// ========================================================================
// Copyright (c) 2008-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
package org.eclipse.jetty.server.session;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask;
import javax.naming.InitialContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.sql.DataSource;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.SessionManager;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.util.log.Logger;
/**
* JDBCSessionIdManager
*
* SessionIdManager implementation that uses a database to store in-use session ids,
* to support distributed sessions.
*
*/
public class JDBCSessionIdManager extends AbstractSessionIdManager
{
final static Logger LOG = SessionHandler.LOG;
protected final HashSet<String> _sessionIds = new HashSet<String>();
protected Server _server;
protected Driver _driver;
protected String _driverClassName;
protected String _connectionUrl;
protected DataSource _datasource;
protected String _jndiName;
protected String _sessionIdTable = "JettySessionIds";
protected String _sessionTable = "JettySessions";
protected String _sessionTableRowId = "rowId";
protected Timer _timer; //scavenge timer
protected TimerTask _task; //scavenge task
protected long _lastScavengeTime;
protected long _scavengeIntervalMs = 1000L * 60 * 10; //10mins
protected String _blobType; //if not set, is deduced from the type of the database at runtime
protected String _longType; //if not set, is deduced from the type of the database at runtime
protected String _createSessionIdTable;
protected String _createSessionTable;
protected String _selectExpiredSessions;
protected String _deleteOldExpiredSessions;
protected String _insertId;
protected String _deleteId;
protected String _queryId;
protected String _insertSession;
protected String _deleteSession;
protected String _selectSession;
protected String _updateSession;
protected String _updateSessionNode;
protected String _updateSessionAccessTime;
protected DatabaseAdaptor _dbAdaptor;
/**
* DatabaseAdaptor
*
* Handles differences between databases.
*
* Postgres uses the getBytes and setBinaryStream methods to access
* a "bytea" datatype, which can be up to 1Gb of binary data. MySQL
* is happy to use the "blob" type and getBlob() methods instead.
*
* TODO if the differences become more major it would be worthwhile
* refactoring this class.
*/
public class DatabaseAdaptor
{
String _dbName;
boolean _isLower;
boolean _isUpper;
public DatabaseAdaptor (DatabaseMetaData dbMeta)
throws SQLException
{
_dbName = dbMeta.getDatabaseProductName().toLowerCase();
LOG.debug ("Using database {}",_dbName);
_isLower = dbMeta.storesLowerCaseIdentifiers();
_isUpper = dbMeta.storesUpperCaseIdentifiers();
}
/**
* Convert a camel case identifier into either upper or lower
* depending on the way the db stores identifiers.
*
* @param identifier
* @return the converted identifier
*/
public String convertIdentifier (String identifier)
{
if (_isLower)
return identifier.toLowerCase();
if (_isUpper)
return identifier.toUpperCase();
return identifier;
}
public String getDBName ()
{
return _dbName;
}
public String getBlobType ()
{
if (_blobType != null)
return _blobType;
if (_dbName.startsWith("postgres"))
return "bytea";
return "blob";
}
public String getLongType ()
{
if (_longType != null)
return _longType;
if (_dbName.startsWith("oracle"))
return "number(20)";
return "bigint";
}
public InputStream getBlobInputStream (ResultSet result, String columnName)
throws SQLException
{
if (_dbName.startsWith("postgres"))
{
byte[] bytes = result.getBytes(columnName);
return new ByteArrayInputStream(bytes);
}
Blob blob = result.getBlob(columnName);
return blob.getBinaryStream();
}
/**
* rowId is a reserved word for Oracle, so change the name of this column
* @return
*/
public String getRowIdColumnName ()
{
if (_dbName != null && _dbName.startsWith("oracle"))
return "srowId";
return "rowId";
}
}
public JDBCSessionIdManager(Server server)
{
super();
_server=server;
}
public JDBCSessionIdManager(Server server, Random random)
{
super(random);
_server=server;
}
/**
* Configure jdbc connection information via a jdbc Driver
*
* @param driverClassName
* @param connectionUrl
*/
public void setDriverInfo (String driverClassName, String connectionUrl)
{
_driverClassName=driverClassName;
_connectionUrl=connectionUrl;
}
/**
* Configure jdbc connection information via a jdbc Driver
*
* @param driverClass
* @param connectionUrl
*/
public void setDriverInfo (Driver driverClass, String connectionUrl)
{
_driver=driverClass;
_connectionUrl=connectionUrl;
