McastServiceImpl (Apache Tomcat 8.0.53 API Documentation)

java.lang.Object
- org.apache.catalina.tribes.membership.McastServiceImpl

```
public class McastServiceImpl
extends java.lang.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 java.net.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 java.util.concurrent.ExecutorService`	`executor` Dont interrupt the sender/receiver thread, but pass off to an executor
`protected java.lang.Object`	`expiredMutex`
`protected boolean`	`localLoopbackDisabled` disable/enable local loopback message
`protected static int`	`MAX_PACKET_SIZE`
`protected java.net.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 java.net.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 java.net.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 java.net.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, java.net.InetAddress bind, java.net.InetAddress mcastAddress, int ttl, int soTimeout, MembershipListener service, MessageListener msgservice, boolean localLoopbackDisabled)` Create a new mcast service impl

Method Summary

Methods
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, java.net.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 java.net.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 java.net.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 java.net.DatagramPacket sendPacket
```
  Reuse the sendPacket, no need to create a new one everytime
- receivePacket
```
protected java.net.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 java.net.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 java.util.concurrent.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 java.lang.Object expiredMutex
```

Constructor Detail

McastServiceImpl

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

Create a new mcast service impl

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; service - - the callback service; localLoopbackDisabled - - disable loopbackMode
Throws:: java.io.IOException

Method Detail

init

public void init()
          throws java.io.IOException

Throws:: java.io.IOException

setupSocket

protected void setupSocket()
                    throws java.io.IOException

Throws:: java.io.IOException

start
```
public void start(int level)
           throws java.io.IOException
```
Start the service

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

Throws:

java.io.IOException - if the service fails to start

java.lang.IllegalStateException - if the service is already started

stop
```
public boolean stop(int level)
             throws java.io.IOException
```
Stops the service

Throws:

java.io.IOException - if the service fails to disconnect from the sockets

receive
```
public void receive()
             throws java.io.IOException
```
Receive a datagram packet, locking wait

Throws:

java.io.IOException

checkExpired
```
protected void checkExpired()
```

send

public void send(boolean checkexpired)
          throws java.io.IOException

Send a ping

Throws:: java.io.IOException

send

public void send(boolean checkexpired,
        java.net.DatagramPacket packet)
          throws java.io.IOException

Throws:: java.io.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)

Class McastServiceImpl

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MAX_PACKET_SIZE

sm

doRunSender

doRunReceiver

startLevel

socket

member

address

port

timeToExpiration

sendFrequency

sendPacket

receivePacket

membership

service

msgservice

receiver

sender

mcastTTL

mcastSoTimeout

mcastBindAddress

recoveryCounter

recoverySleepTime

recoveryEnabled

executor

localLoopbackDisabled

expiredMutex

Constructor Detail

McastServiceImpl

Method Detail

init

setupSocket

start

stop

receive

checkExpired

send

send

getServiceStartTime

getRecoveryCounter

isRecoveryEnabled

getRecoverySleepTime

getChannel

setChannel

setRecoveryCounter

setRecoveryEnabled

setRecoverySleepTime