New in Quartz.Net 2.0-No More IStatefulJob

Welcome to the the third post of my New in Quartz.Net 2.0 series.

Goodbye IStatefulJob

Yes, it’s true. In Quartz.Net 2.0 the IStatefulJob has been marked as obsolete. To be sure, it’s still available to use, but if you are using IStatefulJobs you should think about migrating them to use the new Quartz.Net 2.0 features.

The Disallow Concurrent Execution Attribute

So how do I implement an IStatefulJob in Quartz.Net 2.0? Fortunately, it’s not very hard to do. You just need to mark your IJob with the new DisallowConcurrentExecutionAttribute. Any jobs that have this attribute set are only allowed to run one instance of the job at a time. Keep in mind that an instance is defined by a JobKey (job name and group combination), which means that if you have the same job type scheduled with a different job name or a different job group, you may get more than one instance of that type of job running at the same time.

The Persist Job Data After Execution Attribute

Seems simple enough so far? Well, it is! There is only one other thing to consider. If you want the scheduler to persist the job’s state between executions, you must also add the PersistJobDataAfterExecutionAttribute to the class. This attribute tells the scheduler that you would like for it store the job’s JobDataMap once it is finished executing.

One Last Thing

While you can use each of these attributes separately, if you are going to use the PersistJobDataAfterExecutionAttribute to persist your job’s state, you should always use the DisallowConcurrentExecutionAttribute, because if you don’t, you might find that your job state is corrupted due to race conditions.

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New in Quartz.Net 2.0–Directory Scan Job

This is the second post of the New in Quartz.Net 2.0 series. Today we will look at the DirectoryScanJob, which is a new job in Quartz.Net 2.0.
The DirectoryScanJob is very similar to the FileScanJob, which is available in Quartz.Net 1.0. As you can probably tell from the names, the main difference between the two jobs is that the DirectoryScanJob scans for changes in… you quessed it… a directory , whereas the FileScanJob scans for changes in… yes, you guessed it again… a file. If you’re not familiar with the FileScanJob, don’t worry, we will look at the DirectoryScanJob in detail.

Introducing the DirectoryScanJob

First, let’s take a look at what the documentation says about this new job:
“Inspects a directory and compares whether any files' "last modified dates" have changed since the last time it was inspected.  If one or more files have been updated (or created), the job invokes a "call-back" method on an identified DirectoryScanListener that can be found in the SchedulerContext.”
That seems pretty self explanatory, no? Basically, you tell the job that it needs to check a certain directory to see if new files have been added or if existing files have been modified. When the job is executed it checks the files and stores the file information in its JobDataMap. The next time the job runs, it compares the information stored in the job’s JobDataMap, with the files in the directory. If any changes are found, the job calls the FilesUpdatedOrAdded method of the IDirectoryScanListener that was configured for that job, passing in an arrary of FileInfo objects.

Configuring the DirectoryScanJob

To configure and use a DirectoryScanJob, you will need to set the following keys in the JobDataMap:
  1. DIRECTORY_NAME: this is the path to the directory that you want to monitor.
  2. DIRECTORY_SCAN_LISTENER_NAME: this is the name of the DirectoryScanListener that should called if changes are detected
  3. MINIMUM_UPDATE_AGE: this is an optional parameter which lets you specify how many milliseconds must have passed since the file’s last modified time in order to consider the file modified. If this parameter is not specified, it defaults to 5000 milliseconds.

Possible Uses for the DirectoryScanJob

There are many uses for the DirectoryScanJob, so let’s list a few here:
  • You could replace any FileWatcher type services that you might have implemented
  • Scan files uploaded by users for viruses
  • Schedule other jobs to process files that have been copied to the directory for processing
The next post in the series will cover a change to the IStatefulJob interface: it has been marked as obsolete and is replaced by a class attribute!

