org.jgroups.blocks

Class ConnectionTable

Implemented Interfaces:
Runnable
Known Direct Subclasses:
ConnectionTableNIO

public class ConnectionTable
extends java.lang.Object
implements Runnable

Manages incoming and outgoing TCP connections. For each outgoing message to destination P, if there is not yet a connection for P, one will be created. Subsequent outgoing messages will use this connection. For incoming messages, one server socket is created at startup. For each new incoming client connecting, a new thread from a thread pool is allocated and listens for incoming messages until the socket is closed by the peer.
Sockets/threads with no activity will be killed after some time.

Incoming messages from any of the sockets can be received by setting the message listener.

Author:
Bela Ban

Nested Class Summary

static interface
ConnectionTable.ConnectionListener
Used to be notified about connection establishment and teardown.
static interface
ConnectionTable.Receiver
Used for message reception.

Field Summary

protected Log
log

Constructor Summary

ConnectionTable(InetAddress bind_addr, int srv_port)
ConnectionTable(int srv_port)
Regular ConnectionTable without expiration of idle connections
ConnectionTable(int srv_port, long reaper_interval, long conn_expire_time)
ConnectionTable including a connection reaper.
ConnectionTable(ConnectionTable.Receiver r, InetAddress bind_addr, InetAddress external_addr, int srv_port, int max_port)
Create a ConnectionTable
ConnectionTable(ConnectionTable.Receiver r, InetAddress bind_addr, InetAddress external_addr, int srv_port, int max_port, long reaper_interval, long conn_expire_time)
ConnectionTable including a connection reaper.

Method Summary

void
addConnectionListener(ConnectionTable.ConnectionListener l)
protected ServerSocket
createServerSocket(int start_port, int end_port)
Finds first available port starting at start_port and returns server socket.
Address
getLocalAddress()
int
getNumConnections()
int
getReceiveBufferSize()
int
getSendBufferSize()
int
getSocketConnectionTimeout()
boolean
getUseSendQueues()
protected void
init()
void
receive(Address sender, byte[] data, int offset, int length)
Calls the receiver callback.
void
remove(Address addr)
Remove addrfrom connection table.
void
removeConnectionListener(ConnectionTable.ConnectionListener l)
void
run()
Acceptor thread.
void
send(Address dest, byte[] data, int offset, int length)
void
setReceiveBufferSize(int recv_buf_size)
void
setReceiver(ConnectionTable.Receiver r)
void
setSendBufferSize(int send_buf_size)
void
setSocketConnectionTimeout(int sock_conn_timeout)
void
setUseSendQueues(boolean flag)
void
start()
void
stop()
Closes all open sockets, the server socket and all threads waiting for incoming messages
String
toString()

Field Details

log

protected final Log log

Constructor Details

ConnectionTable

public ConnectionTable(InetAddress bind_addr,
                       int srv_port)
            throws Exception

ConnectionTable

public ConnectionTable(int srv_port)
            throws Exception
Regular ConnectionTable without expiration of idle connections
Parameters:
srv_port - The port on which the server will listen. If this port is reserved, the next free port will be taken (incrementing srv_port).

ConnectionTable

public ConnectionTable(int srv_port,
                       long reaper_interval,
                       long conn_expire_time)
            throws Exception
ConnectionTable including a connection reaper. Connections that have been idle for more than conn_expire_time milliseconds will be closed and removed from the connection table. On next access they will be re-created.
Parameters:
srv_port - The port on which the server will listen
reaper_interval - Number of milliseconds to wait for reaper between attepts to reap idle connections
conn_expire_time - Number of milliseconds a connection can be idle (no traffic sent or received until it will be reaped

