// 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.cloud.agent.manager;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import javax.ejb.Local;
import javax.naming.ConfigurationException;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import org.apache.log4j.Logger;
import com.cloud.agent.AgentManager;
import com.cloud.agent.api.Answer;
import com.cloud.agent.api.CancelCommand;
import com.cloud.agent.api.ChangeAgentCommand;
import com.cloud.agent.api.Command;
import com.cloud.agent.api.TransferAgentCommand;
import com.cloud.agent.transport.Request;
import com.cloud.agent.transport.Request.Version;
import com.cloud.agent.transport.Response;
import com.cloud.cluster.ClusterManager;
import com.cloud.cluster.ClusterManagerListener;
import com.cloud.cluster.ClusteredAgentRebalanceService;
import com.cloud.cluster.ManagementServerHost;
import com.cloud.cluster.ManagementServerHostVO;
import com.cloud.cluster.StackMaid;
import com.cloud.cluster.agentlb.AgentLoadBalancerPlanner;
import com.cloud.cluster.agentlb.HostTransferMapVO;
import com.cloud.cluster.agentlb.HostTransferMapVO.HostTransferState;
import com.cloud.cluster.agentlb.dao.HostTransferMapDao;
import com.cloud.cluster.dao.ManagementServerHostDao;
import com.cloud.configuration.Config;
import com.cloud.configuration.dao.ConfigurationDao;
import com.cloud.exception.AgentUnavailableException;
import com.cloud.exception.OperationTimedoutException;
import com.cloud.host.Host;
import com.cloud.host.HostVO;
import com.cloud.host.Status;
import com.cloud.host.Status.Event;
import com.cloud.resource.ServerResource;
import com.cloud.storage.resource.DummySecondaryStorageResource;
import com.cloud.utils.DateUtil;
import com.cloud.utils.NumbersUtil;
import com.cloud.utils.component.Adapters;
import com.cloud.utils.component.ComponentLocator;
import com.cloud.utils.component.Inject;
import com.cloud.utils.concurrency.NamedThreadFactory;
import com.cloud.utils.db.SearchCriteria.Op;
import com.cloud.utils.db.SearchCriteria2;
import com.cloud.utils.db.SearchCriteriaService;
import com.cloud.utils.db.Transaction;
import com.cloud.utils.exception.CloudRuntimeException;
import com.cloud.utils.nio.Link;
import com.cloud.utils.nio.Task;
@Local(value = { AgentManager.class, ClusteredAgentRebalanceService.class })
public class ClusteredAgentManagerImpl extends AgentManagerImpl implements ClusterManagerListener, ClusteredAgentRebalanceService {
final static Logger s_logger = Logger.getLogger(ClusteredAgentManagerImpl.class);
private static final ScheduledExecutorService s_transferExecutor = Executors.newScheduledThreadPool(1, new NamedThreadFactory("Cluster-AgentTransferExecutor"));
private final long rebalanceTimeOut = 300000; // 5 mins - after this time remove the agent from the transfer list
public final static long STARTUP_DELAY = 5000;
public final static long SCAN_INTERVAL = 90000; // 90 seconds, it takes 60 sec for xenserver to fail login
public final static int ACQUIRE_GLOBAL_LOCK_TIMEOUT_FOR_COOPERATION = 5; // 5 seconds
public long _loadSize = 100;
protected Set<Long> _agentToTransferIds = new HashSet<Long>();
@Inject
protected ClusterManager _clusterMgr = null;
protected HashMap<String, SocketChannel> _peers;
protected HashMap<String, SSLEngine> _sslEngines;
private final Timer _timer = new Timer("ClusteredAgentManager Timer");
@Inject
protected ManagementServerHostDao _mshostDao;
@Inject
protected HostTransferMapDao _hostTransferDao;
@Inject(adapter = AgentLoadBalancerPlanner.class)
protected Adapters<AgentLoadBalancerPlanner> _lbPlanners;
@Inject
protected AgentManager _agentMgr;
protected ClusteredAgentManagerImpl() {
super();
}
@Override
public boolean configure(String name, Map<String, Object> xmlParams) throws ConfigurationException {
_peers = new HashMap<String, SocketChannel>(7);
_sslEngines = new HashMap<String, SSLEngine>(7);
_nodeId = _clusterMgr.getManagementNodeId();
s_logger.info("Configuring ClusterAgentManagerImpl. management server node id(msid): " + _nodeId);
ConfigurationDao configDao = ComponentLocator.getCurrentLocator().getDao(ConfigurationDao.class);
Map<String, String> params = configDao.getConfiguration(xmlParams);
