private void setupSignalHandlers() {
    if (!SystemUtils.IS_OS_WINDOWS) {
      HBasePlatformDependent.handle("HUP", (number, name) -> {
        try {
          updateConfiguration();
        } catch (IOException e) {
          LOG.error("Problem while reloading configuration", e);
        }
      });
    }
  }
Cache for the meta region replica's locations. Also tracks their changes to avoid stale cache
entries. Used for serving ClientMetaService.
hbase-server/src/main/java/org/apache/hadoop/hbase/HBaseServerBase.java