The Return of the Persistent Quartz Job

Finally I managed to understand the persistent job and make it work reliably: for your stateful job and the trigger volatility should NOT be true. Even setting durability to true can cause problems as it would persist orphan jobs that we may not need. If the intention is to just prevent loss of jobs during system re-starts, it is enough to set requests recovery to true. That's it. Simple is beautiful :).

The Wierd Persistent Quartz Job

I recently faced a problem with getting quartz to persist the jobs in case of a scheduler shut down. Penning down how it got solved (with Ben's help). 

My initial scheduler config looked like this.

Also, when I configured my stateful job, I set volatility and request recovery to true besides putting in job class, name and group. Sadly, the job never-ever persisted when the system re-started. 

Miraculously, this started working fine when config was replaced by this configuration (only scheduler config is different).

Plus when I configured the stateful job, I set durability to true and always put in job class, name and group. Of course you can add what you want to the data map (as long as it is Serializable). 

What I don't understand is that even when I have not set either volatility or request recovery to true, how setting only durability to true takes care of persisting the Job between shutdowns and startups. Whatever it takes to make it work... Quirky but may be helpful to you if you face a similar problem. Cheers.

Setting up Quartz in a Spring-MySQL Environment

If you are using a persistent JobStore in Quartz, you will have to back your spring application with a DB. MySQL can be pretty convenient for local unit testing. Besides the regular spring DataSource config, you need a few more things here and there. I did not find any comprehensive "todo" checklist for MySQL online. So summing up what worked for me.

Using SchedularFactoryBean you can specify a MySQL DataSource and fine-tune it using quartz properties. You can see this in a config file I had published earlier:

XML Config

Besides this, you need to have the following dependencies for sure in your pom if you are using Maven:

POM dependencies

If you are not using maven, the corresponding jars should be in the classpath.

Finally, don't forget to run the SQL script to create tables in your database provided by quartz:

Creating DB Tables for Quartz

The Mysterious Ways of SchedulerFactoryBean

Using Spring framework and Quartz, I wanted to make some dynamic Jobs and triggers. After banging my head and some accidents I finally understood how to use it. The API docs say:

"For dynamic registration of jobs at runtime, use a bean reference to this SchedulerFactoryBean to get direct access to the Quartz Scheduler (org.quartz.Scheduler). This allows you to create new jobs and triggers, and also to control and monitor the entire Scheduler."

What the hell that means, I couldn't figure. Hunting for some examples on the web didn't help either. In one of my posts I have given a link to fine tune SchedulerFactoryBean for static jobs. Picking from there, let us assume you have a Stocks Alert Manager to which you wish to give a spring managed scheduler using your very own SchedulerFactoryBean . Let us assume your stockAlertsManager looks like this:

A Sample StocksAlertManager

Then your bean config should look something like this:

Bean Config to use SchedulerFactoryBean dynamically

If you have not noticed, the scheduler property of StockAlertsManager is of type org.quartz.impl.StdScheduler but in the bean config I have set it to the reference of our all-powerful SchedulerFactoryBean. Despite of the mismatch in types your spring application will not complain and initialize the scheduler property nicely. Even when SchedulerFactoryBean does not in any way extend StdScheduler or implement Scheduler . Wierd, counter-intuitive but works. Re-visiting the API doc:

"For dynamic registration of jobs at runtime, use a bean reference to this SchedulerFactoryBean to get direct access to the Quartz Scheduler (org.quartz.Scheduler). This allows you to create new jobs and triggers, and also to control and monitor the entire Scheduler."

Well, they literally meant it! Who would have thought?!

Quartz and Spring

For scheduling purposes one can use Quartz with Spring. The basic usage can be learnt by going through the quartz tutorial and spring documentation on scheduling .

However when it came to using advanced usage like configuring job stores, I had a little difficulty finding stuff. A particular entry in the spring forum was really useful. These three resources were able to take care of my reasonably complex needs for scheduling. Hope they are of some use to you too.