public static String getWALPrefixFromWALName(String name) {
    return getWALNameGroupFromWALName(name, 1);
  }
Get prefix of the log from its name, assuming WAL name in format of
log_prefix.filenumber.log_suffix
@param name Name of the WAL to parse
@return prefix of the log
@throws IllegalArgumentException if the name passed in is not a valid wal file name
@see AbstractFSWAL#getCurrentFileName()
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/AbstractFSWALProvider.java