Configuring Quartz.Net with an ADO.Net Job Store (AdoJobStore) – Part 1

  • J
  • Date : April 28, 2010
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Quartz.Net stores all of its job related configuration in an aptly named JobStore. There are two different kinds of job stores available out of the box: RAMJobStore and AdoJobStore. By default, Quartz.Net uses a RAMJobstore. The RAMJobStore is extremely simple to configure, but it is a volatile store, so all job configuration is lost whenever the scheduler is restarted.
If you need your job configuration to be persisted between scheduler restarts and/or you are going to be running more than one instance of the scheduler in a cluster, you will need to use the AdoJobStore. This job store uses ADO.Net to persist all the job configuration information in a database. The following table shows the most common database providers that are supported, as well the name of the Quartz.Net database provider to use. The full list of providers can be found in lesson 9 of the Quartz.Net tutorial.

Database Provider Quartz.Net Provider Name
SQL Server driver for .NET Framework 2.0 SqlServer-20
Oracle Driver (by Microsoft) OracleClient-20
MySQL Connector/:NET v. 5.1 (.NET 2.0) MySql-51
SQLite ADO.NET 2.0 Provider v. 1.0.56 (.NET 2.0) SQLite-10
This post will focus on configuring the job store for SQL Server. If you’d like to see similar posts for the other databases, please let me know in the comments.
First, let’s take a look at the steps you will need to follow to start using an ADO.Net job store:
  1. Set up the database by creating the tables that Quartz.Net will use.
  2. Configure the scheduler to use the database server that you just set up.
It’s not that complicated, is it?

Step 1: Setting up the database

First, you will need to locate the setup script for your database server. In our case, we will use the SQL Server setup script. All setup scripts are located under the database/tables folder of the Quartz.Net distribution. The script we are looking for is called tables_sqlServer.sql. Open the script in a text editor and update the USE [enter_db_name_here] statement to point to whatever database you want to use. Once you’ve changed the database name in the script, you can go ahead and execute it. This script will create several tables in the database you set in the script. All of the Quartz.Net tables will be prefixed by QRTZ_ . Once you’ve successfully created all the tables, it’s time to configure the scheduler.
In Part 2 we will cover configuration of the scheduler.

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Creating a Custom Job in Quartz.Net

If you use Quartz.Net and you want to do anything other than run  a batch file, then chances are you’ll want to create a custom job. Fortunately, creating it is not hard at all. Let’s get started.
Here’s a quick rundown of what you need to do. First, you’ll need to add a reference to Quartz.dll in your project, Second, create a class that implements IJob. Third, put the code you want to run inside the Execute method. That’s it! That’s all you really need to create a custom job.
However, in order to get this job to execute, there are a couple more steps to follow and a few more things to be aware of, including some not-so-evident gotchas.
I’m going to assume that at this point, you have created your MyJob class and that it implements the IJob interface. Let’s talk  about what you need to do in addition to implementing the logic that you want your job to execute.

Handle Exceptions
You should wrap the code in the Execute method and handle any exceptions that you can. For exceptions that you cannot handle but that can be solved by running the job again, you should wrap your exception inside a JobExecutionException.
If you want the scheduler to try running the job again, then set the RefireImmediately property to true. Otherwise, set it to false. You also have other options, such as un-scheduling triggers, so take a look at the documentation for JobExecutionException.
If your job doesn’t know how to handle the exception that was thrown, then don’t catch it and let the scheduler handle it.
Deploy Your Custom Job
Deploying the custom job is as simple as copying the dll to the same folder where the Quartz.dll is. You can also deploy your dll in any manner that allows the runtime to locate the dll per the normal rules for dll resolution.
Beware of ConfigurationManager
Finally, I’d like to give you a heads up about using the ConfigurationManager to provide your job with configuration information. Don’t do it! It is best to include all the information that your job needs to execute in the job’s JobDataMap. The reason for this is simple. If you use ConfigurationManager and you are running Quartz.Net as a windows service, then the ConfigurationManager will try to look for configuration information in the Quartz.Net config file. If you are running Quartz.Net embedded inside your application, then this might not be an issue for you, but then again… it might.
Let’s wrap up this post by summarizing the steps needed to create a custom Quartz.Net job.
  1. Add a reference to Quartz.dll in your project.
  2. Create a class that implements IJob
  3. Implement the Execute method of the IJob interface.
  4. Catch exceptions and throw a JobExecutionException as needed.
  5. Copy the CustomJob dll to the same folder as Quartz.dll or somewhere that the runtime can locate it.
If you need more information, please let me know in the comments or read over documentation for IJob and for JobExcecutionException.

