[HDFS-11112] Journal Nodes should refuse to format non-empty directories

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha4
• Target Version/s: 2.9.0
• Hadoop Flags: Reviewed
• Assignee: Yiqun Lin
• Reporter: Arpit Agarwal
• Created: 05/Nov/16 16:58
• Updated: 02/Oct/19 17:15
• Resolved: 02/Feb/17 01:03

Description

Journal Nodes should reject the format RPC request if a storage directory is non-empty. The relevant code is in JNStorage#format.

  void format(NamespaceInfo nsInfo) throws IOException {
    setStorageInfo(nsInfo);
...
    unlockAll();
    sd.clearDirectory();
    writeProperties(sd);
    createPaxosDir();
    analyzeStorage();

This would make the behavior similar to namenode -format -nonInteractive.

Issue Links

• is related to: HDFS-10360 DataNode may format directory and lose blocks if current/VERSION is missing
• is related to: HDFS-10457 DataNode should not auto-format block pool directory if VERSION is missing
• relates to: HDFS-13805 Journal Nodes should allow to format non-empty directories with "-force" option