an implementation of an exclusive lock in SQL to ensure that only one JDBC message store is run against a database at once to fix AMQ-831. For documentation on this feature see: http://activemq.org/site/jdbc-master-slave.html

git-svn-id: https://svn.apache.org/repos/asf/incubator/activemq/trunk@424328 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
James Strachan 2006-07-21 14:10:45 +00:00
parent e2f0ef3c5e
commit 90d0c4b38b
6 changed files with 368 additions and 60 deletions

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@ -558,6 +558,7 @@ public class BrokerService implements Service, Serializable {
public PersistenceAdapter getPersistenceAdapter() throws IOException {
if (persistenceAdapter == null) {
persistenceAdapter = createPersistenceAdapter();
configureService(persistenceAdapter);
}
return persistenceAdapter;
}
@ -771,6 +772,54 @@ public class BrokerService implements Service, Serializable {
getPersistenceAdapter().deleteAllMessages();
}
public boolean isDeleteAllMessagesOnStartup() {
return deleteAllMessagesOnStartup;
}
/**
* Sets whether or not all messages are deleted on startup - mostly only
* useful for testing.
*/
public void setDeleteAllMessagesOnStartup(boolean deletePersistentMessagesOnStartup) {
this.deleteAllMessagesOnStartup = deletePersistentMessagesOnStartup;
}
public URI getVmConnectorURI() {
if (vmConnectorURI == null) {
try {
vmConnectorURI = new URI("vm://" + getBrokerName());
}
catch (URISyntaxException e) {
}
}
return vmConnectorURI;
}
public void setVmConnectorURI(URI vmConnectorURI) {
this.vmConnectorURI = vmConnectorURI;
}
/**
* @return Returns the shutdownOnMasterFailure.
*/
public boolean isShutdownOnMasterFailure(){
return shutdownOnMasterFailure;
}
/**
* @param shutdownOnMasterFailure The shutdownOnMasterFailure to set.
*/
public void setShutdownOnMasterFailure(boolean shutdownOnMasterFailure){
this.shutdownOnMasterFailure=shutdownOnMasterFailure;
}
public boolean isKeepDurableSubsActive() {
return keepDurableSubsActive;
}
public void setKeepDurableSubsActive(boolean keepDurableSubsActive) {
this.keepDurableSubsActive = keepDurableSubsActive;
}
// Implementation methods
// -------------------------------------------------------------------------
/**
@ -1132,52 +1181,13 @@ public class BrokerService implements Service, Serializable {
connector.start();
}
public boolean isDeleteAllMessagesOnStartup() {
return deleteAllMessagesOnStartup;
}
/**
* Sets whether or not all messages are deleted on startup - mostly only
* useful for testing.
* Perform any custom dependency injection
*/
public void setDeleteAllMessagesOnStartup(boolean deletePersistentMessagesOnStartup) {
this.deleteAllMessagesOnStartup = deletePersistentMessagesOnStartup;
}
public URI getVmConnectorURI() {
if (vmConnectorURI == null) {
try {
vmConnectorURI = new URI("vm://" + getBrokerName());
}
catch (URISyntaxException e) {
}
protected void configureService(Object service) {
if (service instanceof BrokerServiceAware) {
BrokerServiceAware serviceAware = (BrokerServiceAware) service;
serviceAware.setBrokerService(this);
}
return vmConnectorURI;
}
public void setVmConnectorURI(URI vmConnectorURI) {
this.vmConnectorURI = vmConnectorURI;
}
/**
* @return Returns the shutdownOnMasterFailure.
*/
public boolean isShutdownOnMasterFailure(){
return shutdownOnMasterFailure;
}
/**
* @param shutdownOnMasterFailure The shutdownOnMasterFailure to set.
*/
public void setShutdownOnMasterFailure(boolean shutdownOnMasterFailure){
this.shutdownOnMasterFailure=shutdownOnMasterFailure;
}
public boolean isKeepDurableSubsActive() {
return keepDurableSubsActive;
}
public void setKeepDurableSubsActive(boolean keepDurableSubsActive) {
this.keepDurableSubsActive = keepDurableSubsActive;
}
}

