org.apache.catalina.tribes.membership

Class McastServiceImpl

java.lang.Object

org.apache.catalina.tribes.membership.McastServiceImpl

public class McastServiceImpl
extends Object

A membership implementation using simple multicast. This is the representation of a multicast membership service. This class is responsible for maintaining a list of active cluster nodes in the cluster. If a node fails to send out a heartbeat, the node will be dismissed. This is the low level implementation that handles the multicasting sockets. Need to fix this, could use java.nio and only need one thread to send and receive, or just use a timeout on the receive

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	McastServiceImpl.ReceiverThread
protected static class	McastServiceImpl.RecoveryThread
class	McastServiceImpl.SenderThread

Field Summary

Fields

Modifier and Type	Field and Description
protected InetAddress	address The multicast address
protected boolean	doRunReceiver
protected boolean	doRunSender Internal flag used for the listen thread that listens to the multicasting socket.
protected ExecutorService	executor Dont interrupt the sender/receiver thread, but pass off to an executor
protected Object	expiredMutex
protected boolean	localLoopbackDisabled disable/enable local loopback message
protected static int	MAX_PACKET_SIZE
protected InetAddress	mcastBindAddress bind address
protected int	mcastSoTimeout Read timeout on the mcast socket
protected int	mcastTTL Time to live for the multicast packets that are being sent out
protected MemberImpl	member The local member that we intend to broad cast over and over again
protected Membership	membership The membership, used so that we calculate memberships when they arrive or don't arrive
protected MessageListener	msgservice The actual listener for broadcast callbacks
protected int	port The multicast port
protected DatagramPacket	receivePacket Reuse the receivePacket, no need to create a new one everytime
protected McastServiceImpl.ReceiverThread	receiver Thread to listen for pings
protected int	recoveryCounter nr of times the system has to fail before a recovery is initiated
protected boolean	recoveryEnabled Add the ability to turn on/off recovery
protected long	recoverySleepTime The time the recovery thread sleeps between recovery attempts
protected McastServiceImpl.SenderThread	sender Thread to send pings
protected long	sendFrequency How often to we send out a broadcast saying we are alive, must be smaller than timeToExpiration
protected DatagramPacket	sendPacket Reuse the sendPacket, no need to create a new one everytime
protected MembershipListener	service The actual listener, for callback when stuff goes down
protected static StringManager	sm
protected MulticastSocket	socket Socket that we intend to listen to
protected int	startLevel
protected long	timeToExpiration The time it takes for a member to expire.

Constructor Summary

Constructors

Constructor and Description
McastServiceImpl(MemberImpl member, long sendFrequency, long expireTime, int port, InetAddress bind, InetAddress mcastAddress, int ttl, int soTimeout, MembershipListener service, MessageListener msgservice, boolean localLoopbackDisabled) Create a new mcast service instance.

Method Summary

Modifier and Type	Method and Description
protected void	checkExpired()
Channel	getChannel()
int	getRecoveryCounter()
long	getRecoverySleepTime()
long	getServiceStartTime()
void	init()
boolean	isRecoveryEnabled()
void	receive() Receive a datagram packet, locking wait
void	send(boolean checkexpired) Send a ping.
void	send(boolean checkexpired, DatagramPacket packet)
void	setChannel(Channel channel)
void	setRecoveryCounter(int recoveryCounter)
void	setRecoveryEnabled(boolean recoveryEnabled)
void	setRecoverySleepTime(long recoverySleepTime)
protected void	setupSocket()
void	start(int level) Start the service
boolean	stop(int level) Stops the service.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_PACKET_SIZE

protected static final int MAX_PACKET_SIZE

See Also:

Constant Field Values

sm

protected static final StringManager sm

doRunSender

protected volatile boolean doRunSender

Internal flag used for the listen thread that listens to the multicasting socket.

doRunReceiver

protected volatile boolean doRunReceiver

startLevel

protected int startLevel

socket

protected MulticastSocket socket

Socket that we intend to listen to

member

protected final MemberImpl member

The local member that we intend to broad cast over and over again

address

protected final InetAddress address

The multicast address

port

protected final int port

The multicast port

timeToExpiration

protected final long timeToExpiration

The time it takes for a member to expire.