String value = params.get(Config.DirectAgentLoadSize.key());
_loadSize = NumbersUtil.parseInt(value, 16);
ClusteredAgentAttache.initialize(this);
_clusterMgr.registerListener(this);
return super.configure(name, xmlParams);
}
@Override
public boolean start() {
if (!super.start()) {
return false;
}
_timer.schedule(new DirectAgentScanTimerTask(), STARTUP_DELAY, SCAN_INTERVAL);
// schedule transfer scan executor - if agent LB is enabled
if (_clusterMgr.isAgentRebalanceEnabled()) {
s_transferExecutor.scheduleAtFixedRate(getTransferScanTask(), 60000, ClusteredAgentRebalanceService.DEFAULT_TRANSFER_CHECK_INTERVAL,
TimeUnit.MILLISECONDS);
}
return true;
}
private void runDirectAgentScanTimerTask() {
scanDirectAgentToLoad();
}
private void scanDirectAgentToLoad() {
if (s_logger.isTraceEnabled()) {
s_logger.trace("Begin scanning directly connected hosts");
}
// for agents that are self-managed, threshold to be considered as disconnected is 3 ping intervals
long cutSeconds = (System.currentTimeMillis() >> 10) - (_pingInterval * 3);
List<HostVO> hosts = _hostDao.findAndUpdateDirectAgentToLoad(cutSeconds, _loadSize, _nodeId);
List<HostVO> appliances = _hostDao.findAndUpdateApplianceToLoad(cutSeconds, _nodeId);
hosts.addAll(appliances);
if (hosts != null && hosts.size() > 0) {
s_logger.debug("Found " + hosts.size() + " unmanaged direct hosts, processing connect for them...");
for (HostVO host : hosts) {
try {
AgentAttache agentattache = findAttache(host.getId());
if (agentattache != null) {
// already loaded, skip
if (agentattache.forForward()) {
if (s_logger.isInfoEnabled()) {
s_logger.info(host + " is detected down, but we have a forward attache running, disconnect this one before launching the host");
}
removeAgent(agentattache, Status.Disconnected);
} else {
continue;
}
}
if (s_logger.isDebugEnabled()) {
s_logger.debug("Loading directly connected host " + host.getId() + "(" + host.getName() + ")");
}
loadDirectlyConnectedHost(host, false);
} catch (Throwable e) {
s_logger.warn(" can not load directly connected host " + host.getId() + "(" + host.getName() + ") due to ",e);
}
}
}
if (s_logger.isTraceEnabled()) {
s_logger.trace("End scanning directly connected hosts");
}
}
private class DirectAgentScanTimerTask extends TimerTask {
@Override
public void run() {
try {
runDirectAgentScanTimerTask();
} catch (Throwable e) {
s_logger.error("Unexpected exception " + e.getMessage(), e);
}
}
}
@Override
public Task create(Task.Type type, Link link, byte[] data) {
return new ClusteredAgentHandler(type, link, data);
}
protected AgentAttache createAttache(long id) {
s_logger.debug("create forwarding ClusteredAgentAttache for " + id);
final AgentAttache attache = new ClusteredAgentAttache(this, id);
AgentAttache old = null;
synchronized (_agents) {
old = _agents.get(id);
_agents.put(id, attache);
}
if (old != null) {
old.disconnect(Status.Removed);
}
return attache;
}
@Override
protected AgentAttache createAttacheForConnect(HostVO host, Link link) {
s_logger.debug("create ClusteredAgentAttache for " + host.getId());
final AgentAttache attache = new ClusteredAgentAttache(this, host.getId(), link, host.isInMaintenanceStates());
link.attach(attache);
AgentAttache old = null;
synchronized (_agents) {
old = _agents.get(host.getId());
_agents.put(host.getId(), attache);
}
if (old != null) {
old.disconnect(Status.Removed);
}
return attache;
}
@Override
protected AgentAttache createAttacheForDirectConnect(HostVO host, ServerResource resource) {
if (resource instanceof DummySecondaryStorageResource) {
return new DummyAttache(this, host.getId(), false);
}
s_logger.debug("create ClusteredDirectAgentAttache for " + host.getId());
final DirectAgentAttache attache = new ClusteredDirectAgentAttache(this, host.getId(), _nodeId, resource, host.isInMaintenanceStates(), this);
AgentAttache old = null;
synchronized (_agents) {
old = _agents.get(host.getId());
_agents.put(host.getId(), attache);
}
if (old != null) {
old.disconnect(Status.Removed);
}
return attache;
}
@Override
protected boolean handleDisconnectWithoutInvestigation(AgentAttache attache, Status.Event event) {
return handleDisconnect(attache, event, false, true);
}
@Override
