[HDFS-7842] Blocks missed while performing downgrade immediately after rolling back the cluster.

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Duplicate
• Component/s: datanode
• Assignee: J.Andreina
• Reporter: J.Andreina
• Created: 25/Feb/15 09:40
• Updated: 14/Apr/15 06:46
• Resolved: 14/Apr/15 06:46

Description

Performing downgrade immediately after rolling back the cluster , will replace the blocks from trash

Since the block id for the files created before rollback will be same as the file created before downgrade, namenode will get into safemode , as the block size reported from Datanode will be different from the one in block map (corrupted blocks) .

Steps to Reproduce

Step 1: Prepare rolling upgrade using "hdfs dfsadmin -rollingUpgrade prepare"
Step 2: Shutdown SNN and NN
Step 3: Start NN with the "hdfs namenode -rollingUpgrade started" option.
Step 4: Executed "hdfs dfsadmin -shutdownDatanode <DATANODE_HOST:IPC_PORT> upgrade" and restarted Datanode
Step 5: Create File_1 of size 11526
Step 6: Shutdown both NN and DN
Step 7: Start NNs with the "hdfs namenode -rollingUpgrade rollback" option.
	Start DNs with the "-rollback" option.
Step 8: Prepare rolling upgrade using "hdfs dfsadmin -rollingUpgrade prepare"
Step 9: Shutdown SNN and NN
Step 10: Start NN with the "hdfs namenode -rollingUpgrade started" option .
Step 11: Executed "hdfs dfsadmin -shutdownDatanode <DATANODE_HOST:IPC_PORT> upgrade" and restarted Datanode
step 12: Add file File_2 with size 6324 (which has same blockid as previous created File_1 with block size 11526)
Step 13: Shutdown both NN and DN
Step 14: Start NNs with the "hdfs namenode -rollingUpgrade downgrade" option.Start DNs normally.

Issue Links

• is related to: HDFS-7302 namenode -rollingUpgrade downgrade may finalize a rolling upgrade
• is related to: HDFS-7645 Rolling upgrade is restoring blocks from trash multiple times