}
public void setDatasource (DataSource ds)
{
_datasource = ds;
}
public DataSource getDataSource ()
{
return _datasource;
}
public String getDriverClassName()
{
return _driverClassName;
}
public String getConnectionUrl ()
{
return _connectionUrl;
}
public void setDatasourceName (String jndi)
{
_jndiName=jndi;
}
public String getDatasourceName ()
{
return _jndiName;
}
public void setBlobType (String name)
{
_blobType = name;
}
public String getBlobType ()
{
return _blobType;
}
public String getLongType()
{
return _longType;
}
public void setLongType(String longType)
{
this._longType = longType;
}
public void setScavengeInterval (long sec)
{
if (sec<=0)
sec=60;
long old_period=_scavengeIntervalMs;
long period=sec*1000L;
_scavengeIntervalMs=period;
//add a bit of variability into the scavenge time so that not all
//nodes with the same scavenge time sync up
long tenPercent = _scavengeIntervalMs/10;
if ((System.currentTimeMillis()%2) == 0)
_scavengeIntervalMs += tenPercent;
if (LOG.isDebugEnabled())
LOG.debug("Scavenging every "+_scavengeIntervalMs+" ms");
if (_timer!=null && (period!=old_period || _task==null))
{
synchronized (this)
{
if (_task!=null)
_task.cancel();
_task = new TimerTask()
{
@Override
public void run()
{
scavenge();
}
};
_timer.schedule(_task,_scavengeIntervalMs,_scavengeIntervalMs);
}
}
}
public long getScavengeInterval ()
{
return _scavengeIntervalMs/1000;
}
public void addSession(HttpSession session)
{
if (session == null)
return;
synchronized (_sessionIds)
{
String id = ((JDBCSessionManager.Session)session).getClusterId();
try
{
insert(id);
_sessionIds.add(id);
}
catch (Exception e)
{
LOG.warn("Problem storing session id="+id, e);
}
}
}
public void removeSession(HttpSession session)
{
if (session == null)
return;
removeSession(((JDBCSessionManager.Session)session).getClusterId());
}
public void removeSession (String id)
{
if (id == null)
return;
synchronized (_sessionIds)
{
if (LOG.isDebugEnabled())
LOG.debug("Removing session id="+id);
try
{
_sessionIds.remove(id);
delete(id);
}
catch (Exception e)
{
LOG.warn("Problem removing session id="+id, e);
}
}
}
/**
* Get the session id without any node identifier suffix.
*
* @see org.eclipse.jetty.server.SessionIdManager#getClusterId(java.lang.String)
*/
public String getClusterId(String nodeId)
{
int dot=nodeId.lastIndexOf('.');
return (dot>0)?nodeId.substring(0,dot):nodeId;
}
/**
* Get the session id, including this node's id as a suffix.
*
* @see org.eclipse.jetty.server.SessionIdManager#getNodeId(java.lang.String, javax.servlet.http.HttpServletRequest)
*/
public String getNodeId(String clusterId, HttpServletRequest request)
{
if (_workerName!=null)
return clusterId+'.'+_workerName;
return clusterId;
}
public boolean idInUse(String id)
{
if (id == null)
return false;
String clusterId = getClusterId(id);
boolean inUse = false;
synchronized (_sessionIds)
{
inUse = _sessionIds.contains(clusterId);
}
if (inUse)
return true; //optimisation - if this session is one we've been managing, we can check locally
//otherwise, we need to go to the database to check
try
{
return exists(clusterId);
}
catch (Exception e)
{
LOG.warn("Problem checking inUse for id="+clusterId, e);
return false;
}
}
/**
* Invalidate the session matching the id on all contexts.
*
* @see org.eclipse.jetty.server.SessionIdManager#invalidateAll(java.lang.String)
*/
public void invalidateAll(String id)
{
//take the id out of the list of known sessionids for this node
removeSession(id);
synchronized (_sessionIds)
{
//tell all contexts that may have a session object with this id to
//get rid of them
Handler[] contexts = _server.getChildHandlersByClass(ContextHandler.class);
for (int i=0; contexts!=null && i<contexts.length; i++)
{
SessionHandler sessionHandler = (SessionHandler)((ContextHandler)contexts[i]).getChildHandlerByClass(SessionHandler.class);
if (sessionHandler != null)
{
SessionManager manager = sessionHandler.getSessionManager();
if (manager != null && manager instanceof JDBCSessionManager)
{
((JDBCSessionManager)manager).invalidateSession(id);
}
}
}
}
}
/**
* Start up the id manager.
*
* Makes necessary database tables and starts a Session
* scavenger thread.
*/
@Override
public void doStart()
{
try
{
initializeDatabase();
prepareTables();
super.doStart();
if (LOG.isDebugEnabled())
LOG.debug("Scavenging interval = "+getScavengeInterval()+" sec");
_timer=new Timer("JDBCSessionScavenger", true);
setScavengeInterval(getScavengeInterval());
}
catch (Exception e)
{
LOG.warn("Problem initialising JettySessionIds table", e);
}
}
/**
* Stop the scavenger.