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Configuring Quartz.Net to use Log4net

If you’re considering using Quartz.Net, chances are you are using log4net as the logging framework for your application. We’ll assume that you already know how to configure log4net and that you just want to plug that configuration into Quartz.Net. So, how do we configure Quartz.Net to use log4net?
It’s not terribly complicated, since Quartz.Net is using Common.Logging. In this post we’ll consider 2 use cases for configuring Quartz.Net to use log4net: a standalone Quartz.Net server, and Quartz.Net embedded within your application. Fortunately for us, the process we need to follow to configure Quartz.Net is the same for both!

Configuring Quartz.Net with Log4net
To configure log4net for a standalone Quartz.Net server running as a windows service, we have to make some changes to the Quartz.Server.Service.exe.config file. This file should be in the directory where you have your Quartz.Net installation. If Quartz.Net is embedded in your application, then you will be modifying your application’s config file (web.config or yourapp.exe.config for example).
You will need to add 2 elements to the <configSections> element:
<section
name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
This bit lets you configure log4net directly from the quart configuration file. Now, add these elements:
<sectionGroup name="common">
      <section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
</sectionGroup>
This lets you configure the Commons Logging from the quartz configuration file as well. All in all, your <configSections> section will look something like this:
<configSections>
  <section name="quartz" type="System.Configuration.NameValueSectionHandler, System, Version=1.0.5000.0,Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
  <sectionGroup name="common">
    <section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
  </sectionGroup>
</configSections>
So far all we have done is set up the configuration file to be able to configure both commons logging and log4net from within that one file. Now, let’s configure commons logging to use log4net. Just add this somewhere under the <configuration> element:
<common>
    <logging>
      <factoryAdapter type="Common.Logging.Log4Net.Log4NetLoggerFactoryAdapter, Common.Logging.Log4net">
        <arg key="configType" value="INLINE" />
      </factoryAdapter>
    </logging>
  </common>
This tells commons logging that we are going to log to log4net. Now, all that is left to do is to configure log4net itself. Here is a sample log4net configuration:
<log4net>
   <appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
     <layout type="log4net.Layout.PatternLayout">
       <conversionPattern value="%d [%t] %-5p %l - %m%n" />
     </layout>
   </appender>
   <root>
     <level value="INFO" />
     <appender-ref ref="EventLogAppender" />
   </root>
</log4net>
To wrap up this post, let me point out 2 things to keep in mind when configuring log4net with Quartz.net:
  1. You don’t need to configure log4net in the main application config file. You can load an external log4net configuration file, just as you would if you weren’t using Quartz.Net.
  2. You do need to tell commons logging to use log4net as the logging framework, which is what we did in the <common> section.
You can also read more on configuring commons logging to use log4net from the Common.Logging documentation.

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Getting Started With Quartz.Net Part 5 – Configuring Triggers

In Part 4, we explained how to configure jobs in detail. In this final installment of the series we’ll describe how to configure two kinds of triggers: the CronTrigger and the SimpleTrigger.
In keeping with the previous posts, we will configure the triggers in the quartz_jobs.xml file. Part 4 included a sample configuration of a CronTrigger, so let’s start with this. Here is the xml fragment that we are going to work with:
<trigger>
    <cron>
      <name>PayrollProcessorTrigger</name>
      <group>Payroll</group>
      <description>Trigger payroll</description>
      <misfire-instruction>SmartPolicy</misfire-instruction>
      <volatile>false</volatile>
      <job-name>PayrollProcessor</job-name>
      <job-group>Payroll</job-group>
      <cron-expression>0 * * * * ?</cron-expression>
    </cron>
  </trigger>