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@ -0,0 +1,27 @@
/*
* Copyright 2005-2006 The Apache Software Foundation.
*
* 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 org.apache.activemq.broker;
/**
* An interface used to represent a component that wants the {@link BrokerService}
* to be injected
*
* @version $Revision: $
*/
public interface BrokerServiceAware {
public void setBrokerService(BrokerService brokerService);
}

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@ -0,0 +1,33 @@
/*
* Copyright 2005-2006 The Apache Software Foundation.
*
* 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 org.apache.activemq.store.jdbc;
import org.apache.activemq.Service;
/**
* Represents some kind of lock service to ensure that a broker is the only master
*
* @version $Revision: $
*/
public interface DatabaseLocker extends Service {
/**
* Used by a timer to keep alive the lock.
* If the method returns false the broker should be terminated
*/
public boolean keepAlive();
}

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@ -0,0 +1,92 @@
/*
* Copyright 2005-2006 The Apache Software Foundation.
*
* 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 org.apache.activemq.store.jdbc;
import org.apache.activemq.Service;
import org.apache.activemq.broker.BrokerService;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
/**
* Represents an exclusive lock on a database to avoid multiple brokers
* running against the same logical database.
*
* @version $Revision: $
*/
public class DefaultDatabaseLocker implements DatabaseLocker {
private static final Log log = LogFactory.getLog(DefaultDatabaseLocker.class);
private final DataSource dataSource;
private final Statements statements;
private long sleepTime = 1000;
private Connection connection;
public DefaultDatabaseLocker(DataSource dataSource, Statements statements) {
this.dataSource = dataSource;
this.statements = statements;
}
public void start() throws Exception {
log.debug("Attempting to acquire exclusive lock on the database");
connection = dataSource.getConnection();
connection.setAutoCommit(false);
PreparedStatement statement = connection.prepareStatement(statements.getLockCreateStatement());
while (true) {
try {
boolean answer = statement.execute();
if (answer) {
break;
}
}
catch (Exception e) {
log.error("Failed to acquire lock: " + e, e);
}
log.info("Sleeping for " + sleepTime + " milli(s) before trying again to get the lock...");
Thread.sleep(sleepTime);
}
log.info("Becoming the master on dataSource: " + dataSource);
}
public void stop() throws Exception {
if (connection != null) {
connection.close();
}
}
public boolean keepAlive() {
try {
PreparedStatement statement = connection.prepareStatement(statements.getLockUpdateStatement());
statement.setLong(1, System.currentTimeMillis());
int rows = statement.executeUpdate();
if (rows == 1) {
return true;
}
}
catch (Exception e) {
log.error("Failed to update database lock: " + e, e);
}
return false;
}
}

