private void closeRegionSilently(ServerName sn, byte[] regionName) {
    try {
      RegionInfo ri = CatalogFamilyFormat.parseRegionInfoFromRegionName(regionName);
      // Pass -1 for timeout. Means do not wait.
      ServerManager.closeRegionSilentlyAndWait(this.master.getAsyncClusterConnection(), sn, ri, -1);
    } catch (Exception e) {
      LOG.error("Failed trying to close {} on {}", Bytes.toStringBinary(regionName), sn, e);
    }
  }
Close <code>regionName</code> on <code>sn</code> silently and immediately without using a
Procedure or going via hbase:meta. For case where a RegionServer's hosting of a Region is not
aligned w/ the Master's accounting of Region state. This is for cleaning up an error in
accounting.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java