Common Properties
The first 3 elements should be familiar to you. They are used to describe and identify the trigger. The trigger is identified by both the name and the group.  You can have triggers with the same name as long as they are not in the same group.
The next element on the list is the misfire-instruction. This element tells the scheduler what it should do if the trigger misfires. A trigger misfires when the scheduler is unable to fire the trigger when it was supposed to be fired. This could be because the scheduler was down or too busy, for example. The two built-in types of misfire instructions are InstructionNotSet, which is the default setting if no misfire instruction is specified and SmartPolicy.  The SmartPolicy instruction is a high level instruction that basically asks each trigger to decide what the “smart” thing to do is.
The Cron trigger provides (in addition to the instructions listed above)  the following MisfireInstruction values: FireOnceNow and DoNothing. For a Cron trigger the SmartPolicy instruction translates to FireOnceNow. The names are pretty descriptive as far as what the scheduler should do.
The SimpleTrigger also provides some additional MisfireInstructions: FireNow, RescheduleNowWithExistingRepeatCount, RescheduleNowWithRemainingRepeatCount,RescheduleNextWithRemainingCount and RescheduleNextWithExistingCount. If you select a SmartPolicy MisfireInstruction for the SimpleTrigger, things aren’t that simple anymore. The documentation explains what will happen as follows:
If the Repeat Count is 0, then the instruction will be interpreted as FireNow. If the Repeat Count is RepeatIndefinitely, then the instruction will be interpreted as RescheduleNowWithRemainingRepeatCount. There is also the following warning: using RescheduleNowWithRemainingRepeatCount with a trigger that has a non-null end-time may cause the trigger to never fire again if the end-time arrived during the misfire time span. Finally, if the Repeat Count is > 0, then the instruction will be interpreted as RescheduleNowWithExistingRepeatCount.
As you can see, it’s really not that simple… However, that covers the MisfireInstruction part. Now it’s time to look at the Volatile property, which so happens to be the same as for the Job and that we discussed in Part 4:
The description of the volatile parameter has a double negative in the documentation description, so I’ll try to rephrase it in a way that is a bit less confusing. If you set the volatile parameter to true, the job will not be persisted in the job store when the scheduler is shut down. If you set the volatile parameter to false, the job will get persisted in the job store. Note, however, that if you are using the AdoJobStore, the job will get persisted regardless of the value of this parameter. Also consider the fact that if you are using the in memory data store… no data will get persisted and you will have to re-schedule all the jobs upon start up.
Next up are the JobName and JobGroup properties, which effectively link the trigger to the job. A trigger can only be assigned to one job and the job’s name and group are needed in order to uniquely identify the job. Make sure these match the name and group of the job you want to schedule.
You can also set the trigger’s start and end times, by adding these elements:
<start-time></start-time>
<end-time></end-time>
Make sure you specify the times in UTC!
Cron Trigger Properties
The last property that we need to provide for a Cron trigger is the Cron expression. This expression follows “mostly” the standard cron syntax, but there are some differences that can cause some frustration, so be sure to look at the documentation. The Quartz.Net cron expression documentation is here and the link also has some examples of the most common expressions.
Simple Trigger Properties
Here is an xml fragment for configuring the simple trigger. We’ll only discuss the last two elements, because the rest of them work just as we described above.
<trigger>
  <simple>
    <name>sampleSimpleTrigger</name>
    <group>sampleSimpleGroup</group>
    <description>Simple trigger to simply fire sample job</description>
    <misfire-instruction>SmartPolicy</misfire-instruction>
    <volatile>false</volatile>
    <job-name>sampleJob</job-name>
    <job-group>sampleGroup</job-group>
    <repeat-count>RepeatIndefinitely</repeat-count>
    <repeat-interval>3000</repeat-interval>
  </simple>
</trigger>
The RepeatCount is used to tell the trigger how many times to fire. You can either specify a number or you can specify RepeatIndefinitely, which basically means the trigger keeps firing over and over again.
The RepeatInterval property sets the time interval at which to repeat the trigger. The example is set in milliseconds.
With this last post I think we have covered pretty much everything that you need to know to set up, configure and run a Quartz.Net server.
Thanks for reading!

