How to run a scheduled job every 1 minute , and automatically start the re-scheduled automatically? [duplicate]

Question

How to run a scheduled job every 1 minute , and automatically start the re-scheduled automatically again and again same process. I am trying this example below way. But it can't reschedule automatically and time interval also not clear. Could you please give me an example another way.

Global class SchedulebatchAccountUpdate1 Implements Schedulable {
    global void execute(SchedulableContext sc) {
    batchAccountUpdate1 c = new batchAccountUpdate1();
    Database.executeBatch(c);
    }

 Public static void SchedulerMethod() {   
     String sch = '0 0 * * * ?';
    system.schedule('My Jobs scheduled name', sch, new SchedulebatchAccountUpdate1());

   }
}

Answer 1

It is not possible. Scheduled classes are queued, and sometimes they can take longer than a minute to run. This means that your code wouldn't be accurate from the start. Also scheduled classes with little time between executions can cause bugs in your organization (I lost two sandboxes because a class would get stuck and wouldn't be able to be edited or executed again).

You should get another way to do what you want to do. If you absolutely need to do this by the minute, while your users are logged in the system, might I suggest to call your code not with a scheduled class but with a custom Javascript on the sidebar? I've done this before and it works just fine (although it had a bigger interval).

Answer 2

Here's an example of how you'd do the above using a queueable only you'd need to include the details of the Execute method that's in your BatchUpdateAccount1 which aren't shown. What's below is based on code from Dan Appleman's Advanced Apex Programming 3rd Edition.

public without sharing class AsyncAppleman 
    implements queueable {

    public void execute(QueueableContext context)
    {
        // you want a class that allows you turn your queueable on and off using custom settings 
        // which is what the below references
        if(!AppConfigSupport.appEnabled) return; // On/off switch

        // Your execute method here... 


        Integer allowedgetQueueableJobs = 
            Limits.getLimitQueueableJobs() - Limits.getQueueableJobs();

        if(allowedgetQueueableJobs()<=0) 
           return;

        if(allowedgetQueueableJobs > 0)
            try
            {
                system.enqueueJob(new GoingAsync3());
            } catch(Exception ex)
            {
                // Alternate chaining mechanism such as schedule your batch job. Check limits for schedulables first
            }

    }


}