View File

@ -16,15 +16,15 @@
*/
package org.apache.activemq.store.jdbc;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collections;
import java.util.Set;
import javax.sql.DataSource;
import edu.emory.mathcs.backport.java.util.concurrent.ScheduledFuture;
import edu.emory.mathcs.backport.java.util.concurrent.ScheduledThreadPoolExecutor;
import edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory;
import edu.emory.mathcs.backport.java.util.concurrent.TimeUnit;
import org.apache.activeio.command.WireFormat;
import org.apache.activeio.util.FactoryFinder;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.BrokerServiceAware;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.command.ActiveMQQueue;
import org.apache.activemq.command.ActiveMQTopic;
@ -40,10 +40,12 @@ import org.apache.activemq.util.IOExceptionSupport;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import edu.emory.mathcs.backport.java.util.concurrent.ScheduledFuture;
import edu.emory.mathcs.backport.java.util.concurrent.ScheduledThreadPoolExecutor;
import edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory;
import edu.emory.mathcs.backport.java.util.concurrent.TimeUnit;
import javax.sql.DataSource;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collections;
import java.util.Set;
/**
* A {@link PersistenceAdapter} implementation using JDBC for persistence
@ -57,19 +59,23 @@ import edu.emory.mathcs.backport.java.util.concurrent.TimeUnit;
*
* @version $Revision: 1.9 $
*/
public class JDBCPersistenceAdapter extends DataSourceSupport implements PersistenceAdapter {
public class JDBCPersistenceAdapter extends DataSourceSupport implements PersistenceAdapter, BrokerServiceAware {
private static final Log log = LogFactory.getLog(JDBCPersistenceAdapter.class);
private static FactoryFinder factoryFinder = new FactoryFinder("META-INF/services/org/apache/activemq/store/jdbc/");
private WireFormat wireFormat = new OpenWireFormat();
private BrokerService brokerService;
private Statements statements;
private JDBCAdapter adapter;
private MemoryTransactionStore transactionStore;
private ScheduledThreadPoolExecutor clockDaemon;
private ScheduledFuture clockTicket;
int cleanupPeriod = 1000 * 60 * 5;
private int cleanupPeriod = 1000 * 60 * 5;
private boolean useExternalMessageReferences;
private boolean useDatabaseLock = true;
private int lockKeepAlivePeriod = 0;
private DatabaseLocker databaseLocker;
public JDBCPersistenceAdapter() {
}
@ -156,6 +162,16 @@ public class JDBCPersistenceAdapter extends DataSourceSupport implements Persist
} finally {
transactionContext.commit();
}
if (isUseDatabaseLock()) {
DatabaseLocker service = getDatabaseLocker();
if (service == null) {
log.warn("No databaseLocker configured for the JDBC Persistence Adapter");
}
else {
service.start();
}
}
cleanup();
@ -175,6 +191,10 @@ public class JDBCPersistenceAdapter extends DataSourceSupport implements Persist
clockTicket = null;
clockDaemon.shutdown();
}
DatabaseLocker service = getDatabaseLocker();
if (service != null) {
service.stop();
}
}
public void cleanup() {
@ -227,6 +247,36 @@ public class JDBCPersistenceAdapter extends DataSourceSupport implements Persist
return adapter;
}
public DatabaseLocker getDatabaseLocker() throws IOException {
if (databaseLocker == null) {
databaseLocker = createDatabaseLocker();
if (lockKeepAlivePeriod > 0) {
getScheduledThreadPoolExecutor().scheduleAtFixedRate(new Runnable() {
public void run() {
databaseLockKeepAlive();
}
}, lockKeepAlivePeriod, lockKeepAlivePeriod, TimeUnit.MILLISECONDS);
}
}
return databaseLocker;
}
/**
* Sets the database locker strategy to use to lock the database on startup
*/
public void setDatabaseLocker(DatabaseLocker databaseLocker) {
this.databaseLocker = databaseLocker;
}
public BrokerService getBrokerService() {
return brokerService;
}
public void setBrokerService(BrokerService brokerService) {
this.brokerService = brokerService;
}
/**
* @throws IOException
*/
@ -342,6 +392,15 @@ public class JDBCPersistenceAdapter extends DataSourceSupport implements Persist
this.useExternalMessageReferences = useExternalMessageReferences;
}
public boolean isUseDatabaseLock() {
return useDatabaseLock;
}
public void setUseDatabaseLock(boolean useDatabaseLock) {
this.useDatabaseLock = useDatabaseLock;
}
static public void log(String msg, SQLException e) {
String s = msg+e.getMessage();
while( e.getNextException() != null ) {
@ -368,4 +427,37 @@ public class JDBCPersistenceAdapter extends DataSourceSupport implements Persist
public void setUsageManager(UsageManager usageManager) {
}
protected void databaseLockKeepAlive() {
boolean stop = false;
try {
DatabaseLocker locker = getDatabaseLocker();
if (locker != null) {
if (!locker.keepAlive()) {
stop = true;
}
}
}
catch (IOException e) {
log.error("Failed to get database when trying keepalive: " + e, e);
}
if (stop) {
stopBroker();
}
}
protected void stopBroker() {
// we can no longer keep the lock so lets fail
log.info("No longer able to keep the exclusive lock so giving up being a master");
try {
brokerService.stop();
}
catch (Exception e) {
log.warn("Failed to stop broker");
}
}
protected DatabaseLocker createDatabaseLocker() throws IOException {
return new DefaultDatabaseLocker(getDataSource(), getStatements());
}
}