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Getting Started With Quartz.Net: Part 4 – Configuring Jobs

  • J
  • Date : April 14, 2009
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Part 3 of this series describes how to configure a job to run on Quartz.Net, but it does not go into detail about what each of the job settings does. This post will cover configuring jobs in detail and will provide some examples of job configurations.
Most of the information we will be covering is available in the documentation for Quartz.Net documentation for JobDetail.
First, let’s take a quick look at how things are organized internally. This will help you understand at a high level how Quartz works inside (from an API point of view), without going into great detail into the object model. I’ll use the folder metaphor to simplify things, but keep in mind that the Quartz.net object model is not completely hierarchical. This folder based image is a simplified representation that you can refer to while reading the explanation below:
20090413-quartzStructure
The highest level item we’ll look at is the scheduler. The scheduler manages pretty much everything, and at a high level, it works with Jobs, or more specifically, JobDetails which it organizes into groups. So, a Scheduler has JobGroups, which in turn contain jobs (JobDetails). Finally, a job can have zero or more triggers. We’re not going to spend too much time looking at triggers (that is the subject of the next post) but, we’ll cover the basics here.
By giving a job a name and a group, you are uniquely identifying it. Within a job group, job names must be unique. If you look at the configuration file we covered in the previous post, the first 2 fields (name and group) are what we are talking about here. The third field, description, is useful for explaining what a job is supposed to do.
Triggers are organized in groups as well, and like jobs, a trigger’s name must be unique within a group. Unlike jobs, triggers can only be assigned to one job. To summarize, while a job can have multiple triggers, a trigger can only have one job.
Now let’s look at the rest of the job parameters, starting with the JobType. As its name states, this is basically the Type (as in .Net Type) that the scheduler should create to run the job. In the xml it is described by first putting the fully qualified type name and then, separated by a comma, the assembly name (without the .dll extension).
The description of the volatile parameter has a double negative in the documentation description, so I’ll try to rephrase it in a way that is a bit less confusing. If you set the volatile parameter to true, the job will not be persisted in the job store when the scheduler is shut down. If you set the volatile parameter to false, the job will get persisted in the job store. Note, however, that if you are using the AdoJobStore, the job will get persisted regardless of the value of this parameter. Also consider the fact that if you are using the in memory data store… no data will get persisted and you will have to re-schedule all the jobs upon start up.
The durable description is easier to understand. Setting this to true means that the job will be kept around even if it doesn’t have any triggers pointing to it. If it is set to false, the job gets deleted if it doesn’t have any triggers pointing to it.
Next up is the recover (RequestsRecovery) parameter. This parameter tells the scheduler whether it should try to recover (re-execute) the job if something goes wrong with the scheduler itself while the job was running.
The last parameter, or list of parameters that we’ll discuss is the JobDataMap. In short, this map is used to pass data to the job. Think of it as a collection of name value pairs that you can consume within your job. In the default quartz_jobs.xml, the data contained in the map is what you would expect to find if you wanted to invoke a command line program: the executable name and the arguments to pass to the executable. For the NativeJob itself, there are 2 parameters that you need to be aware of: the waitForProcess parameter (boolean) and consumeStreams (boolean) .
The WaitForProcess parameter tells the NativeJob whether to wait for the process to finish before considering the Job complete.
The ConsumeStreams parameters should be set to true if your executable produces any output to stderr or stdout. Otherwise, the process might hang. Any output produced by the executable is piped to the event log (if you are using the default configuration).
That’s it for this post. Hopefully this give you a more in depth explanation of how to configure Quartz.Net jobs. In Part 5, we’ll discuss trigger configuration.

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