I have one #Scheduler job which runs on multiple servers in a clustered environment. However I want to restrict the job to run in only in one server and other servers should not run the same job once any other server has started it .
I have explored Spring Batch has lock mechanism using some Database table , but looking for any a solution only in spring task:scheduler.
I had the same problem and the solution what I implemented was a the Lock mechanism with Hazelcast and to made it easy to use I also added a proper annotation and a bit of spring AOP for that. So with this trick I was able to enforce a single schedule over the cluster done with a single annotation.
Spring Batch has this nice functionality that it would not run the job with same job arguments twice.
You can use this feature so that when a spring batch job kicks start in another server it does not run.
Usually people pass a timestamp as argument so it will by pass this logic, which you can change it.
Related
There are three instances of the application on the server. but we want to execute the cronjob schedular logic on one instance of the application.
Using Spring-data, couchbase repository with couchbase database. is there any simple solution to my problem please suggest me. thanks in advance . i suffer from this problem from many days.
Facing similar situations with multiple spring boot instances, we schedule the cron externally, this can be a simple cron script that executes a curl, or a specific external scheduler app/instance. Your load balancer will pick an instance to run on.
You could also consider using quartz or shedlock with couchbase to manage without external trigger.
I have a business logic already developed in spring boot that needs to be run once in every 60 days. I'm little confused on whether convert it to spring batch or use scheduler annotation.
What all factors should I consider to assess the same? Does either of them has any performance upper-hand over the other?
I'm new to the scheduler-batch concept and this is my first time work on the same.
How to assess whether to use spring batch or scheduler in application?
Spring Batch is not a scheduler, so it's not an either or question. You can use both, for example use a scheduler to schedule a Spring Batch job to run at a given time.
The question you should be asking is: is it worth transforming the business logic you already developed in spring boot in a Spring Batch job to benefit from what Spring Batch offers (the whole app could remain a boot app).
As a side note, since your job needs to be run every 60 days, using #Scheduled means you would have a JVM running for two months to run a job. Unless you are planning to use the same JVM for other things in the meantime, this would be an inefficient use of resources. Other scheduling mechanisms like cron is more appropriate in this case.
When I use spring task handle a simple sync job! But when I deploy multi-node, how I make sure the cron job just run one time.
Maybe you say that:
1. Use distributed-lock control a flag before the crob job run.
2. Integrated quartz cluster function.
But I hope spring task #EnableScheduling can add a flag argument, so as we can set a flag when launch app.
We are using https://github.com/lukas-krecan/ShedLock with success, zookeeper provider in particular.
Spring boot, in a nutshell, doesn't allow any type of coordination between multiple instances
of the same microservice.
All the work of such a coordination is done by the third parties that spring boot gets integrated with.
One example of this is indeed a #Scheduled annotation.
Another is DB migration support via flyway.
When many nodes start and the migration has to be done, flyway is responsible to lock the migration table by itself, spring boot has nothing to do with it.
So, bottom line, there is no such support and all options that you've raised can work.
I'm willing to build a synchronization service in Java. The use case is, that i'm fetching data from an exchange-service (via Exchange Web Services), normalize the data a bit (process probably) and then write it to a backend via GraphQL. I already had a look around the spring modules, but am not quite sure what modules to use. I found spring batch and spring quartz.
The synchronization will have to trigger all X seconds, fetch information from the Exchange, look what's in the backend already and update what's needed.
Do you guys have any suggestions? I started implementing this whole thing in nodejs before, but as it has to run on both, Windows Servers and Docker/Linux, it has been a real pain to keep it running smooth (mostly because bundling nodejs to an application for Windows is pain).
Difference between Spring Batch & Quartz:
Spring Batch and Quartz have different goals. Spring Batch provides functionality for processing large volumes of data and Quartz provides functionality for scheduling tasks.
So Quartz could complement Spring Batch, A common combination would be to use Quartz as a trigger for a Spring Batch job using a Cron expression.
Conclusion : So basically Spring Batch defines what should be done, Quartz defines when it should be done.
Quartz is a scheduling framework. Like "execute something every hour or every last friday of the month"
Spring Batch is a framework that defines that "something" that will be executed.
You can define a job, that consists of steps. Usually a step is something that consists of item reader, optional item processor and item writer, but you can define a custom stem. You can also tell Spring batch to commit on every 10 items and a lot of other stuff.
You can use Quartz to start Spring Batch jobs.
Recommended for your use case :
Quartz scheduling as you want trigger after specific interval.
Reference :https://projects.spring.io/spring-batch/faq.html
Part of my job is to poll DB for a specific result status and only after that I can continue with next job's steps.
Is it recommended to stop the job's process while doing polling in one of the steps(tasklet I guess) ?
Polling the DB for a specific result sounds like a situation where you need a scheduler.
Spring-batch assumes the scheduling of the job is done from outside it's scope.
You can use #Scheduled spring annotation if you want to keep all inside spring configuration or use an external tool like this.
If you have more complex situations, have a look at Spring Batch Integration.