protected boolean handleDisconnectWithInvestigation(AgentAttache attache, Status.Event event) {
return handleDisconnect(attache, event, true, true);
}
protected boolean handleDisconnect(AgentAttache agent, Status.Event event, boolean investigate, boolean broadcast) {
boolean res;
if (!investigate) {
res = super.handleDisconnectWithoutInvestigation(agent, event);
} else {
res = super.handleDisconnectWithInvestigation(agent, event);
}
if (res) {
if (broadcast) {
notifyNodesInCluster(agent);
}
return true;
} else {
return false;
}
}
@Override
public boolean executeUserRequest(long hostId, Event event) throws AgentUnavailableException {
if (event == Event.AgentDisconnected) {
if (s_logger.isDebugEnabled()) {
s_logger.debug("Received agent disconnect event for host " + hostId);
}
AgentAttache attache = findAttache(hostId);
if (attache != null) {
handleDisconnect(attache, Event.AgentDisconnected, false, false);
}
return true;
} else {
return super.executeUserRequest(hostId, event);
}
}
@Override
public boolean reconnect(final long hostId) {
Boolean result;
try {
result = _clusterMgr.propagateAgentEvent(hostId, Event.ShutdownRequested);
if (result != null) {
return result;
}
} catch (AgentUnavailableException e) {
s_logger.debug("cannot propagate agent reconnect because agent is not available", e);
return false;
}
return super.reconnect(hostId);
}
public void notifyNodesInCluster(AgentAttache attache) {
s_logger.debug("Notifying other nodes of to disconnect");
Command[] cmds = new Command[] { new ChangeAgentCommand(attache.getId(), Event.AgentDisconnected) };
_clusterMgr.broadcast(attache.getId(), cmds);
}
protected static void logT(byte[] bytes, final String msg) {
s_logger.trace("Seq " + Request.getAgentId(bytes) + "-" + Request.getSequence(bytes) + ": MgmtId " + Request.getManagementServerId(bytes) + ": "
+ (Request.isRequest(bytes) ? "Req: " : "Resp: ") + msg);
}
protected static void logD(byte[] bytes, final String msg) {
s_logger.debug("Seq " + Request.getAgentId(bytes) + "-" + Request.getSequence(bytes) + ": MgmtId " + Request.getManagementServerId(bytes) + ": "
+ (Request.isRequest(bytes) ? "Req: " : "Resp: ") + msg);
}
protected static void logI(byte[] bytes, final String msg) {
s_logger.info("Seq " + Request.getAgentId(bytes) + "-" + Request.getSequence(bytes) + ": MgmtId " + Request.getManagementServerId(bytes) + ": "
+ (Request.isRequest(bytes) ? "Req: " : "Resp: ") + msg);
}
public boolean routeToPeer(String peer, byte[] bytes) {
int i = 0;
SocketChannel ch = null;
SSLEngine sslEngine = null;
while (i++ < 5) {
ch = connectToPeer(peer, ch);
if (ch == null) {
try {
logD(bytes, "Unable to route to peer: " + Request.parse(bytes).toString());
} catch (Exception e) {
}
return false;
}
sslEngine = getSSLEngine(peer);
if (sslEngine == null) {
logD(bytes, "Unable to get SSLEngine of peer: " + peer);
return false;
}
try {
if (s_logger.isDebugEnabled()) {
logD(bytes, "Routing to peer");
}
Link.write(ch, new ByteBuffer[] { ByteBuffer.wrap(bytes) }, sslEngine);
return true;
} catch (IOException e) {
try {
logI(bytes, "Unable to route to peer: " + Request.parse(bytes).toString() + " due to " + e.getMessage());
} catch (Exception ex) {
}
}
}
return false;
}
public String findPeer(long hostId) {
return _clusterMgr.getPeerName(hostId);
}
public SSLEngine getSSLEngine(String peerName) {
return _sslEngines.get(peerName);
}
public void cancel(String peerName, long hostId, long sequence, String reason) {
CancelCommand cancel = new CancelCommand(sequence, reason);
Request req = new Request(hostId, _nodeId, cancel, true);
req.setControl(true);
routeToPeer(peerName, req.getBytes());
}
public void closePeer(String peerName) {
synchronized (_peers) {
SocketChannel ch = _peers.get(peerName);
if (ch != null) {
try {
ch.close();
} catch (IOException e) {
s_logger.warn("Unable to close peer socket connection to " + peerName);
}
}
_peers.remove(peerName);
_sslEngines.remove(peerName);
}
}
public SocketChannel connectToPeer(String peerName, SocketChannel prevCh) {
synchronized (_peers) {
SocketChannel ch = _peers.get(peerName);
SSLEngine sslEngine = null;
if (prevCh != null) {
try {
prevCh.close();
} catch (Exception e) {
