Package org.apache.catalina.tribes.group.interceptors

Class TcpPingInterceptor

java.lang.Object

org.apache.catalina.tribes.group.ChannelInterceptorBase

org.apache.catalina.tribes.group.interceptors.TcpPingInterceptor

All Implemented Interfaces:

ChannelInterceptor, TcpPingInterceptorMBean, Heartbeat, MembershipListener

public class TcpPingInterceptor
extends ChannelInterceptorBase
implements TcpPingInterceptorMBean

Sends periodic TCP pings to cluster members for health monitoring.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	TcpPingInterceptor.PingThread	Background thread that sends periodic pings.

Nested classes/interfaces inherited from interface org.apache.catalina.tribes.ChannelInterceptor

ChannelInterceptor.InterceptorEvent

Field Summary

Fields

Modifier and Type	Field	Description
protected static java.util.concurrent.atomic.AtomicInteger	cnt	Counter for naming ping threads.
protected long	interval	Ping interval in milliseconds.
protected boolean	running	Whether the ping thread is currently running.
protected static StringManager	sm	The string manager for this package.
protected boolean	staticOnly	Whether to ping only static members.
protected static byte[]	TCP_PING_DATA	Test payload sent during ping checks.
protected TcpPingInterceptor.PingThread	thread	The background ping thread.
protected boolean	useThread	Whether to use a dedicated thread for pinging.

Fields inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase

optionFlag

Constructor Summary

Constructors

Constructor	Description
TcpPingInterceptor()	Constructs a new TcpPingInterceptor.

Method Summary

Modifier and Type	Method	Description
long	getInterval()	Returns the ping interval in milliseconds.
boolean	getStaticOnly()	Returns whether static-only mode is enabled.
boolean	getUseThread()	Returns whether a dedicated ping thread is used.
void	heartbeat()	The heartbeat() method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.
void	messageReceived(ChannelMessage msg)	The messageReceived is invoked when a message is received.
protected void	sendPing()	Sends a ping to cluster members.
protected void	sendPingMessage(Member[] members)	Sends a ping message to the specified members.
void	setInterval(long interval)	Sets the ping interval in milliseconds.
void	setStaticOnly(boolean staticOnly)	Sets whether to ping only static members.
void	setUseThread(boolean useThread)	Sets whether to use a dedicated thread for pinging.
void	start(int svc)	Starts up the channel.
void	stop(int svc)	Shuts down the channel.

Methods inherited from class org.apache.catalina.tribes.group.ChannelInterceptorBase

fireInterceptorEvent, getChannel, getLocalMember, getMember, getMembers, getNext, getOptionFlag, getPrevious, hasMembers, memberAdded, memberDisappeared, okToProcess, sendMessage, setChannel, setNext, setOptionFlag, setPrevious

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.catalina.tribes.group.interceptors.TcpPingInterceptorMBean

getOptionFlag

Field Detail

sm

protected static final StringManager sm

The string manager for this package.

TCP_PING_DATA

protected static final byte[] TCP_PING_DATA

Test payload sent during ping checks.

interval

protected long interval

Ping interval in milliseconds.

useThread

protected boolean useThread

Whether to use a dedicated thread for pinging.

staticOnly

protected boolean staticOnly

Whether to ping only static members.

running

protected volatile boolean running

Whether the ping thread is currently running.

thread

protected TcpPingInterceptor.PingThread thread

The background ping thread.

cnt

protected static final java.util.concurrent.atomic.AtomicInteger cnt

Counter for naming ping threads.

Constructor Detail

TcpPingInterceptor

public TcpPingInterceptor()

Constructs a new TcpPingInterceptor.

Method Detail

start

public void start(int svc)
           throws ChannelException

Description copied from interface: ChannelInterceptor

Starts up the channel. This can be called multiple times for individual services to start The svc parameter can be the logical or value of any constants

Specified by:

start in interface ChannelInterceptor

Overrides:

start in class ChannelInterceptorBase

Parameters:

svc - one of:

• Channel.DEFAULT - will start all services
• Channel.MBR_RX_SEQ - starts the membership receiver
• Channel.MBR_TX_SEQ - starts the membership broadcaster
• Channel.SND_TX_SEQ - starts the replication transmitter
• Channel.SND_RX_SEQ - starts the replication receiver

Throws:

ChannelException - if a startup error occurs or the service is already started.

See Also:

Channel

stop

public void stop(int svc)
          throws ChannelException

Description copied from interface: ChannelInterceptor

Shuts down the channel. This can be called multiple times for individual services to shut down. The svc parameter can be the logical or value of any constants

Specified by:

stop in interface ChannelInterceptor

Overrides:

stop in class ChannelInterceptorBase

Parameters:

svc - one of:

• Channel.DEFAULT - will shut down all services
• Channel.MBR_RX_SEQ - stops the membership receiver
• Channel.MBR_TX_SEQ - stops the membership broadcaster
• Channel.SND_TX_SEQ - stops the replication transmitter
• Channel.SND_RX_SEQ - stops the replication receiver

Throws:

ChannelException - if a startup error occurs or the service is already started.

See Also:

Channel

heartbeat

public void heartbeat()

Description copied from interface: ChannelInterceptor

The heartbeat() method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.

Specified by:

heartbeat in interface ChannelInterceptor

Specified by:

heartbeat in interface Heartbeat

Overrides:

heartbeat in class ChannelInterceptorBase

getInterval

public long getInterval()

Description copied from interface: TcpPingInterceptorMBean

Returns the ping interval in milliseconds.

Specified by:

getInterval in interface TcpPingInterceptorMBean

Returns:

the ping interval

setInterval

public void setInterval(long interval)

Sets the ping interval in milliseconds.

Parameters:

interval - the interval in milliseconds

setUseThread

public void setUseThread(boolean useThread)

Sets whether to use a dedicated thread for pinging.

Parameters:

useThread - true to use a dedicated thread

setStaticOnly

public void setStaticOnly(boolean staticOnly)

Sets whether to ping only static members.

Parameters:

staticOnly - true to ping only static members

getUseThread

public boolean getUseThread()

Description copied from interface: TcpPingInterceptorMBean

Returns whether a dedicated ping thread is used.

Specified by:

getUseThread in interface TcpPingInterceptorMBean

Returns:

true if a dedicated thread is used

getStaticOnly

public boolean getStaticOnly()

Returns whether static-only mode is enabled.

Returns:

true if only static members are pinged

sendPing

protected void sendPing()

Sends a ping to cluster members.

sendPingMessage

protected void sendPingMessage(Member[] members)

Sends a ping message to the specified members.

Parameters:

members - the members to ping

messageReceived

public void messageReceived(ChannelMessage msg)

Description copied from interface: ChannelInterceptor

The messageReceived is invoked when a message is received. ChannelMessage.getAddress() is the sender, or the reply-to address if it has been overwritten.

Specified by:

messageReceived in interface ChannelInterceptor

Overrides:

messageReceived in class ChannelInterceptorBase

Parameters:

msg - ChannelMessage