Non-clustered Quartz Scheduler: Instantiating and starting scheduler on application startup... is this safe for multiple machines?

Question

My application currently instantiates and starts a default scheduler during application startup using:

@Override
public void contextInitialized(ServletContextEvent arg0) {
    try {   
        Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
        scheduler.start();
    } catch (SchedulerException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

This logic runs on a cloud machine as well as on local development machines, and quartz.properties is currently set to non-clustering mode. The application is also using JDBC Job Store.

I'm concerned about having one scheduler instance for each machine- please give me recommendations on how to manage Quartz Scheduler on multiple machines. Does this use case require clustering?

I scheduled a test trigger to run every minute. While there haven't been duplicate job executions, I've noticed a few missed firings that were never counted as misfires.

can you elaborate your use case? Its not very clear from what you are describing. Does your use case need multiple instances to share the load by forming a cluster or you are just looking for persistence support? Do each of your node manage their own workload? — Srinivas
@Srinivas after playing around with different configurations, I've found a setup that works for the app. I'll write more about it in an answer below. — plsplox

plsplox plsplox · Accepted Answer · 2017-10-20T14:42:40

I played around with the configuration and settings, and found a setup that works for my application. The app servers serve web resources from a cluster configuration; my mistake was starting a non-clustered scheduler instance in each app server.

At the moment, I don't think this application needs multiple machines are needed to handle scheduled jobs just yet. Also, I haven't figured out how to synchronize system times on our cloud servers, which is a requirement for Quartz's clustering feature.

I ended up dedicating a single non-clustered machine that starts one scheduler instance. This configuration works as expected, and the odd bugs have disappeared (unacknowledged misfires, etc.).

Non-clustered Quartz Scheduler: Instantiating and starting scheduler on application startup... is this safe for multiple machines?

1 Answers