}
}
if (ch == null || ch == prevCh) {
ManagementServerHostVO ms = _clusterMgr.getPeer(peerName);
if (ms == null) {
s_logger.info("Unable to find peer: " + peerName);
return null;
}
String ip = ms.getServiceIP();
InetAddress addr;
try {
addr = InetAddress.getByName(ip);
} catch (UnknownHostException e) {
throw new CloudRuntimeException("Unable to resolve " + ip);
}
try {
ch = SocketChannel.open(new InetSocketAddress(addr, _port));
ch.configureBlocking(true); // make sure we are working at blocking mode
ch.socket().setKeepAlive(true);
ch.socket().setSoTimeout(60 * 1000);
try {
SSLContext sslContext = Link.initSSLContext(true);
sslEngine = sslContext.createSSLEngine(ip, _port);
sslEngine.setUseClientMode(true);
Link.doHandshake(ch, sslEngine, true);
s_logger.info("SSL: Handshake done");
} catch (Exception e) {
throw new IOException("SSL: Fail to init SSL! " + e);
}
if (s_logger.isDebugEnabled()) {
s_logger.debug("Connection to peer opened: " + peerName + ", ip: " + ip);
}
_peers.put(peerName, ch);
_sslEngines.put(peerName, sslEngine);
} catch (IOException e) {
s_logger.warn("Unable to connect to peer management server: " + peerName + ", ip: " + ip + " due to " + e.getMessage(), e);
return null;
}
}
if (s_logger.isTraceEnabled()) {
s_logger.trace("Found open channel for peer: " + peerName);
}
return ch;
}
}
public SocketChannel connectToPeer(long hostId, SocketChannel prevCh) {
String peerName = _clusterMgr.getPeerName(hostId);
if (peerName == null) {
return null;
}
return connectToPeer(peerName, prevCh);
}
@Override
protected AgentAttache getAttache(final Long hostId) throws AgentUnavailableException {
assert (hostId != null) : "Who didn't check their id value?";
HostVO host = _hostDao.findById(hostId);
if (host == null) {
throw new AgentUnavailableException("Can't find the host ", hostId);
}
AgentAttache agent = findAttache(hostId);
if (agent == null) {
if (host.getStatus() == Status.Up && (host.getManagementServerId() != null && host.getManagementServerId() != _nodeId)) {
agent = createAttache(hostId);
}
}
if (agent == null) {
AgentUnavailableException ex = new AgentUnavailableException("Host with specified id is not in the right state: " + host.getStatus(), hostId);
ex.addProxyObject(host, hostId, "hostId");
throw ex;
}
return agent;
}
@Override
public boolean stop() {
if (_peers != null) {
for (SocketChannel ch : _peers.values()) {
try {
s_logger.info("Closing: " + ch.toString());
ch.close();
} catch (IOException e) {
}
}
}
_timer.cancel();
//cancel all transfer tasks
s_transferExecutor.shutdownNow();
cleanupTransferMap(_nodeId);
return super.stop();
}
@Override
public void startDirectlyConnectedHosts() {
// override and let it be dummy for purpose, we will scan and load direct agents periodically.
// We may also pickup agents that have been left over from other crashed management server
}
public class ClusteredAgentHandler extends AgentHandler {
public ClusteredAgentHandler(Task.Type type, Link link, byte[] data) {
super(type, link, data);
}
@Override
protected void doTask(final Task task) throws Exception {
Transaction txn = Transaction.open(Transaction.CLOUD_DB);
try {
if (task.getType() != Task.Type.DATA) {
super.doTask(task);
return;
}
final byte[] data = task.getData();
Version ver = Request.getVersion(data);
if (ver.ordinal() != Version.v1.ordinal() && ver.ordinal() != Version.v3.ordinal()) {
s_logger.warn("Wrong version for clustered agent request");
super.doTask(task);
return;
}
long hostId = Request.getAgentId(data);
Link link = task.getLink();
if (Request.fromServer(data)) {
AgentAttache agent = findAttache(hostId);
if (Request.isControl(data)) {
if (agent == null) {
logD(data, "No attache to process cancellation");
return;
}
Request req = Request.parse(data);
Command[] cmds = req.getCommands();
CancelCommand cancel = (CancelCommand) cmds[0];
if (s_logger.isDebugEnabled()) {
logD(data, "Cancel request received");
}
agent.cancel(cancel.getSequence());
return;
}
try {
if (agent == null || agent.isClosed()) {
throw new AgentUnavailableException("Unable to route to agent ", hostId);
}
if (Request.isRequest(data) && Request.requiresSequentialExecution(data)) {
// route it to the agent.