*/
@Override
public void doStop ()
throws Exception
{
synchronized(this)
{
if (_task!=null)
_task.cancel();
if (_timer!=null)
_timer.cancel();
_timer=null;
}
super.doStop();
}
/**
* Get a connection from the driver or datasource.
*
* @return the connection for the datasource
* @throws SQLException
*/
protected Connection getConnection ()
throws SQLException
{
if (_datasource != null)
return _datasource.getConnection();
else
return DriverManager.getConnection(_connectionUrl);
}
private void initializeDatabase ()
throws Exception
{
if (_datasource != null)
return; //already set up
if (_jndiName!=null)
{
InitialContext ic = new InitialContext();
_datasource = (DataSource)ic.lookup(_jndiName);
}
else if ( _driver != null && _connectionUrl != null )
{
DriverManager.registerDriver(_driver);
}
else if (_driverClassName != null && _connectionUrl != null)
{
Class.forName(_driverClassName);
}
else
throw new IllegalStateException("No database configured for sessions");
}
/**
* Set up the tables in the database
* @throws SQLException
*/
private void prepareTables()
throws SQLException
{
_createSessionIdTable = "create table "+_sessionIdTable+" (id varchar(120), primary key(id))";
_selectExpiredSessions = "select * from "+_sessionTable+" where expiryTime >= ? and expiryTime <= ?";
_deleteOldExpiredSessions = "delete from "+_sessionTable+" where expiryTime >0 and expiryTime <= ?";
_insertId = "insert into "+_sessionIdTable+" (id) values (?)";
_deleteId = "delete from "+_sessionIdTable+" where id = ?";
_queryId = "select * from "+_sessionIdTable+" where id = ?";
Connection connection = null;
try
{
//make the id table
connection = getConnection();
connection.setAutoCommit(true);
DatabaseMetaData metaData = connection.getMetaData();
_dbAdaptor = new DatabaseAdaptor(metaData);
_sessionTableRowId = _dbAdaptor.getRowIdColumnName();
//checking for table existence is case-sensitive, but table creation is not
String tableName = _dbAdaptor.convertIdentifier(_sessionIdTable);
ResultSet result = metaData.getTables(null, null, tableName, null);
if (!result.next())
{
//table does not exist, so create it
connection.createStatement().executeUpdate(_createSessionIdTable);
}
//make the session table if necessary
tableName = _dbAdaptor.convertIdentifier(_sessionTable);
result = metaData.getTables(null, null, tableName, null);
if (!result.next())
{
//table does not exist, so create it
String blobType = _dbAdaptor.getBlobType();
String longType = _dbAdaptor.getLongType();
_createSessionTable = "create table "+_sessionTable+" ("+_sessionTableRowId+" varchar(120), sessionId varchar(120), "+
" contextPath varchar(60), virtualHost varchar(60), lastNode varchar(60), accessTime "+longType+", "+
" lastAccessTime "+longType+", createTime "+longType+", cookieTime "+longType+", "+
" lastSavedTime "+longType+", expiryTime "+longType+", map "+blobType+", primary key("+_sessionTableRowId+"))";
connection.createStatement().executeUpdate(_createSessionTable);
}
//make some indexes on the JettySessions table
String index1 = "idx_"+_sessionTable+"_expiry";
String index2 = "idx_"+_sessionTable+"_session";
result = metaData.getIndexInfo(null, null, tableName, false, false);
boolean index1Exists = false;
boolean index2Exists = false;
while (result.next())
{
String idxName = result.getString("INDEX_NAME");
if (index1.equalsIgnoreCase(idxName))
index1Exists = true;
else if (index2.equalsIgnoreCase(idxName))
index2Exists = true;
}
if (!(index1Exists && index2Exists))
{
Statement statement = connection.createStatement();
if (!index1Exists)
statement.executeUpdate("create index "+index1+" on "+_sessionTable+" (expiryTime)");
if (!index2Exists)
statement.executeUpdate("create index "+index2+" on "+_sessionTable+" (sessionId, contextPath)");
}
//set up some strings representing the statements for session manipulation
_insertSession = "insert into "+_sessionTable+
" ("+_sessionTableRowId+", sessionId, contextPath, virtualHost, lastNode, accessTime, lastAccessTime, createTime, cookieTime, lastSavedTime, expiryTime, map) "+
" values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
_deleteSession = "delete from "+_sessionTable+
" where "+_sessionTableRowId+" = ?";
_selectSession = "select * from "+_sessionTable+
" where sessionId = ? and contextPath = ? and virtualHost = ?";
_updateSession = "update "+_sessionTable+
" set lastNode = ?, accessTime = ?, lastAccessTime = ?, lastSavedTime = ?, expiryTime = ?, map = ? where "+_sessionTableRowId+" = ?";
_updateSessionNode = "update "+_sessionTable+
" set lastNode = ? where "+_sessionTableRowId+" = ?";
_updateSessionAccessTime = "update "+_sessionTable+
" set lastNode = ?, accessTime = ?, lastAccessTime = ?, lastSavedTime = ?, expiryTime = ? where "+_sessionTableRowId+" = ?";
}
finally
{
if (connection != null)
connection.close();
}
}
/**
* Insert a new used session id into the table.