ConnectionTable

public ConnectionTable(ConnectionTable.Receiver r,
                       InetAddress bind_addr,
                       InetAddress external_addr,
                       int srv_port,
                       int max_port)
            throws Exception
Create a ConnectionTable
Parameters:
r - A reference to a receiver of all messages received by this class. Method receive() will be called.
bind_addr - The host name or IP address of the interface to which the server socket will bind. This is interesting only in multi-homed systems. If bind_addr is null, the server socket will bind to the first available interface (e.g. /dev/hme0 on Solaris or /dev/eth0 on Linux systems).
external_addr - The address which will be broadcast to the group (the externally visible address which this host should be contacted on). If external_addr is null, it will default to the same address that the server socket is bound to.
srv_port - The port to which the server socket will bind to. If this port is reserved, the next free port will be taken (incrementing srv_port).
max_port - The largest port number that the server socket will be bound to. If max_port <32srv_port then there is no limit.

ConnectionTable

public ConnectionTable(ConnectionTable.Receiver r,
                       InetAddress bind_addr,
                       InetAddress external_addr,
                       int srv_port,
                       int max_port,
                       long reaper_interval,
                       long conn_expire_time)
            throws Exception
ConnectionTable including a connection reaper. Connections that have been idle for more than conn_expire_time milliseconds will be closed and removed from the connection table. On next access they will be re-created.
Parameters:
r - The Receiver
bind_addr - The host name or IP address of the interface to which the server socket will bind. This is interesting only in multi-homed systems. If bind_addr is null, the server socket will bind to the first available interface (e.g. /dev/hme0 on Solaris or /dev/eth0 on Linux systems).
external_addr - The address which will be broadcast to the group (the externally visible address which this host should be contacted on). If external_addr is null, it will default to the same address that the server socket is bound to.
srv_port - The port to which the server socket will bind to. If this port is reserved, the next free port will be taken (incrementing srv_port).
max_port - The largest port number that the server socket will be bound to. If max_port <32srv_port then there is no limit.
reaper_interval - Number of milliseconds to wait for reaper between attepts to reap idle connections
conn_expire_time - Number of milliseconds a connection can be idle (no traffic sent or received until it will be reaped

Method Details

addConnectionListener

public void addConnectionListener(ConnectionTable.ConnectionListener l)

createServerSocket

protected ServerSocket createServerSocket(int start_port,
                                          int end_port)
            throws Exception
Finds first available port starting at start_port and returns server socket. Will not bind to port >end_port. Sets srv_port

getLocalAddress

public Address getLocalAddress()

getNumConnections

public int getNumConnections()

getReceiveBufferSize

public int getReceiveBufferSize()

getSendBufferSize

public int getSendBufferSize()

getSocketConnectionTimeout

public int getSocketConnectionTimeout()

getUseSendQueues

public boolean getUseSendQueues()

init

protected void init()
            throws Exception

receive

public void receive(Address sender,
                    byte[] data,
                    int offset,
                    int length)
Calls the receiver callback. We serialize access to this method because it may be called concurrently by several Connection handler threads. Therefore the receiver doesn't need to synchronize.

remove

public void remove(Address addr)
Remove addrfrom connection table. This is typically triggered when a member is suspected.

removeConnectionListener

public void removeConnectionListener(ConnectionTable.ConnectionListener l)

run

public void run()
Acceptor thread. Continuously accept new connections. Create a new thread for each new connection and put it in conns. When the thread should stop, it is interrupted by the thread creator.

send

public void send(Address dest,
                 byte[] data,
                 int offset,
                 int length)
            throws Exception

setReceiveBufferSize

public void setReceiveBufferSize(int recv_buf_size)

setReceiver

public void setReceiver(ConnectionTable.Receiver r)

setSendBufferSize

public void setSendBufferSize(int send_buf_size)

setSocketConnectionTimeout

public void setSocketConnectionTimeout(int sock_conn_timeout)

setUseSendQueues

public void setUseSendQueues(boolean flag)

start

public void start()
            throws Exception

stop

public void stop()
Closes all open sockets, the server socket and all threads waiting for incoming messages

toString

public String toString()

Copyright B) 1998-2005 Bela Ban. All Rights Reserved.