// But we have the serialize the control commands here so we have
// to deserialize this and send it through the agent attache.
Request req = Request.parse(data);
agent.send(req, null);
return;
} else {
if (agent instanceof Routable) {
Routable cluster = (Routable) agent;
cluster.routeToAgent(data);
} else {
agent.send(Request.parse(data));
}
return;
}
} catch (AgentUnavailableException e) {
logD(data, e.getMessage());
cancel(Long.toString(Request.getManagementServerId(data)), hostId, Request.getSequence(data), e.getMessage());
}
} else {
long mgmtId = Request.getManagementServerId(data);
if (mgmtId != -1 && mgmtId != _nodeId) {
routeToPeer(Long.toString(mgmtId), data);
if (Request.requiresSequentialExecution(data)) {
AgentAttache attache = (AgentAttache) link.attachment();
if (attache != null) {
attache.sendNext(Request.getSequence(data));
} else if (s_logger.isDebugEnabled()) {
logD(data, "No attache to process " + Request.parse(data).toString());
}
}
return;
} else {
if (Request.isRequest(data)) {
super.doTask(task);
} else {
// received an answer.
final Response response = Response.parse(data);
AgentAttache attache = findAttache(response.getAgentId());
if (attache == null) {
s_logger.info("SeqA " + response.getAgentId() + "-" + response.getSequence() + "Unable to find attache to forward " + response.toString());
return;
}
if (!attache.processAnswers(response.getSequence(), response)) {
s_logger.info("SeqA " + attache.getId() + "-" + response.getSequence() + ": Response is not processed: " + response.toString());
}
}
return;
}
}
} finally {
txn.close();
}
}
}
@Override
public void onManagementNodeJoined(List<ManagementServerHostVO> nodeList, long selfNodeId) {
}
@Override
public void onManagementNodeLeft(List<ManagementServerHostVO> nodeList, long selfNodeId) {
for (ManagementServerHostVO vo : nodeList) {
s_logger.info("Marking hosts as disconnected on Management server" + vo.getMsid());
long lastPing = (System.currentTimeMillis() >> 10) - _pingTimeout;
_hostDao.markHostsAsDisconnected(vo.getMsid(), lastPing);
s_logger.info("Deleting entries from op_host_transfer table for Management server " + vo.getMsid());
cleanupTransferMap(vo.getMsid());
}
}
@Override
public void onManagementNodeIsolated() {
}
@Override
public void removeAgent(AgentAttache attache, Status nextState) {
if (attache == null) {
return;
}
super.removeAgent(attache, nextState);
}
@Override
public boolean executeRebalanceRequest(long agentId, long currentOwnerId, long futureOwnerId, Event event) throws AgentUnavailableException, OperationTimedoutException {
boolean result = false;
if (event == Event.RequestAgentRebalance) {
return setToWaitForRebalance(agentId, currentOwnerId, futureOwnerId);
} else if (event == Event.StartAgentRebalance) {
try {
result = rebalanceHost(agentId, currentOwnerId, futureOwnerId);
} catch (Exception e) {
s_logger.warn("Unable to rebalance host id=" + agentId, e);
}
}
return result;
}
@Override
public void scheduleRebalanceAgents() {
_timer.schedule(new AgentLoadBalancerTask(), 30000);
}
public class AgentLoadBalancerTask extends TimerTask {
protected volatile boolean cancelled = false;
public AgentLoadBalancerTask() {
s_logger.debug("Agent load balancer task created");
}
@Override
public synchronized boolean cancel() {
if (!cancelled) {
cancelled = true;
s_logger.debug("Agent load balancer task cancelled");
return super.cancel();
}
return true;
}
@Override
public synchronized void run() {
try {
if (!cancelled) {
startRebalanceAgents();
if (s_logger.isInfoEnabled()) {
s_logger.info("The agent load balancer task is now being cancelled");
}
cancelled = true;
}
} catch(Throwable e) {
s_logger.error("Unexpected exception " + e.toString(), e);
}
}
}
public void startRebalanceAgents() {
s_logger.debug("Management server " + _nodeId + " is asking other peers to rebalance their agents");
List<ManagementServerHostVO> allMS = _mshostDao.listBy(ManagementServerHost.State.Up);
SearchCriteriaService<HostVO, HostVO> sc = SearchCriteria2.create(HostVO.class);
sc.addAnd(sc.getEntity().getManagementServerId(), Op.NNULL);
sc.addAnd(sc.getEntity().getType(), Op.EQ, Host.Type.Routing);
List<HostVO> allManagedAgents = sc.list();
int avLoad = 0;
if (!allManagedAgents.isEmpty() && !allMS.isEmpty()) {
avLoad = allManagedAgents.size() / allMS.size();
