Interface IJobsScheduler

  • All Superinterfaces:
    ISubsystem

    public interface IJobsScheduler
    extends ISubsystem
    An interface that represents the job scheduler component. A JobScheduler is a daemon thread that handles scheduled jobs like cron would do with different jobs. This daemon wakes up at a pre-configured interval to see if there is any job to be done, if so, a thread is created to execute the job(s).

    The interval jobsScheduler.interval in the configuration is specified as number of minutes. If not set, the default is 1 minute. Note that the cron specification for each job CAN NOT be finer than the granularity of the Scheduler daemon interval. For example, if the daemon interval is set to 5 minute, a job cron for every minute at 7am on each Tuesday (e.g. * 7 * * 2) will result in the execution of the job thread only once every 5 minutes during that hour. The inteval value is recommended at 1 minute, setting it otherwise has the potential of forever missing the beat. Use with caution.

    Version:
    $Revision$, $Date$
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String ID
      The ID of this component
      static java.lang.String PROP_CLASS
      constant that represents the configuration parameter "class" for this component in CMS.cfg.
      static java.lang.String PROP_ENABLED
      constant that represents the configuration parameter "enabled" for this component in CMS.cfg.
      static java.lang.String PROP_IMPL
      constant that represents the configuration parameter "impl" for this component in CMS.cfg.
      static java.lang.String PROP_INTERVAL
      constant that represents the configuration parameter "interval" for this component in CMS.cfg.
      static java.lang.String PROP_JOB
      constant that represents the configuration parameter "job" for this component in CMS.cfg.
      static java.lang.String PROP_PLUGIN
      constant that represents the configuration parameter "pluginName" for this component in CMS.cfg.
    • Field Detail

      • PROP_ENABLED

        static final java.lang.String PROP_ENABLED
        constant that represents the configuration parameter "enabled" for this component in CMS.cfg. The value of which tells CMS whether the JobsScheduler is enabled or not
        See Also:
        Constant Field Values
      • PROP_INTERVAL

        static final java.lang.String PROP_INTERVAL
        constant that represents the configuration parameter "interval" for this component in CMS.cfg. The value of which tells CMS the interval that the JobsScheduler thread should wake up and look for jobs to execute
        See Also:
        Constant Field Values
      • PROP_CLASS

        static final java.lang.String PROP_CLASS
        constant that represents the configuration parameter "class" for this component in CMS.cfg. The values of which are the actual implementation classes
        See Also:
        Constant Field Values
      • PROP_JOB

        static final java.lang.String PROP_JOB
        constant that represents the configuration parameter "job" for this component in CMS.cfg. The values of which gives configuration information specific to one single job instance. There may be multiple jobs served by the jobsScheduler
        See Also:
        Constant Field Values
      • PROP_IMPL

        static final java.lang.String PROP_IMPL
        constant that represents the configuration parameter "impl" for this component in CMS.cfg. The values of which are actual plugin implementation(s)
        See Also:
        Constant Field Values
      • PROP_PLUGIN

        static final java.lang.String PROP_PLUGIN
        constant that represents the configuration parameter "pluginName" for this component in CMS.cfg. The value of which gives the pluginName for the job it associates with
        See Also:
        Constant Field Values
    • Method Detail

      • getPlugins

        java.util.Hashtable<java.lang.String,​JobPlugin> getPlugins()
        Retrieves all the job implementations.
        Returns:
        a Hashtable of available job plugin implementations
      • getInstances

        java.util.Hashtable<java.lang.String,​IJob> getInstances()
        Retrieves all the job instances.
        Returns:
        a Hashtable of job instances
      • getConfigParams

        java.lang.String[] getConfigParams​(java.lang.String implName)
                                    throws EJobsException
        Retrieves the configuration parameters of the given implementation. It is used to return to the Console for configuration
        Parameters:
        implName - the pulubin implementation name
        Returns:
        a String array of required configuration parameters of the given implementation.
        Throws:
        EJobsException - when job plugin implementation can not be found, instantiation is impossible, permission problem with the class.
      • log

        void log​(int level,
                 java.lang.String msg)
        Writes a message to the system log.
        Parameters:
        level - an integer representing the log message level. Depending on the configuration set by the administrator, this value is a determining factor for whether this message will be actually logged or not. The lower the level, the higher the priority, and the higher chance it will be logged.
        msg - the message to be written. Ideally should call CMS.getLogMessage() to get the localizable message from the log properties file.
      • setInterval

        void setInterval​(int minutes)
        Sets daemon's wakeup interval.
        Parameters:
        minutes - time in minutes that is to be the frequency of JobsScheduler wakeup call.
      • startDaemon

        void startDaemon()
        Starts up the JobsScheduler daemon. Usually called from the initialization method when it's successfully initialized.
      • createJobCron

        IJobCron createJobCron​(java.lang.String cs)
                        throws EBaseException
        Creates a job cron. Each job is associated with a "cron" which specifies the rule of frequency that this job should be executed (e.g. every Sunday at midnight). This method is called by each job at initialization time.
        Parameters:
        cs - the string that represents the cron. See IJobCron for detail of the format.
        Returns:
        IJobCron an IJobCron
        Throws:
        EBaseException - when the cron string, cs, can not be parsed correctly