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/*-
* Copyright (C) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle Berkeley
* DB Java Edition made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle Berkeley DB Java Edition for a copy of the
* license and additional information.
*/
package com.sleepycat.je.rep.impl;
import static com.sleepycat.je.rep.impl.RepParams.GROUP_NAME;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.channels.Channels;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.logging.Logger;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.dbi.DbConfigManager;
import com.sleepycat.je.rep.MasterStateException;
import com.sleepycat.je.rep.MasterTransferFailureException;
import com.sleepycat.je.rep.MemberActiveException;
import com.sleepycat.je.rep.MemberNotFoundException;
import com.sleepycat.je.rep.ReplicaStateException;
import com.sleepycat.je.rep.impl.RepGroupImpl;
import com.sleepycat.je.rep.impl.RepGroupProtocol.DeleteMember;
import com.sleepycat.je.rep.impl.RepGroupProtocol.EnsureNode;
import com.sleepycat.je.rep.impl.RepGroupProtocol.FailReason;
import com.sleepycat.je.rep.impl.RepGroupProtocol.GroupRequest;
import com.sleepycat.je.rep.impl.RepGroupProtocol.RemoveMember;
import com.sleepycat.je.rep.impl.RepGroupProtocol.TransferMaster;
import com.sleepycat.je.rep.impl.RepGroupProtocol.UpdateAddress;
import com.sleepycat.je.rep.impl.TextProtocol.RequestMessage;
import com.sleepycat.je.rep.impl.TextProtocol.ResponseMessage;
import com.sleepycat.je.rep.impl.node.RepNode;
import com.sleepycat.je.rep.net.DataChannel;
import com.sleepycat.je.rep.utilint.ServiceDispatcher;
import com.sleepycat.je.rep.utilint.ServiceDispatcher.ExecutingService;
import com.sleepycat.je.rep.utilint.ServiceDispatcher.ExecutingRunnable;
import com.sleepycat.je.utilint.LoggerUtils;
public class GroupService extends ExecutingService {
/* The replication node */
final RepNode repNode;
final RepGroupProtocol protocol;
/**
* List of channels for in-flight requests.
* The channel is in this collection while the request is being processed,
* and must be removed before sending any response.
*
* @see #cancel
* @see #unregisterChannel
*/
private final Collection activeChannels =
new ArrayList();
private final Logger logger;
/* Identifies the Group Service. */
public static final String SERVICE_NAME = "Group";
public GroupService(ServiceDispatcher dispatcher, RepNode repNode) {
super(SERVICE_NAME, dispatcher);
this.repNode = repNode;
final DbConfigManager configManager =
repNode.getRepImpl().getConfigManager();
String groupName = configManager.get(GROUP_NAME);
protocol =
new RepGroupProtocol(groupName,
repNode.getNameIdPair(),
repNode.getRepImpl(),
repNode.getRepImpl().getChannelFactory());
logger = LoggerUtils.getLogger(getClass());
}
@Override
protected void cancel() {
Collection channels;
synchronized (this) {
channels = new ArrayList(activeChannels);
activeChannels.clear();
}
if (!channels.isEmpty()) {
LoggerUtils.warning
(logger, repNode.getRepImpl(),
"In-flight GroupService request(s) canceled: node shutdown");
}
for (DataChannel channel : channels) {
try {
PrintWriter out =
new PrintWriter(Channels.newOutputStream(channel), true);
ResponseMessage rm =
protocol.new Fail(FailReason.DEFAULT, "shutting down");
out.println(rm.wireFormat());
} finally {
if (channel.isOpen()) {
try {
channel.close();
}
catch (IOException e) {
LoggerUtils.warning
(logger, repNode.getRepImpl(),
"IO error on channel close: " + e.getMessage());
}
}
}
}
}
/* Dynamically invoked process methods */
/**
* Wraps the replication group as currently cached on this node in
* a Response message and returns it.
*/
@SuppressWarnings("unused")
public ResponseMessage process(GroupRequest groupRequest) {
RepGroupImpl group = repNode.getGroup();
if (group == null) {
return protocol.new Fail(groupRequest, FailReason.DEFAULT,
"no group info yet");
}
return protocol.new GroupResponse(groupRequest, group);
}
/**
* Ensures that the Monitor node, as described in the request, is a member
* of the group.
*
* @param ensureNode the request message describing the monitor node
*
* @return EnsureOK message if the monitor node is already part of the rep
* group, or was just made a part of the replication group. It returns a
* Fail message if it could not be made part of the group. The message
* associated with the response provides further details.
*/
public ResponseMessage process(EnsureNode ensureNode) {
RepNodeImpl node = ensureNode.getNode();
try {
ensureMaster();
repNode.getRepGroupDB().ensureMember(node);
RepNodeImpl enode =
repNode.getGroup().getMember(node.getName());
return protocol.new EnsureOK(ensureNode, enode.getNameIdPair());
} catch (ReplicaStateException e) {
return protocol.new Fail(ensureNode, FailReason.IS_REPLICA,
e.getMessage());
} catch (DatabaseException e) {
return protocol.new Fail(ensureNode, FailReason.DEFAULT,
e.getMessage());
}
}
/**
* Removes a current member from the group.
*
* @param removeMember the request identifying the member to be removed.
*
* @return OK message if the member was removed from the group.