} else {
if (s_logger.isDebugEnabled()) {
s_logger.debug("There are no hosts to rebalance in the system. Current number of active management server nodes in the system is " + allMS.size() + "; number of managed agents is " + allManagedAgents.size());
}
return;
}
if (avLoad == 0L) {
if (s_logger.isDebugEnabled()) {
s_logger.debug("As calculated average load is less than 1, rounding it to 1");
}
avLoad = 1;
}
for (ManagementServerHostVO node : allMS) {
if (node.getMsid() != _nodeId) {
List<HostVO> hostsToRebalance = new ArrayList<HostVO>();
for (AgentLoadBalancerPlanner lbPlanner : _lbPlanners) {
hostsToRebalance = lbPlanner.getHostsToRebalance(node.getMsid(), avLoad);
if (hostsToRebalance != null && !hostsToRebalance.isEmpty()) {
break;
} else {
s_logger.debug("Agent load balancer planner " + lbPlanner.getName() + " found no hosts to be rebalanced from management server " + node.getMsid());
}
}
if (hostsToRebalance != null && !hostsToRebalance.isEmpty()) {
s_logger.debug("Found " + hostsToRebalance.size() + " hosts to rebalance from management server " + node.getMsid());
for (HostVO host : hostsToRebalance) {
long hostId = host.getId();
s_logger.debug("Asking management server " + node.getMsid() + " to give away host id=" + hostId);
boolean result = true;
if (_hostTransferDao.findById(hostId) != null) {
s_logger.warn("Somebody else is already rebalancing host id: " + hostId);
continue;
}
HostTransferMapVO transfer = null;
try {
transfer = _hostTransferDao.startAgentTransfering(hostId, node.getMsid(), _nodeId);
Answer[] answer = sendRebalanceCommand(node.getMsid(), hostId, node.getMsid(), _nodeId, Event.RequestAgentRebalance);
if (answer == null) {
s_logger.warn("Failed to get host id=" + hostId + " from management server " + node.getMsid());
result = false;
}
} catch (Exception ex) {
s_logger.warn("Failed to get host id=" + hostId + " from management server " + node.getMsid(), ex);
result = false;
} finally {
if (transfer != null) {
HostTransferMapVO transferState = _hostTransferDao.findByIdAndFutureOwnerId(transfer.getId(), _nodeId);
if (!result && transferState != null && transferState.getState() == HostTransferState.TransferRequested) {
if (s_logger.isDebugEnabled()) {
s_logger.debug("Removing mapping from op_host_transfer as it failed to be set to transfer mode");
}
//just remove the mapping (if exists) as nothing was done on the peer management server yet
_hostTransferDao.remove(transfer.getId());
}
}
}
}
} else {
s_logger.debug("Found no hosts to rebalance from the management server " + node.getMsid());
}
}
}
}
private Answer[] sendRebalanceCommand(long peer, long agentId, long currentOwnerId, long futureOwnerId, Event event) {
TransferAgentCommand transfer = new TransferAgentCommand(agentId, currentOwnerId, futureOwnerId, event);
Commands commands = new Commands(OnError.Stop);
commands.addCommand(transfer);
Command[] cmds = commands.toCommands();
try {
if (s_logger.isDebugEnabled()) {
s_logger.debug("Forwarding " + cmds[0].toString() + " to " + peer);
}
String peerName = Long.toString(peer);
Answer[] answers = _clusterMgr.execute(peerName, agentId, cmds, true);
return answers;
} catch (Exception e) {
s_logger.warn("Caught exception while talking to " + currentOwnerId, e);
return null;
}
}
private Runnable getTransferScanTask() {
return new Runnable() {
@Override
public void run() {
try {
if (s_logger.isTraceEnabled()) {
s_logger.trace("Clustered agent transfer scan check, management server id:" + _nodeId);
}
synchronized (_agentToTransferIds) {
if (_agentToTransferIds.size() > 0) {
s_logger.debug("Found " + _agentToTransferIds.size() + " agents to transfer");
//for (Long hostId : _agentToTransferIds) {
for (Iterator<Long> iterator = _agentToTransferIds.iterator(); iterator.hasNext();) {
Long hostId = iterator.next();
AgentAttache attache = findAttache(hostId);
// if the thread:
// 1) timed out waiting for the host to reconnect
// 2) recipient management server is not active any more
// 3) if the management server doesn't own the host any more
// remove the host from re-balance list and delete from op_host_transfer DB
// no need to do anything with the real attache as we haven't modified it yet
Date cutTime = DateUtil.currentGMTTime();
HostTransferMapVO transferMap = _hostTransferDao.findActiveHostTransferMapByHostId(hostId, new Date(cutTime.getTime() - rebalanceTimeOut));