*
* @param id
* @throws SQLException
*/
private void insert (String id)
throws SQLException
{
Connection connection = null;
try
{
connection = getConnection();
connection.setAutoCommit(true);
PreparedStatement query = connection.prepareStatement(_queryId);
query.setString(1, id);
ResultSet result = query.executeQuery();
//only insert the id if it isn't in the db already
if (!result.next())
{
PreparedStatement statement = connection.prepareStatement(_insertId);
statement.setString(1, id);
statement.executeUpdate();
}
}
finally
{
if (connection != null)
connection.close();
}
}
/**
* Remove a session id from the table.
*
* @param id
* @throws SQLException
*/
private void delete (String id)
throws SQLException
{
Connection connection = null;
try
{
connection = getConnection();
connection.setAutoCommit(true);
PreparedStatement statement = connection.prepareStatement(_deleteId);
statement.setString(1, id);
statement.executeUpdate();
}
finally
{
if (connection != null)
connection.close();
}
}
/**
* Check if a session id exists.
*
* @param id
* @return
* @throws SQLException
*/
private boolean exists (String id)
throws SQLException
{
Connection connection = null;
try
{
connection = getConnection();
connection.setAutoCommit(true);
PreparedStatement statement = connection.prepareStatement(_queryId);
statement.setString(1, id);
ResultSet result = statement.executeQuery();
return result.next();
}
finally
{
if (connection != null)
connection.close();
}
}
/**
* Look for sessions in the database that have expired.
*
* We do this in the SessionIdManager and not the SessionManager so
* that we only have 1 scavenger, otherwise if there are n SessionManagers
* there would be n scavengers, all contending for the database.
*
* We look first for sessions that expired in the previous interval, then
* for sessions that expired previously - these are old sessions that no
* node is managing any more and have become stuck in the database.
*/
private void scavenge ()
{
Connection connection = null;
List<String> expiredSessionIds = new ArrayList<String>();
try
{
if (LOG.isDebugEnabled())
LOG.debug("Scavenge sweep started at "+System.currentTimeMillis());
if (_lastScavengeTime > 0)
{
connection = getConnection();
connection.setAutoCommit(true);
//"select sessionId from JettySessions where expiryTime > (lastScavengeTime - scanInterval) and expiryTime < lastScavengeTime";
PreparedStatement statement = connection.prepareStatement(_selectExpiredSessions);
long lowerBound = (_lastScavengeTime - _scavengeIntervalMs);
long upperBound = _lastScavengeTime;
if (LOG.isDebugEnabled())
LOG.debug (" Searching for sessions expired between "+lowerBound + " and "+upperBound);
statement.setLong(1, lowerBound);
statement.setLong(2, upperBound);
ResultSet result = statement.executeQuery();
while (result.next())
{
String sessionId = result.getString("sessionId");
expiredSessionIds.add(sessionId);
if (LOG.isDebugEnabled()) LOG.debug (" Found expired sessionId="+sessionId);
}
//tell the SessionManagers to expire any sessions with a matching sessionId in memory
Handler[] contexts = _server.getChildHandlersByClass(ContextHandler.class);
for (int i=0; contexts!=null && i<contexts.length; i++)
{
SessionHandler sessionHandler = (SessionHandler)((ContextHandler)contexts[i]).getChildHandlerByClass(SessionHandler.class);
if (sessionHandler != null)
{
SessionManager manager = sessionHandler.getSessionManager();
if (manager != null && manager instanceof JDBCSessionManager)
{
((JDBCSessionManager)manager).expire(expiredSessionIds);
}
}
}
//find all sessions that have expired at least a couple of scanIntervals ago and just delete them
upperBound = _lastScavengeTime - (2 * _scavengeIntervalMs);
if (upperBound > 0)
{
if (LOG.isDebugEnabled()) LOG.debug("Deleting old expired sessions expired before "+upperBound);
statement = connection.prepareStatement(_deleteOldExpiredSessions);
statement.setLong(1, upperBound);
statement.executeUpdate();
}
}
}
catch (Exception e)
{
if (isRunning())
LOG.warn("Problem selecting expired sessions", e);
else
LOG.ignore(e);
}
finally
{
_lastScavengeTime=System.currentTimeMillis();
if (LOG.isDebugEnabled()) LOG.debug("Scavenge sweep ended at "+_lastScavengeTime);
if (connection != null)
{
try
{
connection.close();
}
catch (SQLException e)
{
LOG.warn(e);
}
}
}
}
}