@Deprecated
  public static long getMaxRegionSequenceId(Configuration conf, RegionInfo region,
    IOExceptionSupplier<FileSystem> rootFsSupplier, IOExceptionSupplier<FileSystem> walFsSupplier)
    throws IOException {
    FileSystem rootFs = rootFsSupplier.get();
    FileSystem walFs = walFsSupplier.get();
    Path regionWALDir =
      CommonFSUtils.getWALRegionDir(conf, region.getTable(), region.getEncodedName());
    // This is the old place where we store max sequence id file
    Path regionDir = FSUtils.getRegionDirFromRootDir(CommonFSUtils.getRootDir(conf), region);
    // This is for HBASE-20734, where we use a wrong directory, see HBASE-22617 for more details.
    Path wrongRegionWALDir =
      CommonFSUtils.getWrongWALRegionDir(conf, region.getTable(), region.getEncodedName());
    long maxSeqId = getMaxRegionSequenceId(walFs, regionWALDir);
    maxSeqId = Math.max(maxSeqId, getMaxRegionSequenceId(rootFs, regionDir));
    maxSeqId = Math.max(maxSeqId, getMaxRegionSequenceId(walFs, wrongRegionWALDir));
    return maxSeqId;
  }
This method will check 3 places for finding the max sequence id file. One is the expected
place, another is the old place under the region directory, and the last one is the wrong one
we introduced in HBASE-20734. See HBASE-22617 for more details.
<p/>
Notice that, you should always call this method instead of
{@link #getMaxRegionSequenceId(FileSystem, Path)} until 4.0.0 release.
@deprecated Only for compatibility, will be removed in 4.0.0.
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALSplitUtil.java