/**
* 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 com.alibaba.wasp.master.handler;
import com.alibaba.wasp.EntityGroupInfo;
import com.alibaba.wasp.Server;
import com.alibaba.wasp.ServerName;
import com.alibaba.wasp.executor.EventHandler;
import com.alibaba.wasp.master.AssignmentManager;
import com.alibaba.wasp.master.EntityGroupState;
import com.alibaba.wasp.zookeeper.ZKAssign;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.zookeeper.KeeperException;
/**
* Handles OPENED entityGroup event on FMaster.
*/
public class OpenedEntityGroupHandler extends EventHandler {
private static final Log LOG = LogFactory
.getLog(OpenedEntityGroupHandler.class);
private final AssignmentManager assignmentManager;
private final EntityGroupInfo entityGroupInfo;
private final ServerName sn;
private final int expectedVersion;
public OpenedEntityGroupHandler(Server server,
AssignmentManager assignmentManager, EntityGroupInfo entityGroupInfo,
ServerName sn, int expectedVersion) {
super(server, EventType.FSERVER_ZK_ENTITYGROUP_OPENED);
this.assignmentManager = assignmentManager;
this.entityGroupInfo = entityGroupInfo;
this.sn = sn;
this.expectedVersion = expectedVersion;
}
@Override
public void process() {
// Code to defend against case where we get SPLIT before EntityGroup open
// processing completes; temporary till we make SPLITs go via zk -- 0.92.
EntityGroupState entityGroupState = this.assignmentManager
.getEntityGroupStates().getEntityGroupTransitionState(
entityGroupInfo.getEncodedName());
boolean openedNodeDeleted = false;
if (entityGroupState != null && entityGroupState.isOpened()) {
openedNodeDeleted = deleteOpenedNode(expectedVersion);
if (!openedNodeDeleted) {
LOG.error("The znode of entityGroup "
+ entityGroupInfo.getEntityGroupNameAsString()
+ " could not be deleted.");
}
} else {
LOG.warn("Skipping the onlining of "
+ entityGroupInfo.getEntityGroupNameAsString()
+ " because entityGroups is NOT in EGIT -- presuming this is because it SPLIT");
}
if (!openedNodeDeleted) {
if (this.assignmentManager.getZKTable().isDisablingOrDisabledTable(
entityGroupInfo.getTableNameAsString())) {
debugLog(entityGroupInfo,
"Opened EntityGroup "
+ entityGroupInfo.getEntityGroupNameAsString()
+ " but this table is disabled, triggering close of EntityGroup");
assignmentManager.unassign(entityGroupInfo);
}
}
}
private boolean deleteOpenedNode(int expectedVersion) {
debugLog(entityGroupInfo, "Handling OPENED event for "
+ this.entityGroupInfo.getEntityGroupNameAsString()
+ " from " + this.sn.toString() + "; deleting unassigned node");
try {
// delete the opened znode only if the version matches.
return ZKAssign.deleteNode(server.getZooKeeper(),
entityGroupInfo.getEncodedName(),
EventType.FSERVER_ZK_ENTITYGROUP_OPENED,
expectedVersion);
} catch (KeeperException.NoNodeException e) {
// Getting no node exception here means that already the entityGroup has been
// opened.
LOG.warn("The znode of the entityGroup "
+ entityGroupInfo.getEntityGroupNameAsString()
+ " would have already been deleted");
return false;
} catch (KeeperException e) {
server.abort(
"Error deleting OPENED node in ZK ("
+ entityGroupInfo.getEntityGroupNameAsString() + ")", e);
}
return false;
}
private void debugLog(EntityGroupInfo entityGroupInfo, String string) {
LOG.debug(string);
}
@Override
public String toString() {
String name = "UnknownServerName";
if (server != null && server.getServerName() != null) {
name = server.getServerName().toString();
}
return getClass().getSimpleName() + "-" + name + "-" + getSeqid();
}
}