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@ -27,6 +27,7 @@ public class Statements {
private String tablePrefix = "";
protected String messageTableName = "ACTIVEMQ_MSGS";
protected String durableSubAcksTableName = "ACTIVEMQ_ACKS";
protected String lockTableName = "ACTIVEMQ_LOCK";
protected String binaryDataType = "BLOB";
protected String containerNameDataType = "VARCHAR(250)";
@ -57,6 +58,9 @@ public class Statements {
private String deleteOldMessagesStatement;
private String[] createSchemaStatements;
private String[] dropSchemaStatements;
private String lockCreateStatement;
private String lockUpdateStatement;
private boolean useLockCreateWhereClause;
public String[] getCreateSchemaStatements() {
if (createSchemaStatements == null) {
@ -75,7 +79,11 @@ public class Statements {
"CREATE TABLE " + getFullAckTableName() + "(" + "CONTAINER " + containerNameDataType + " NOT NULL"
+ ", CLIENT_ID " + stringIdDataType + " NOT NULL" + ", SUB_NAME " + stringIdDataType
+ " NOT NULL" + ", SELECTOR " + stringIdDataType + ", LAST_ACKED_ID " + sequenceDataType
+ ", PRIMARY KEY ( CONTAINER, CLIENT_ID, SUB_NAME))", };
+ ", PRIMARY KEY ( CONTAINER, CLIENT_ID, SUB_NAME))",
"CREATE TABLE " + getFullLockTableName() + "( ID " + longDataType + ", TIME " + longDataType
+ ", BROKER_NAME " + stringIdDataType + ", PRIMARY KEY (ID) )",
"INSERT INTO " + getFullLockTableName() + "(ID) VALUES (1)",
};
}
return createSchemaStatements;
}
@ -220,12 +228,30 @@ public class Statements {
public String getDeleteOldMessagesStatement() {
if (deleteOldMessagesStatement == null) {
deleteOldMessagesStatement = "DELETE FROM " + getFullMessageTableName()
+ " WHERE ( EXPIRATION<>0 AND EXPIRATION<?) OR ID <= " + "( SELECT min(" + getFullAckTableName()
+ ".LAST_ACKED_ID) " + "FROM " + getFullAckTableName() + " WHERE " + getFullAckTableName()
+ ".CONTAINER=" + getFullMessageTableName() + ".CONTAINER)";
+ " WHERE ( EXPIRATION<>0 AND EXPIRATION<?) OR ID <= " + "( SELECT min(" + getFullAckTableName()
+ ".LAST_ACKED_ID) " + "FROM " + getFullAckTableName() + " WHERE " + getFullAckTableName()
+ ".CONTAINER=" + getFullMessageTableName() + ".CONTAINER)";
}
return deleteOldMessagesStatement;
}
public String getLockCreateStatement() {
if (lockCreateStatement == null) {
lockCreateStatement = "SELECT * FROM " + getFullLockTableName();
if (useLockCreateWhereClause) {
lockCreateStatement += " WHERE ID = 1";
}
lockCreateStatement += " FOR UPDATE";
}
return lockCreateStatement;
}
public String getLockUpdateStatement() {
if (lockUpdateStatement == null) {
lockUpdateStatement = "UPDATE " + getFullLockTableName() + " SET time = ? WHERE ID = 1";
}
return lockUpdateStatement;
}
public String getFullMessageTableName() {
return getTablePrefix() + getMessageTableName();
@ -234,7 +260,12 @@ public class Statements {
public String getFullAckTableName() {
return getTablePrefix() + getDurableSubAcksTableName();
}
public String getFullLockTableName() {
return getTablePrefix() + getLockTableName();
}
/**
* @return Returns the containerNameDataType.
*/
@ -339,6 +370,14 @@ public class Statements {
public void setDurableSubAcksTableName(String durableSubAcksTableName) {
this.durableSubAcksTableName = durableSubAcksTableName;
}
public String getLockTableName() {
return lockTableName;
}
public void setLockTableName(String lockTableName) {
this.lockTableName = lockTableName;
}
public String getLongDataType() {
return longDataType;
@ -444,4 +483,19 @@ public class Statements {
this.updateMessageStatement = updateMessageStatment;
}
public boolean isUseLockCreateWhereClause() {
return useLockCreateWhereClause;
}
public void setUseLockCreateWhereClause(boolean useLockCreateWhereClause) {
this.useLockCreateWhereClause = useLockCreateWhereClause;
}
public void setLockCreateStatement(String lockCreateStatement) {
this.lockCreateStatement = lockCreateStatement;
}
public void setLockUpdateStatement(String lockUpdateStatement) {
this.lockUpdateStatement = lockUpdateStatement;
}
}