[HBASE-21492] CellCodec Written To WAL Before It's Verified

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.2.7, 2.0.2
• Fix Version/s: 3.0.0-alpha-1, 2.2.0, 2.1.2, 1.2.10, 2.0.4, 1.4.10, 1.3.4
• Component/s: wal
• Hadoop Flags: Incompatible change, Reviewed

Release Note

After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class

• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 16/Nov/18 21:33
• Updated: 07/Oct/19 18:24
• Resolved: 27/Nov/18 16:59

Description

The cell codec class name is written into the WAL file, but the cell codec class is not actually verified to exist. Therefore, users can inadvertently configure an invalid class name and it will be recorded into the WAL file. At that point, the WAL file becomes unreadable and blocks processing of all other WAL files.

AbstractProtobufLogWriter.java

  private WALHeader buildWALHeader0(Configuration conf, WALHeader.Builder builder) {
    if (!builder.hasWriterClsName()) {
      builder.setWriterClsName(getWriterClassName());
    }
    if (!builder.hasCellCodecClsName()) {
      builder.setCellCodecClsName(WALCellCodec.getWALCellCodecClass(conf));
    }
    return builder.build();
  }

https://github.com/apache/hbase/blob/025ddce868eb06b4072b5152c5ffae5a01e7ae30/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/AbstractProtobufLogWriter.java#L78-L86