fails over; > 4. Now the result of `uc.getNumExpectedLocations()` completely depends on > block report, and there are 5 datanodes reporting internal blocks; > 5. When the lease expires hard limit, NN issues a block recovery command; > 6. The datanode checks the command and finds that the number of internal > blocks is insufficient, resulting in an error and recovery failure; > 7. The lease expires hard limit again, and NN issues a block recovery command > again, but the recovery fails again...... > When the number of internal blocks written by the client is less than 6, the > block group is actually unrecoverable. We should equate this situation to the > case where the number of replicas is 0 when processing replica files, i.e., > directly remove the last block group and close the file. > -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org