sendFrequency

protected final long sendFrequency

How often to we send out a broadcast saying we are alive, must be smaller than timeToExpiration

sendPacket

protected DatagramPacket sendPacket

Reuse the sendPacket, no need to create a new one everytime

receivePacket

protected DatagramPacket receivePacket

Reuse the receivePacket, no need to create a new one everytime

membership

protected Membership membership

The membership, used so that we calculate memberships when they arrive or don't arrive

service

protected final MembershipListener service

The actual listener, for callback when stuff goes down

msgservice

protected final MessageListener msgservice

The actual listener for broadcast callbacks

receiver

protected McastServiceImpl.ReceiverThread receiver

Thread to listen for pings

sender

protected McastServiceImpl.SenderThread sender

Thread to send pings

mcastTTL

protected final int mcastTTL

Time to live for the multicast packets that are being sent out

mcastSoTimeout

protected int mcastSoTimeout

Read timeout on the mcast socket

mcastBindAddress

protected final InetAddress mcastBindAddress

bind address

recoveryCounter

protected int recoveryCounter

nr of times the system has to fail before a recovery is initiated

recoverySleepTime

protected long recoverySleepTime

The time the recovery thread sleeps between recovery attempts

recoveryEnabled

protected boolean recoveryEnabled

Add the ability to turn on/off recovery

executor

protected final ExecutorService executor

Dont interrupt the sender/receiver thread, but pass off to an executor

localLoopbackDisabled

protected final boolean localLoopbackDisabled

disable/enable local loopback message

expiredMutex

protected final Object expiredMutex

Constructor Detail

McastServiceImpl

public McastServiceImpl(MemberImpl member,
                        long sendFrequency,
                        long expireTime,
                        int port,
                        InetAddress bind,
                        InetAddress mcastAddress,
                        int ttl,
                        int soTimeout,
                        MembershipListener service,
                        MessageListener msgservice,
                        boolean localLoopbackDisabled)
                 throws IOException

Create a new mcast service instance.

Parameters:

member - - the local member

sendFrequency - - the time (ms) in between pings sent out

expireTime - - the time (ms) for a member to expire

port - - the mcast port

bind - - the bind address (not sure this is used yet)

mcastAddress - - the mcast address

ttl - multicast ttl that will be set on the socket

soTimeout - Socket timeout

service - - the callback service

msgservice - Message listener

localLoopbackDisabled - - disable loopbackMode

Throws:

IOException - Init error

Method Detail

init

public void init()
          throws IOException

Throws:

IOException

setupSocket

protected void setupSocket()
                    throws IOException

Throws:

IOException

start

public void start(int level)
           throws IOException

Start the service

Parameters:

level - 1 starts the receiver, level 2 starts the sender

Throws:

IOException - if the service fails to start

IllegalStateException - if the service is already started

stop

public boolean stop(int level)
             throws IOException

Stops the service.

Parameters:

level - Stop status

Returns:

true if the stop is complete

Throws:

IOException - if the service fails to disconnect from the sockets

receive

public void receive()
             throws IOException

Receive a datagram packet, locking wait

Throws:

IOException - Received failed

checkExpired

protected void checkExpired()

send

public void send(boolean checkexpired)
          throws IOException

Send a ping.

Parameters:

checkexpired - true to check for expiration

Throws:

IOException - Send error

send

public void send(boolean checkexpired,
                 DatagramPacket packet)
          throws IOException

Throws:

IOException

getServiceStartTime

public long getServiceStartTime()

getRecoveryCounter

public int getRecoveryCounter()

isRecoveryEnabled

public boolean isRecoveryEnabled()

getRecoverySleepTime

public long getRecoverySleepTime()

getChannel

public Channel getChannel()

setChannel

public void setChannel(Channel channel)

setRecoveryCounter

public void setRecoveryCounter(int recoveryCounter)

setRecoveryEnabled

public void setRecoveryEnabled(boolean recoveryEnabled)

setRecoverySleepTime

public void setRecoverySleepTime(long recoverySleepTime)