Jing Zhao created HDFS-5590: ------------------------------- Summary: Sequential block ID may cause data loss when persistBlocks is set to false Key: HDFS-5590 URL: https://issues.apache.org/jira/browse/HDFS-5590 Project: Hadoop HDFS Issue Type: Bug Affects Versions: 2.2.0 Reporter: Jing Zhao Assignee: Jing Zhao
In a cluster with non-HA setup and dfs.persist.blocks set to false, the current sequential block ID may cause data loss in the following case: # client creates file1 and requests a block from NN and get blk_id1_gs1 # client writes blk_id1_gs1 to DN # NN is restarted and because persistBlocks is false, blk_id1_gs1 is not persisted in editlog # another client creates file2 and NN will allocate a new block using the same block id blk_id1_gs1 since block ID and generation stamp are both increased sequentially. Now we may have two versions (file1 and file2) of the blk_id1_gs1 (same id, same gs) in the system. It will case data loss. -- This message was sent by Atlassian JIRA (v6.1#6144)