org.apache.hadoop.hbase.CatalogReplicaMode Maven / Gradle / Ivy
/*
* 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;
import org.apache.yetus.audience.InterfaceAudience;
/**
*
* There are two modes with catalog replica support.
*
*
* - HEDGED_READ - Client sends requests to the primary 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.
* - LOAD_BALANCE - Client sends requests to replica regions in a round-robin mode, if results
* from replica regions are stale, next time, client sends requests for these stale locations to the
* primary region. In this mode, scan requests are load balanced across all replica regions.
*
*/
@InterfaceAudience.Private
public enum CatalogReplicaMode {
NONE {
@Override
public String toString() {
return "None";
}
},
HEDGED_READ {
@Override
public String toString() {
return "HedgedRead";
}
},
LOAD_BALANCE {
@Override
public String toString() {
return "LoadBalance";
}
};
public static CatalogReplicaMode fromString(final String value) {
for (CatalogReplicaMode mode : values()) {
if (mode.toString().equalsIgnoreCase(value)) {
return mode;
}
}
throw new IllegalArgumentException();
}
}