if (transferMap == null) {
s_logger.debug("Timed out waiting for the host id=" + hostId + " to be ready to transfer, skipping rebalance for the host");
iterator.remove();
_hostTransferDao.completeAgentTransfer(hostId);
continue;
}
if (transferMap.getInitialOwner() != _nodeId || attache.forForward()) {
s_logger.debug("Management server " + _nodeId + " doesn't own host id=" + hostId + " any more, skipping rebalance for the host");
iterator.remove();
_hostTransferDao.completeAgentTransfer(hostId);
continue;
}
ManagementServerHostVO ms = _mshostDao.findByMsid(transferMap.getFutureOwner());
if (ms != null && ms.getState() != ManagementServerHost.State.Up) {
s_logger.debug("Can't transfer host " + hostId + " as it's future owner is not in UP state: " + ms + ", skipping rebalance for the host");
iterator.remove();
_hostTransferDao.completeAgentTransfer(hostId);
continue;
}
if (attache.getQueueSize() == 0 && attache.getNonRecurringListenersSize() == 0) {
iterator.remove();
try {
_executor.execute(new RebalanceTask(hostId, transferMap.getInitialOwner(), transferMap.getFutureOwner()));
} catch (RejectedExecutionException ex) {
s_logger.warn("Failed to submit rebalance task for host id=" + hostId + "; postponing the execution");
continue;
}
} else {
s_logger.debug("Agent " + hostId + " can't be transfered yet as its request queue size is " + attache.getQueueSize() + " and listener queue size is " + attache.getNonRecurringListenersSize());
}
}
} else {
if (s_logger.isTraceEnabled()) {
s_logger.trace("Found no agents to be transfered by the management server " + _nodeId);
}
}
}
} catch (Throwable e) {
s_logger.error("Problem with the clustered agent transfer scan check!", e);
}
}
};
}
private boolean setToWaitForRebalance(final long hostId, long currentOwnerId, long futureOwnerId) {
s_logger.debug("Adding agent " + hostId + " to the list of agents to transfer");
synchronized (_agentToTransferIds) {
return _agentToTransferIds.add(hostId);
}
}
protected boolean rebalanceHost(final long hostId, long currentOwnerId, long futureOwnerId) throws AgentUnavailableException{
boolean result = true;
if (currentOwnerId == _nodeId) {
if (!startRebalance(hostId)) {
s_logger.debug("Failed to start agent rebalancing");
finishRebalance(hostId, futureOwnerId, Event.RebalanceFailed);
return false;
}
try {
Answer[] answer = sendRebalanceCommand(futureOwnerId, hostId, currentOwnerId, futureOwnerId, Event.StartAgentRebalance);
if (answer == null || !answer[0].getResult()) {
result = false;
}
} catch (Exception ex) {
s_logger.warn("Host " + hostId + " failed to connect to the management server " + futureOwnerId + " as a part of rebalance process", ex);
result = false;
}
if (result) {
s_logger.debug("Successfully transfered host id=" + hostId + " to management server " + futureOwnerId);
finishRebalance(hostId, futureOwnerId, Event.RebalanceCompleted);
} else {
s_logger.warn("Failed to transfer host id=" + hostId + " to management server " + futureOwnerId);
finishRebalance(hostId, futureOwnerId, Event.RebalanceFailed);
}
} else if (futureOwnerId == _nodeId) {
HostVO host = _hostDao.findById(hostId);
try {
if (s_logger.isDebugEnabled()) {
s_logger.debug("Loading directly connected host " + host.getId() + "(" + host.getName() + ") to the management server " + _nodeId + " as a part of rebalance process");
}
result = loadDirectlyConnectedHost(host, true);
} catch (Exception ex) {
s_logger.warn("Failed to load directly connected host " + host.getId() + "(" + host.getName() + ") to the management server " + _nodeId + " as a part of rebalance process due to:", ex);
result = false;
}
if (result) {
s_logger.debug("Successfully loaded directly connected host " + host.getId() + "(" + host.getName() + ") to the management server " + _nodeId + " as a part of rebalance process");
} else {
s_logger.warn("Failed to load directly connected host " + host.getId() + "(" + host.getName() + ") to the management server " + _nodeId + " as a part of rebalance process");
}
}
return result;
}
protected void finishRebalance(final long hostId, long futureOwnerId, Event event){
boolean success = (event == Event.RebalanceCompleted) ? true : false;
if (s_logger.isDebugEnabled()) {
s_logger.debug("Finishing rebalancing for the agent " + hostId + " with event " + event);
