Free queued script

Quartz 1.6.5 brings you a useful scheduling system that can be integrated with, or used along side virtually any J2EE or J2SE application

Applications can vary from the largest e-commerce system to the smallest stand-alone application. Quartz can be used to create simple or complex schedules for executing tens, hundreds, or even tens-of- tousands of jobs; jobs whose tasks are defined as standard Java components or EJBs.

The Quartz Scheduler includes many enterprise-class features, such as JTA transactions and clustering.

Major Features

1. Job Scheduling:
   • At a certain time of day (to the millisecond)
   • On certain days of the week
   • On certain days of the month
   • On certain days of the year
   • Not on certain days listed within a registered Calendar (such as business holidays)
   • Repeated a specific number of times
   • Repeated until a specific time/date
   • Repeated indefinitely
   • Repeated with a delay interval
2. Job Execution:
   • Jobs can be any Java class that implements the simple Job interface, leaving infinite possibilities for the work the Jobs can perform.
   • Job class instances can be instantiated by Quartz, or by the applications framework.
   • When a Trigger occurs, the scheduler notifies zero or more Java objects implementing the JobListener and TriggerListener interfaces (listeners can be simple Java objects, or EJBs, or JMS publishers, etc.). These listeners are also notified after the Job has executed.
   • As Jobs are completed, they return a JobCompletionCode which informs the scheduler of success or failure. The JobCompletionCode can also instruct the scheduler of any actions it should take based on the success/fail code such as immediate re-execution of the Job.
3. Job Persistence:
   • The design of Quartz includes a JobStore interface that can be implemented to provide various mechanisms for the storage of jobs.
   • With the use of the included JDBCJobStore, all Jobs and Triggers configured as "non-volatile" are stored in a relational database via JDBC.
   • With the use of the included RAMJobStore, all Jobs and Triggers are stored in RAM and therefore do not persist between program executions but this has the advantage of not requiring an external database.
4. Transactions:
   • Quartz can participate in JTA transactions, via the use of JobStoreCMT (a subclas of JDBCJobStore).
   • Quartz can manage JTA transactions (begin and commit them) around the execution of a Job, so that the work the Job does happens within a JTA transaction.
5. Clustering:
   • Fail-over.
   • Load balancing.
6. Listeners & Plug-Ins:
   • Applications can catch scheduling events to monitor or control job/trigger behavior by implementing one or more listener interfaces.
   • The Plug-In mechanism can be used add functionality to Quartz, such keeping a history of job executions, or loading job and trigger definitions from a file.
   • Quartz ships with a number of "factory built" plug-ins and listeners.
7. Runtime Environments:
   • Quartz can run embedded within another free standing application
   • Quartz can be instantiated within an application server (or servlet container), and participate in XA transactions
   • Quartz can run as a stand-alone program (within its own Java Virtual Machine), to be used via RMI
   • Quartz can be instantiated as a cluster of stand-alone programs (with load-balance and fail-over capabilities)

Enhancements

• Records in QRTZ_TRIGGER_LISTENERS table are deleted when trigger is paused and resumed
• Logging Trigger History Plugin.trigger Misfired writes incorrect message
• Send Destination Message Job throws naming exception
• Send Queue Message Job throws Class Cast Exception when used with xml plugin acquire Next Trigger executing on Managed Tx Connection when using JobStoreCMT and configured not to acquire triggers within lock

C Threads 3.6 offers you a wonderful application which provides process scoping, a feature that has been greatly missed in the linux community. The aim of this library, is to provide the programmer with an easy to use class, that can be further inherited to provide a rich set of threaded functionality rarely seen in a linux environment.

Full C is provided, without any wrapping around underlying C code, which gives more compact and faster objects. The library provides process scoping, a feature that has been greatly missed in the linux community. This feature allows different programs to share memory and control variables, for synchronization and direct data communications.

It has the ability to simulate asynchronous I/O on file descriptors. An example provided with the library, shows how to communicate with a modem with an asynchronous method where data is obtained and stored in a priority queue, giving the main process full ability to handle other tasks. Such an I/O class, can be used to handle data input from several different file descriptors simultaneously, but is limited to handling only one server file descriptor per class.