001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.apache.hadoop.hbase.client; 019 020import java.io.Closeable; 021import java.util.concurrent.CompletableFuture; 022import org.apache.hadoop.hbase.RegionLocations; 023import org.apache.hadoop.hbase.ServerName; 024import org.apache.yetus.audience.InterfaceAudience; 025 026/** 027 * Registry for meta information needed for connection setup to a HBase cluster. Implementations 028 * hold cluster information such as this cluster's id, location of hbase:meta, etc.. Internal use 029 * only. 030 */ 031@InterfaceAudience.Private 032public interface ConnectionRegistry extends Closeable { 033 034 /** 035 * Get the location of meta region(s). 036 */ 037 CompletableFuture<RegionLocations> getMetaRegionLocations(); 038 039 /** 040 * Should only be called once. 041 * <p> 042 * The upper layer should store this value somewhere as it will not be change any more. 043 */ 044 CompletableFuture<String> getClusterId(); 045 046 /** 047 * Get the address of active HMaster. 048 */ 049 CompletableFuture<ServerName> getActiveMaster(); 050 051 /** 052 * Return the connection string associated with this registry instance. This value is 053 * informational, used for annotating traces. Values returned may not be valid for establishing a 054 * working cluster connection. 055 */ 056 String getConnectionString(); 057 058 /** 059 * Closes this instance and releases any system resources associated with it 060 */ 061 @Override 062 void close(); 063}