private ScheduledChore
    getRefreshReplicaCountChore(final CatalogReplicaLoadBalanceSimpleSelector selector) {
    return new ScheduledChore("RefreshReplicaCountChore", this,
      REFRESH_REPLICA_COUNT_CHORE_INTERVAL_IN_MILLISECONDS) {
      @Override
      protected void chore() {
        selector.refreshCatalogReplicaCount();
      }
    };
  }
When it looks up a location, it will call this method to find a replica region to go. For a
normal case, > 99% of region locations from catalog/meta replica will be up to date. In extreme
cases such as region server crashes, it will depends on how fast replication catches up.
@param tableName  table name it looks up
@param row        key it looks up.
@param locateType locateType, Only BEFORE and CURRENT will be passed in.
@return catalog replica id
hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java