dragon created HDFS-10028: ----------------------------- Summary: CLONE - Detect if resevered EC Block ID is already used Key: HDFS-10028 URL: https://issues.apache.org/jira/browse/HDFS-10028 Project: Hadoop HDFS Issue Type: Sub-task Components: namenode Reporter: dragon Assignee: Hui Zheng Fix For: HDFS-7285
Since random block IDs were supported by some early version of HDFS, the block ID reserved for EC blocks could be already used by some existing blocks in a cluster. During NameNode startup, it detects if there are reserved EC block IDs used by non-EC blocks. If it is the case, NameNode will do an additional blocksMap lookup when there is a miss in a blockGroupsMap lookup. -- This message was sent by Atlassian JIRA (v6.3.4#6332)