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New in Quartz.Net 2.0–The Calendar Interval Trigger

This is the first post of what will become a series of posts highlighting the new features that will be available in Quartz.Net 2.0.
To kick off the series, we will take a look at the CalendarIntervalTrigger. This trigger is used to fire jobs based on a recurring calendar time interval. The following time intervals are available:

IntervalUnit
Minute
Hour
Day
Week
Month
Year
This trigger has a RepeatInterval property, which can be used to indicate that the trigger should fire every N intervals. For example, if you set the RepeatIntervalUnit to Week and the RepeatInterval to 2, your trigger will fire every two weeks.
Here is what the source code documentation says about this trigger:
A concrete ITrigger that is used to fire a IJobDetail based upon repeating calendar time intervals.
The trigger will fire every N (see RepeatInterval) units of calendar time (see RepeatIntervalUnit) as specified in the trigger's definition.  This trigger can achieve schedules that are not possible with ISimpleTrigger (e.g because months are not a fixed number of seconds) or ICronTrigger (e.g. because "every 5 months" is not an even divisor of 12).
If you use an interval unit of IntervalUnit.Month then care should be taken when setting the startTime value that is on a day near the end of the month.  For example, if you choose a start time that occurs on January 31st, and have a trigger with unit IntervalUnit.Month and interval 1, then the next fire time will be February 28th, and the next time after that will be March 28th - and essentially each subsequent firing will occur on the 28th of the month, even if a 31st day exists.  If you want a trigger that always fires on the last day of the month - regardless of the number of days in the month, you should use ICronTrigger.
That’s it for today’s “New in Quartz.Net 2.0” post. Stay tuned for more, coming soon!

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Installing Quartz.Net 2.0 as a Windows Service

UPDATE: I've written a new post that has been updated with the release of Beta 1. Take a look at this newer post instead.
Quartz.Net 2.0 is currently under development. No official release (beta or otherwise) is available yet but if you really want to get started with it, you can download the source code from Github and build it yourself. In this post I am going to describe how to install the latest version of Quartz.Net 2.0 from source.

Getting the Source

If you are familiar with Git, Github and how it works, then just download the repository locally using whatever method you prefer. There are a lot of posts and even a free book on how to use Git, so I am not going to go over that stuff here.
If you’re not familiar with how to use Git or Github, then go ahead and download a zipped file of the source from here.
At this point I am going to assume that you have already downloaded the Quartz.Net source code and that it is in a folder somewhere on your drive. On my box I have downloaded the source to C:\git\quartznet, and the image below shows what that folder looks like. Your folder should look similar to the screenshot below.
image

Building The Source Code

Since this post is about installing Quartz.Net 2.0 as a windows service, let’s build the server project.
Instructions for Visual Studio 2008 and .Net 3.5
Double click on the Quartz.Server.2008.sln file if you have Visual Studio 2008 installed. This will open the file in VS 2008. Build the solution by pressing F6. This will build the binaries targeting the 3.5 framework. The build output for this project can be found under the build\3.5\Debug\Quartz.Server folder, as shown below.
image
Instructions for Visual Studio 2010 and .Net 4.0
If you have Visual Studio 2010 installed, double click on the Quartz.Server.2010.sln file to open it in VS 2010. Build the solution by pressing F6. This will build the binaries targeting the 4.0 framework. The build output for this project can be found under the build\4.0\Debug\Quartz.Server folder, as shown below.
image

Installing Quartz.Net 2.0 as a Windows Service

Now that you have built the source code, let’s install the service. Open a command prompt as administrator (if you are running a Vista or later OS) and cd to the directory that contains the Quartz.Server.exe file. This directory will be different based on whether you use VS 2008 or VS 2010, so double check that the file exists first in one of the paths that I mention above. At this point, all that is left is to install the service. Type the following into your command prompt:
Quartz.Server.exe install
If all goes well, then you should see the following in your command prompt window (replace 3.5 with 4.0 where appropriate):
image
By default, the service is installed with a startup type of automatic and under the Local System account. To uninstall, type the following into your command prompt:
Quartz.Server.exe uninstall
Now, go fire that puppy up and start experimenting!
As always, let me know in the comments if this stuff is useful and what topics you’re interested in reading about.

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