de.schwarzrot.startup
Class ServiceManager

java.lang.Object
  de.schwarzrot.app.support.AbstractService<ServiceConfig>
      de.schwarzrot.startup.ServiceManager

All Implemented Interfaces:

MainEntry<ServiceConfig>, Service<ServiceConfig>, UserNameProvider, Runnable

public class ServiceManager
extends AbstractService<ServiceConfig>

a manager class used to start and stop other services remotely. Services that should be managed must have a valid database entry, so this manager class works together with a database.

The ServiceDefinition includes 2 script filenames and a trigger filename. The preStart-script will be executed before starting the service. That script can be used to vomit a wakeonlan package or something like that. The waitPreStart-time is the time, the ServiceManager waits after executing the pre-start-script, before really starting the service. That time can be set to reflect the boot-time of the dynamically started machine.

The triggerfile can be used to give a feedback from the pre-start-script to the ServiceManager. If a triggerfile is defined, the service will only be startet, if that file exists. Both, the pre-start-script and the post-end-script get the absolute path of the triggerfile as second parameter, so there's no need to hardcode it in the scripts.

The first parameter of the scripts will be "start" or "stop", depending on whether the script is defined as pre-start-script or as post-end-script. This way it is possible to use the same script for both actions.

The post-end-script is the counterpart of the pre-start-script and may be used to trigger a shutdown of the dynamically started machine. The waitPostEnd-time is the time, the ServiceManager waits after stopping the service, before it executes the post-end-script. The script gets the absolute path of the triggerfile, so it can remove it for cleanup.

Lifecycle of a service:
Initial status of a service is STOPPED and pid is 0. At user-request status is set to START_REQUESTED.

• check whether the ServiceDefinition contains a valid scriptPreStart. If so, set the status to STARTING, set dtStarted to current time and execute the scriptPreStart. If scriptPreStart is empty or invalid, set status to STARTED and start the service.
• If status is STARTING, check whether dtStarted plus waitPreStart is gone. If so, check whether a triggerfile is defined. If so, check the existance of that file. If the file does not exists, means the pre-start-script has failed. Set status to STOP_REQUESTED. If the triggerfile exists, set the status to STARTED and start the service
• If status is STARTED or RUNNING, determine the pid for the service. If pid is not 0, check whether the pid equals the stored pid. If not, update the stored pid.
  If the pid of the service is 0, set the dtStopped to current time and status to STOPPING.
• If the status is STOPPING, check whether dtStopped plus waitPostEnd is gone. If so, set the status to STOPPED and check whether a scriptPostEnd is defined and valid. If so, execute it.

The starter setup ensures the cyclic performing of the workloop, as well as the relaxed sleeping in between.

The ServiceManager will be started by a shellscript wrapper usually in root-mode, so it is able to start the other services with the userid defined at the services database entry.

Author:

Reinhard Mantey

Field Summary

protected static String

PIDFILE_PROPERTY

Constructor Summary

ServiceManager()

Method Summary

protected void	checkRunningService(ServiceDefinition sd)
protected void	doAutoStart(ServiceDefinition sd)
protected void	doServiceStarted(ServiceDefinition sd)
protected void	doServiceStarting(ServiceDefinition sd)
protected void	doServiceStopping(ServiceDefinition sd)
protected void	doStartRequested(ServiceDefinition sd)
protected void	doStopRequested(ServiceDefinition sd)
protected void	executeScript(ServiceDefinition sd, boolean startScript)
String	getApplicationName() print the application name - may be localized.
protected Integer	getMyProcessID()
boolean	isIdle() will be used by the ServiceLauncher to determine, whether it should sleep between the calls to Service.run().
static void	main(String[] args)
protected void	readMyProcessID()
void	run()
void	setupLate() second stage of initialization.
protected void	startService(ServiceDefinition sd)
protected void	stopService(ServiceDefinition sd, boolean beSmart)
void	usage() tell the user about the right usage
protected int	validatePid(ServiceDefinition sd)

Methods inherited from class de.schwarzrot.app.support.AbstractService

getAppArgs, getAppInfo, getAppInfo, getApplicationDefaults, getConfig, getLogger, getUserName, isShutdownRequested, setAppArgs, setConfig, setShutdownRequested, setupEarly

Methods inherited from class java.lang.Object

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

Field Detail

PIDFILE_PROPERTY

protected static final String PIDFILE_PROPERTY

See Also:

Constant Field Values

Constructor Detail

ServiceManager

public ServiceManager()

Method Detail

getApplicationName

public String getApplicationName()

Description copied from interface: MainEntry

print the application name - may be localized. For identifying purpose consider using SystemDefault.applicationID

Specified by:

getApplicationName in interface MainEntry<ServiceConfig>

Overrides:

getApplicationName in class AbstractService<ServiceConfig>

Returns:

- the applications name

isIdle

public boolean isIdle()

Description copied from interface: Service

will be used by the ServiceLauncher to determine, whether it should sleep between the calls to Service.run().

Returns:

true if the Service was idle, otherwise false

run

public void run()

setupLate

public void setupLate()

Description copied from interface: Service

second stage of initialization. Will be called after loading all referenced external jars, right before starting the service loop.

usage

public void usage()

Description copied from interface: MainEntry

tell the user about the right usage

checkRunningService

protected void checkRunningService(ServiceDefinition sd)

doAutoStart

protected void doAutoStart(ServiceDefinition sd)

doServiceStarted

protected void doServiceStarted(ServiceDefinition sd)

doServiceStarting

protected void doServiceStarting(ServiceDefinition sd)

doServiceStopping

protected void doServiceStopping(ServiceDefinition sd)

doStartRequested

protected void doStartRequested(ServiceDefinition sd)

doStopRequested

protected void doStopRequested(ServiceDefinition sd)

executeScript

protected void executeScript(ServiceDefinition sd,
                             boolean startScript)

getMyProcessID

protected Integer getMyProcessID()

readMyProcessID

protected void readMyProcessID()

startService

protected void startService(ServiceDefinition sd)

stopService

protected void stopService(ServiceDefinition sd,
                           boolean beSmart)

validatePid

protected int validatePid(ServiceDefinition sd)

main

public static void main(String[] args)