/**
*
* 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.master.handler;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.AssignmentManager;
import org.apache.hadoop.hbase.master.RegionState;
import org.apache.hadoop.hbase.zookeeper.ZKAssign;
import org.apache.zookeeper.KeeperException;
/**
* Handles OPENED region event on Master.
*/
@InterfaceAudience.Private
public class OpenedRegionHandler extends EventHandler implements TotesHRegionInfo {
private static final Log LOG = LogFactory.getLog(OpenedRegionHandler.class);
private final AssignmentManager assignmentManager;
private final HRegionInfo regionInfo;
private final ServerName sn;
private final OpenedPriority priority;
private final int expectedVersion;
private enum OpenedPriority {
META (1),
USER (2);
private final int value;
OpenedPriority(int value) {
this.value = value;
}
public int getValue() {
return value;
}
};
public OpenedRegionHandler(Server server,
AssignmentManager assignmentManager, HRegionInfo regionInfo,
ServerName sn, int expectedVersion) {
super(server, EventType.RS_ZK_REGION_OPENED);
this.assignmentManager = assignmentManager;
this.regionInfo = regionInfo;
this.sn = sn;
this.expectedVersion = expectedVersion;
if(regionInfo.isMetaRegion()) {
priority = OpenedPriority.META;
} else {
priority = OpenedPriority.USER;
}
}
@Override
public int getPriority() {
return priority.getValue();
}
@Override
public HRegionInfo getHRegionInfo() {
return this.regionInfo;
}
@Override
public String toString() {
String name = "UnknownServerName";
if(server != null && server.getServerName() != null) {
name = server.getServerName().toString();
}
return getClass().getSimpleName() + "-" + name + "-" + getSeqid();
}
@Override
public void process() {
// Code to defend against case where we get SPLIT before region open
// processing completes; temporary till we make SPLITs go via zk -- 0.92.
RegionState regionState = this.assignmentManager.getRegionStates()
.getRegionTransitionState(regionInfo.getEncodedName());
boolean openedNodeDeleted = false;
if (regionState != null && regionState.isOpened()) {
openedNodeDeleted = deleteOpenedNode(expectedVersion);
if (!openedNodeDeleted) {
LOG.error("The znode of region " + regionInfo.getRegionNameAsString()
+ " could not be deleted.");
}
} else {
LOG.warn("Skipping the onlining of " + regionInfo.getRegionNameAsString() +
" because regions is NOT in RIT -- presuming this is because it SPLIT");
}
if (!openedNodeDeleted) {
if (this.assignmentManager.getZKTable().isDisablingOrDisabledTable(
regionInfo.getTableNameAsString())) {
debugLog(regionInfo, "Opened region "
+ regionInfo.getRegionNameAsString() + " but "
+ "this table is disabled, triggering close of region");
assignmentManager.unassign(regionInfo);
}
}
}
private boolean deleteOpenedNode(int expectedVersion) {
debugLog(regionInfo, "Handling OPENED event for " +
this.regionInfo.getRegionNameAsString() + " from " + this.sn.toString() +
"; deleting unassigned node");
try {
// delete the opened znode only if the version matches.
return ZKAssign.deleteNode(server.getZooKeeper(),
regionInfo.getEncodedName(), EventType.RS_ZK_REGION_OPENED, expectedVersion);
} catch(KeeperException.NoNodeException e){
// Getting no node exception here means that already the region has been opened.
LOG.warn("The znode of the region " + regionInfo.getRegionNameAsString() +
" would have already been deleted");
return false;
} catch (KeeperException e) {
server.abort("Error deleting OPENED node in ZK (" +
regionInfo.getRegionNameAsString() + ")", e);
}
return false;
}
private void debugLog(HRegionInfo region, String string) {
if (region.isMetaTable()) {
LOG.info(string);
} else {
LOG.debug(string);
}
}
}