private static void printHelp() {
    System.err.println("usage: Compressor <input> <output>");
    System.err.println("If <input> WAL is compressed, <output> will be decompressed.");
    System.err.println("If <input> WAL is uncompressed, <output> will be compressed.");
    return;
  }
Command line tool to compress and uncompress WALs.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/Compressor.java