*/
public ResponseMessage process(RemoveMember removeMember) {
final String nodeName = removeMember.getNodeName();
try {
ensureMaster();
repNode.removeMember(nodeName);
return protocol.new OK(removeMember);
} catch (MemberNotFoundException e) {
return protocol.new Fail(removeMember, FailReason.MEMBER_NOT_FOUND,
e.getMessage());
} catch (MasterStateException e) {
return protocol.new Fail(removeMember, FailReason.IS_MASTER,
e.getMessage());
} catch (ReplicaStateException e) {
return protocol.new Fail(removeMember, FailReason.IS_REPLICA,
e.getMessage());
} catch (DatabaseException e) {
return protocol.new Fail(removeMember, FailReason.DEFAULT,
e.getMessage());
}
}
/**
* Deletes a current member from the group, which marks the node as removed
* and deletes its entry from the rep group DB.
*
* @param deleteMember the request identifying the member to be deleted
*
* @return OK message if the member was deleted from the group
*/
public ResponseMessage process(DeleteMember deleteMember) {
final String nodeName = deleteMember.getNodeName();
try {
ensureMaster();
repNode.removeMember(nodeName, true);
return protocol.new OK(deleteMember);
} catch (MemberNotFoundException e) {
return protocol.new Fail(deleteMember, FailReason.MEMBER_NOT_FOUND,
e.getMessage());
} catch (MasterStateException e) {
return protocol.new Fail(deleteMember, FailReason.IS_MASTER,
e.getMessage());
} catch (ReplicaStateException e) {
return protocol.new Fail(deleteMember, FailReason.IS_REPLICA,
e.getMessage());
} catch (MemberActiveException e) {
return protocol.new Fail(deleteMember, FailReason.MEMBER_ACTIVE,
e.getMessage());
} catch (DatabaseException e) {
return protocol.new Fail(deleteMember, FailReason.DEFAULT,
e.getMessage());
}
}
/**
* Update the network address for a dead replica.
*
* @param updateAddress the request identifying the new network address for
* the node.
*
* @return OK message if the address is successfully updated.
*/
public ResponseMessage process(UpdateAddress updateAddress) {
try {
ensureMaster();
repNode.updateAddress(updateAddress.getNodeName(),
updateAddress.getNewHostName(),
updateAddress.getNewPort());
return protocol.new OK(updateAddress);
} catch (MemberNotFoundException e) {
return protocol.new Fail(
updateAddress, FailReason.MEMBER_NOT_FOUND, e.getMessage());
} catch (MasterStateException e) {
return protocol.new Fail(updateAddress, FailReason.IS_MASTER,
e.getMessage());
} catch (ReplicaStateException e) {
return protocol.new Fail(updateAddress, FailReason.IS_REPLICA,
e.getMessage());
} catch (DatabaseException e) {
return protocol.new Fail(updateAddress, FailReason.DEFAULT,
e.getMessage());
}
}
/**
* Transfer the master role from the current master to one of the specified
* replicas.
*
* @param transferMaster the request identifying nodes to be considered for
* the role of new master
* @return null
*/
public ResponseMessage process(TransferMaster transferMaster) {
try {
ensureMaster();
final String nodeList = transferMaster.getNodeNameList();
final Set replicas = parseNodeList(nodeList);
final long timeout = transferMaster.getTimeout();
final boolean force = transferMaster.getForceFlag();
String winner = repNode.transferMaster(replicas, timeout, force);
return protocol.new TransferOK(transferMaster, winner);
} catch (ReplicaStateException e) {
return protocol.new Fail(transferMaster, FailReason.IS_REPLICA,
e.getMessage());
} catch (MasterTransferFailureException e) {
return protocol.new Fail(transferMaster, FailReason.TRANSFER_FAIL,
e.getMessage());
} catch (DatabaseException e) {
return protocol.new Fail(transferMaster, FailReason.DEFAULT,
e.getMessage());
} catch (IllegalArgumentException e) {
return protocol.new Fail(transferMaster, FailReason.DEFAULT,
e.toString());
} catch (IllegalStateException e) {
return protocol.new Fail(transferMaster, FailReason.DEFAULT,
e.toString());
}
}
private Set parseNodeList(String list) {
Set set = new HashSet();
StringTokenizer st = new StringTokenizer(list, ",");
while (st.hasMoreTokens()) {
set.add(st.nextToken());
}
return set;
}
private void ensureMaster() throws ReplicaStateException {
if (!repNode.isMaster()) {
throw new ReplicaStateException
("GroupService operation can only be performed at master");
}
}
synchronized private void registerChannel(DataChannel dc) {
activeChannels.add(dc);
}
/**
* Removes the given {@code DataChannel} from our list of active channels.
*
* Before sending any response on the channel, this method must be invoked
* to claim ownership of it.
* This avoids a potential race between the request processing thread in
* the normal case, and a thread calling {@code cancel()} at env shutdown
* time.
*
* @return true, if the channel is still active (usual case); false
* otherwise, presumably because the service was shut down.
*/
synchronized private boolean unregisterChannel(DataChannel dc) {
return activeChannels.remove(dc);
}
@Override
public Runnable getRunnable(DataChannel dataChannel) {
return new GroupServiceRunnable(dataChannel, protocol);
}
class GroupServiceRunnable extends ExecutingRunnable {
GroupServiceRunnable(DataChannel dataChannel,
RepGroupProtocol protocol) {
super(dataChannel, protocol, true);
registerChannel(dataChannel);
}
@Override
protected ResponseMessage getResponse(RequestMessage request)
throws IOException {
ResponseMessage rm = protocol.process(GroupService.this, request);
/*
* If the channel has already been closed, before we got a chance to
* produce the response, then just discard the tardy response and
* return null.
*/
return unregisterChannel(channel) ? rm : null;
}
@Override
protected void logMessage(String message) {
LoggerUtils.warning(logger, repNode.getRepImpl(), message);
}
}
}
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