com.caucho.admin
Class PingThread

java.lang.Object
  com.caucho.admin.PingThread

All Implemented Interfaces:

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

Direct Known Subclasses:

PingMailer, PingThread

@Configurable
@Unbound
@Singleton
public class PingThread
extends java.lang.Object
implements java.lang.Runnable, AlarmListener, EnvironmentListener

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.
void	environmentBind(EnvironmentClassLoader loader) Bind the ping.
void	environmentConfigure(EnvironmentClassLoader loader) Configure the ping.
void	environmentStart(EnvironmentClassLoader loader) Start the pinger.
void	environmentStop(EnvironmentClassLoader loader) Stop the pinger.
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	setFreezeTimeout(Period freezeTimeout) Sets the response time to detect a frozen jvm
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	stop() Stop the pinger.
java.lang.String	toString()

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

@Configurable
public void setPingHost(java.lang.String pingHost)

Sets the server's ping host

getPingPort

public int getPingPort()

Returns the server's ping port

setPingPort

@Configurable
public void setPingPort(int pingPort)

Sets the server's ping port

addUrl

@Configurable
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

@Configurable
public void setSleepTime(Period sleepTime)

Sets the sleep time between pings

setFreezeTimeout

@Configurable
public void setFreezeTimeout(Period freezeTimeout)

Sets the response time to detect a frozen jvm

setInitialSleepTime

@Configurable
public void setInitialSleepTime(Period sleepTime)

Sets the sleep time on startup

getRetryTime

public long getRetryTime()

Gets the retry time between failing pings

setRetryTime

@Configurable
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

@Configurable
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

@Configurable
public void setSocketTimeout(Period timeout)

Sets the number of times to retry before giving up

init

@PostConstruct
public void init()

Initialize the pinger.

environmentStart

public void environmentStart(EnvironmentClassLoader loader)

Start the pinger.

Specified by:

environmentStart in interface EnvironmentListener

environmentStop

public void environmentStop(EnvironmentClassLoader loader)

Stop the pinger.

Specified by:

environmentStop in interface EnvironmentListener

environmentConfigure

public void environmentConfigure(EnvironmentClassLoader loader)

Configure the ping.

Specified by:

environmentConfigure in interface EnvironmentListener

environmentBind

public void environmentBind(EnvironmentClassLoader loader)

Bind the ping.

Specified by:

environmentBind in interface EnvironmentListener

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.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object