com.hazelcast.web.ClusteredSessionService Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2016, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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.hazelcast.web;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.core.IMap;
import com.hazelcast.instance.OutOfMemoryErrorDispatcher;
import com.hazelcast.internal.serialization.SerializationService;
import com.hazelcast.logging.ILogger;
import com.hazelcast.logging.Logger;
import com.hazelcast.map.EntryProcessor;
import com.hazelcast.map.impl.MapEntrySimple;
import com.hazelcast.nio.serialization.Data;
import com.hazelcast.spi.impl.SerializationServiceSupport;
import com.hazelcast.util.EmptyStatement;
import com.hazelcast.util.ExceptionUtil;
import com.hazelcast.web.entryprocessor.DeleteSessionEntryProcessor;
import com.hazelcast.web.entryprocessor.GetAttributeEntryProcessor;
import com.hazelcast.web.entryprocessor.GetAttributeNamesEntryProcessor;
import com.hazelcast.web.entryprocessor.GetSessionStateEntryProcessor;
import com.hazelcast.web.entryprocessor.SessionUpdateEntryProcessor;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import java.util.AbstractMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
/**
* ClusteredSessionService is a proxy class which delegates all
* operations on distributed map to hazelcast cluster used for session
* replication. ClusteredSessionService is also responsible for safety
* of the cluster connection. If a map operation fails due to network
* issued, a background thread always retries connection and ensures the
* safety of connection.
*/
public class ClusteredSessionService {
/**
* The constant LOGGER.
*/
protected static final ILogger LOGGER = Logger.getLogger(ClusteredSessionService.class);
private static final long CLUSTER_CHECK_INTERVAL = 5L;
private static final long RETRY_MILLIS = 7000;
private volatile IMap clusterMap;
private volatile SerializationServiceSupport sss;
private volatile HazelcastInstance hazelcastInstance;
private final FilterConfig filterConfig;
private final Properties properties;
private final String clusterMapName;
private final Queue> orphanSessions = new
LinkedBlockingQueue>();
private volatile boolean failedConnection = true;
private volatile long lastConnectionTry;
private final ScheduledExecutorService es = Executors.newSingleThreadScheduledExecutor(new EnsureInstanceThreadFactory());
/**
* Instantiates a new Clustered session service.
*
* @param filterConfig the filter config
* @param properties the properties
* @param clusterMapName the cluster map name
*/
public ClusteredSessionService(FilterConfig filterConfig, Properties properties, String clusterMapName) {
this.filterConfig = filterConfig;
this.properties = properties;
this.clusterMapName = clusterMapName;
try {
init();
} catch (Exception e) {
ExceptionUtil.rethrow(e);
}
}
public void setFailedConnection(boolean failedConnection) {
this.failedConnection = failedConnection;
}
public void init() throws Exception {
ensureInstance();
es.scheduleWithFixedDelay(new Runnable() {
public void run() {
try {
ensureInstance();
} catch (Exception e) {
if (LOGGER.isFinestEnabled()) {
LOGGER.finest("Cannot connect hazelcast server", e);
}
}
}
}, 2 * CLUSTER_CHECK_INTERVAL, CLUSTER_CHECK_INTERVAL, TimeUnit.SECONDS);
}
private void ensureInstance() throws Exception {
if (failedConnection && System.currentTimeMillis() > lastConnectionTry + RETRY_MILLIS) {
synchronized (this) {
try {
if (failedConnection && System.currentTimeMillis() > lastConnectionTry + RETRY_MILLIS) {
reconnectHZInstance();
clearOrphanSessionQueue();
}
} catch (Exception e) {
setFailedConnection(true);
if (LOGGER.isFinestEnabled()) {
LOGGER.finest("Cannot connect hazelcast server", e);
}
}
}
}
}
private void reconnectHZInstance() throws ServletException {
LOGGER.info("Retrying the connection!!");
lastConnectionTry = System.currentTimeMillis();
hazelcastInstance = HazelcastInstanceLoader.createInstance(this, filterConfig, properties, clusterMapName);
clusterMap = hazelcastInstance.getMap(clusterMapName);
sss = (SerializationServiceSupport) hazelcastInstance;
setFailedConnection(false);
LOGGER.info("Successfully Connected!");
}
private void clearOrphanSessionQueue() {
AbstractMap.SimpleEntry sessionIdEntry = orphanSessions.poll();
while (sessionIdEntry != null) {
if (!deleteSession(sessionIdEntry.getKey(), sessionIdEntry.getValue())) {
// do not continue
sessionIdEntry = null;
} else {
sessionIdEntry = orphanSessions.poll();
}
}
}
/**
* Execute on key.
