huaxiangsun commented on a change in pull request #2570: URL: https://github.com/apache/hbase/pull/2570#discussion_r508819430
########## File path: hbase-client/src/main/java/org/apache/hadoop/hbase/client/MetaReplicaLoadBalanceReplicaChooser.java ########## @@ -0,0 +1,53 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.hadoop.hbase.client; + +import org.apache.hadoop.hbase.HRegionLocation; +import org.apache.hadoop.hbase.TableName; +import org.apache.yetus.audience.InterfaceAudience; + +/** + * There are two modes with meta replica support. + * HighAvailable - Client sends requests to the primary meta region first, within a + * configured amount of time, if there is no response coming back, + * client sends requests to all replica regions and takes the first + * response. + * + * LoadBalance - Client sends requests to meta replica regions in a round-robin mode, + * if results from replica regions are stale, next time, client sends requests for + * these stable locations to the primary meta region. In this mode, scan + * requests are load balanced across all replica regions. + */ +enum MetaReplicaMode { + None, + HighAvailable, Review comment: Yeah, META_REPLICAS_MODE_LOADBALANCE_REPILCA_CHOOSER(/SELECTOR) is supposed to be the config change for a different implementation. If it is changed to ReplicaMode, it sounds like this is supported for user tables as well. A ReplicaMode only applies to some special system tables? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