}
AgentAttache attache = findAttache(hostId);
if (attache == null || !(attache instanceof ClusteredAgentAttache)) {
s_logger.debug("Unable to find forward attache for the host id=" + hostId + ", assuming that the agent disconnected already");
_hostTransferDao.completeAgentTransfer(hostId);
return;
}
ClusteredAgentAttache forwardAttache = (ClusteredAgentAttache)attache;
if (success) {
//1) Set transfer mode to false - so the agent can start processing requests normally
forwardAttache.setTransferMode(false);
//2) Get all transfer requests and route them to peer
Request requestToTransfer = forwardAttache.getRequestToTransfer();
while (requestToTransfer != null) {
s_logger.debug("Forwarding request " + requestToTransfer.getSequence() + " held in transfer attache " + hostId + " from the management server " + _nodeId + " to " + futureOwnerId);
boolean routeResult = routeToPeer(Long.toString(futureOwnerId), requestToTransfer.getBytes());
if (!routeResult) {
logD(requestToTransfer.getBytes(), "Failed to route request to peer");
}
requestToTransfer = forwardAttache.getRequestToTransfer();
}
s_logger.debug("Management server " + _nodeId + " completed agent " + hostId + " rebalance to " + futureOwnerId);
} else {
failRebalance(hostId);
}
s_logger.debug("Management server " + _nodeId + " completed agent " + hostId + " rebalance");
_hostTransferDao.completeAgentTransfer(hostId);
}
protected void failRebalance(final long hostId){
try {
s_logger.debug("Management server " + _nodeId + " failed to rebalance agent " + hostId);
_hostTransferDao.completeAgentTransfer(hostId);
handleDisconnectWithoutInvestigation(findAttache(hostId), Event.RebalanceFailed);
} catch (Exception ex) {
s_logger.warn("Failed to reconnect host id=" + hostId + " as a part of failed rebalance task cleanup");
}
}
protected boolean startRebalance(final long hostId) {
HostVO host = _hostDao.findById(hostId);
if (host == null || host.getRemoved() != null) {
s_logger.warn("Unable to find host record, fail start rebalancing process");
return false;
}
synchronized (_agents) {
ClusteredDirectAgentAttache attache = (ClusteredDirectAgentAttache)_agents.get(hostId);
if (attache != null && attache.getQueueSize() == 0 && attache.getNonRecurringListenersSize() == 0) {
handleDisconnectWithoutInvestigation(attache, Event.StartAgentRebalance);
ClusteredAgentAttache forwardAttache = (ClusteredAgentAttache)createAttache(hostId);
if (forwardAttache == null) {
s_logger.warn("Unable to create a forward attache for the host " + hostId + " as a part of rebalance process");
return false;
}
s_logger.debug("Putting agent id=" + hostId + " to transfer mode");
forwardAttache.setTransferMode(true);
_agents.put(hostId, forwardAttache);
} else {
if (attache == null) {
s_logger.warn("Attache for the agent " + hostId + " no longer exists on management server " + _nodeId + ", can't start host rebalancing");
} else {
s_logger.warn("Attache for the agent " + hostId + " has request queue size= " + attache.getQueueSize() + " and listener queue size " + attache.getNonRecurringListenersSize() + ", can't start host rebalancing");
}
return false;
}
}
_hostTransferDao.startAgentTransfer(hostId);
return true;
}
protected void cleanupTransferMap(long msId) {
List<HostTransferMapVO> hostsJoingingCluster = _hostTransferDao.listHostsJoiningCluster(msId);
for (HostTransferMapVO hostJoingingCluster : hostsJoingingCluster) {
_hostTransferDao.remove(hostJoingingCluster.getId());
}
List<HostTransferMapVO> hostsLeavingCluster = _hostTransferDao.listHostsLeavingCluster(msId);
for (HostTransferMapVO hostLeavingCluster : hostsLeavingCluster) {
_hostTransferDao.remove(hostLeavingCluster.getId());
}
}
protected class RebalanceTask implements Runnable {
Long hostId = null;
Long currentOwnerId = null;
Long futureOwnerId = null;
public RebalanceTask(long hostId, long currentOwnerId, long futureOwnerId) {
this.hostId = hostId;
this.currentOwnerId = currentOwnerId;
this.futureOwnerId = futureOwnerId;
}
@Override
public void run() {
try {
if (s_logger.isDebugEnabled()) {
s_logger.debug("Rebalancing host id=" + hostId);
}
rebalanceHost(hostId, currentOwnerId, futureOwnerId);
} catch (Exception e) {
s_logger.warn("Unable to rebalance host id=" + hostId, e);
} finally {
StackMaid.current().exitCleanup();
}
}
}
}