com.caucho.server.admin
Class PingThread

java.lang.Object
  com.caucho.jca.AbstractResourceAdapter
      com.caucho.server.admin.PingThread

All Implemented Interfaces:

AlarmListener, java.lang.Runnable, java.util.EventListener, ResourceAdapter

Direct Known Subclasses:

PingMailer

public class PingThread
extends AbstractResourceAdapter
implements java.lang.Runnable, AlarmListener

A thread to restart the Resin server if it fails for some reason.

This pinging only catches some problems because it's running in the same JDK process as Resin itself. If the entire JDK freezes, this thread will freeze as well. Assuming the JDK doesn't freeze, the PingThread will catch errors like deadlocks.

Constructor Summary

PingThread()

Method Summary

void	addURL(java.lang.String url) Adds a new URL to be tested.
protected boolean	checkPing(Path url, int count) Called to check if the connection is alive.
java.lang.String	getPingHost() Returns the server's ping host
int	getPingPort() Returns the server's ping port
long	getRetryTime() Gets the retry time between failing pings
long	getSleepTime() Gets the sleep time between pings
long	getSocketTimeout() Gets the time to wait on a non-responsive socket before giving up.
int	getTryCount() Gets the number of times to retry before giving up
void	handleAlarm(Alarm alarm) Periodically pings the server to check for anything going wrong.
void	init() Initialize the pinger.
protected void	pingFailed(Path url) Called if the ping completely fails.
protected void	pingFailedOnce(Path url, int count, ReadStream is) Called if the ping fails once.
void	run() The ping thread checks to make sure the alarm has been successful.
void	setInitialSleepTime(Period sleepTime) Sets the sleep time on startup
void	setPingHost(java.lang.String pingHost) Sets the server's ping host
void	setPingPort(int pingPort) Sets the server's ping port
void	setRetryTime(Period retryTime) Sets the retry time between failing pings
void	setSleepTime(Period sleepTime) Sets the sleep time between pings
void	setSocketTimeout(Period timeout) Sets the number of times to retry before giving up
void	setTryCount(int tryCount) Sets the number of times to retry before giving up
void	start(BootstrapContext cxt) Start the pinger.
void	stop() Stop the pinger.
java.lang.String	toString()

Methods inherited from class com.caucho.jca.AbstractResourceAdapter

endpointActivation, endpointDeactivation, getXAResources

Methods inherited from class java.lang.Object

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

Constructor Detail

PingThread

public PingThread()

Method Detail

getPingHost

public java.lang.String getPingHost()

Returns the server's ping host

setPingHost

public void setPingHost(java.lang.String pingHost)

Sets the server's ping host

getPingPort

public int getPingPort()

Returns the server's ping port

setPingPort

public void setPingPort(int pingPort)

Sets the server's ping port

addURL

public void addURL(java.lang.String url)

Adds a new URL to be tested.

getSleepTime

public long getSleepTime()

Gets the sleep time between pings

setSleepTime

public void setSleepTime(Period sleepTime)

Sets the sleep time between pings

setInitialSleepTime

public void setInitialSleepTime(Period sleepTime)

Sets the sleep time on startup

getRetryTime

public long getRetryTime()

Gets the retry time between failing pings

setRetryTime

public void setRetryTime(Period retryTime)

Sets the retry time between failing pings

getTryCount

public int getTryCount()

Gets the number of times to retry before giving up

setTryCount

public void setTryCount(int tryCount)

Sets the number of times to retry before giving up

getSocketTimeout

public long getSocketTimeout()

Gets the time to wait on a non-responsive socket before giving up.

setSocketTimeout

public void setSocketTimeout(Period timeout)

Sets the number of times to retry before giving up

init

public void init()

Initialize the pinger.

start

public void start(BootstrapContext cxt)

Start the pinger.

Specified by:

start in interface ResourceAdapter

Overrides:

start in class AbstractResourceAdapter

handleAlarm

public void handleAlarm(Alarm alarm)

Periodically pings the server to check for anything going wrong.

Specified by:

handleAlarm in interface AlarmListener

run

public void run()

The ping thread checks to make sure the alarm has been successful. PingThread uses this separate thread to minimize the possible freezes. run() can only freeze if the entire JVM is frozen and in that case, there's nothing a Java-based ping can do about the situation.

Specified by:

run in interface java.lang.Runnable

checkPing

protected boolean checkPing(Path url,
                            int count)
                     throws java.lang.Exception

Called to check if the connection is alive. An custom class might override checkPing if it wanted to handle a different status.

Parameters:

url - the url to test

count - the number of times the url has been checked without success.

Returns:

true if the ping succeeds

Throws:

java.lang.Exception

pingFailedOnce

protected void pingFailedOnce(Path url,
                              int count,
                              ReadStream is)
                       throws java.lang.Exception

Called if the ping fails once.

Throws:

java.lang.Exception

pingFailed

protected void pingFailed(Path url)
                   throws java.lang.Exception

Called if the ping completely fails.

Throws:

java.lang.Exception

stop

public void stop()

Stop the pinger.

Specified by:

stop in interface ResourceAdapter

Overrides:

stop in class AbstractResourceAdapter

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object