*
* @param sessionId the session id
* @param processor the processor
* @return the object
* @throws Exception
*/
Object executeOnKey(String sessionId, EntryProcessor processor) throws Exception {
try {
return clusterMap.executeOnKey(sessionId, processor);
} catch (Exception e) {
LOGGER.finest("Cannot connect hazelcast server", e);
throw e;
}
}
/**
* Gets attributes.
*
* @param sessionId the session id
* @return the attributes
* @throws Exception the exception
*/
Set> getAttributes(String sessionId) throws Exception {
GetSessionStateEntryProcessor entryProcessor = new GetSessionStateEntryProcessor();
SessionState sessionState = (SessionState) executeOnKey(sessionId, entryProcessor);
if (sessionState == null) {
return null;
}
Map dataAttributes = sessionState.getAttributes();
Set> attributes = new HashSet>(dataAttributes.size());
for (Map.Entry entry : dataAttributes.entrySet()) {
String key = entry.getKey();
Object value = sss.getSerializationService().toObject(entry.getValue());
attributes.add(new MapEntrySimple(key, value));
}
return attributes;
}
/**
* Gets attribute.
*
* @param sessionId the session id
* @param attributeName the attribute name
* @return the attribute
* @throws Exception the exception
*/
Object getAttribute(String sessionId, String attributeName) throws Exception {
GetAttributeEntryProcessor entryProcessor = new GetAttributeEntryProcessor(attributeName);
return executeOnKey(sessionId, entryProcessor);
}
/**
* Delete attribute.
*
* @param sessionId the session id
* @param attributeName the attribute name
* @throws Exception the exception
*/
void deleteAttribute(String sessionId, String attributeName) throws Exception {
setAttribute(sessionId, attributeName, null);
}
/**
* Sets attribute.
*
* @param sessionId the session id
* @param attributeName the attribute name
* @param value the value
* @throws Exception the exception
*/
void setAttribute(String sessionId, String attributeName, Object value) throws Exception {
Data dataValue = (value == null) ? null : sss.getSerializationService().toData(value);
SessionUpdateEntryProcessor sessionUpdateProcessor = new SessionUpdateEntryProcessor(attributeName, dataValue);
executeOnKey(sessionId, sessionUpdateProcessor);
}
/**
* Delete session.
*
* @param sessionId sessionId
* @param invalidate if true remove the distributed session, otherwise just
* remove the jvm reference
* @return the boolean
*/
public boolean deleteSession(String sessionId, boolean invalidate) {
try {
doDeleteSession(sessionId, invalidate);
return true;
} catch (Exception e) {
orphanSessions.add(new AbstractMap.SimpleEntry(sessionId, invalidate));
return false;
}
}
private void doDeleteSession(String sessionId, boolean invalidate) throws Exception {
DeleteSessionEntryProcessor entryProcessor = new DeleteSessionEntryProcessor(invalidate);
executeOnKey(sessionId, entryProcessor);
}
/**
* Gets attribute names.
*
* @param id the id
* @return the attribute names
* @throws Exception the exception
*/
public Set getAttributeNames(String id) throws Exception {
return (Set) executeOnKey(id, new GetAttributeNamesEntryProcessor());
}
/**
* Update attributes.
*
* @param id the id
* @param updates the updates
* @throws Exception the exception
*/
public void updateAttributes(String id, Map updates) throws Exception {
SerializationService ss = sss.getSerializationService();
SessionUpdateEntryProcessor sessionUpdate = new SessionUpdateEntryProcessor(updates.size());
for (Map.Entry entry : updates.entrySet()) {
String name = entry.getKey();
Object value = entry.getValue();
sessionUpdate.getAttributes().put(name, ss.toData(value));
}
executeOnKey(id, sessionUpdate);
}
/**
* Destroy void.
*/
public void destroy() {
if (hazelcastInstance != null) {
try {
hazelcastInstance.getLifecycleService().shutdown();
es.shutdown();
} catch (Exception ignored) {
EmptyStatement.ignore(ignored);
}
}
}
/**
* Internal ThreadFactory to create threads which checks hazelcast instance
*/
private static final class EnsureInstanceThreadFactory implements ThreadFactory {
public Thread newThread(final Runnable r) {
final Thread thread = new EnsureInstanceThread(r, ".hazelcast-wm.ensureInstance");
thread.setDaemon(true);
return thread;
}
}
/**
* Runnable thread adapter to capture exceptions and notify Hazelcast about them
*/
private static final class EnsureInstanceThread extends Thread {
private EnsureInstanceThread(final Runnable target, final String name) {
super(target, name);
}
public void run() {
try {
super.run();
} catch (OutOfMemoryError e) {
OutOfMemoryErrorDispatcher.onOutOfMemory(e);
}
}
}
}
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