I am looking at Spring Batch 2.0 to implement a pipeline process. The process is listening to some event, and needs to perform a set of transformation steps base on the event type and its content.
Spring batch seem to be a great fit. However, going through the documentation, every example have them job and its steps configured in xml. Does the framework support creating jobs during run-time and configuring the steps dynamically?
the job configuration itself is set before the job runs, but it is possible to create a flexible job configuration with conditional flows
you can't just change the job configuration while the job runs, but between jobs its easy to replace the configuration
Addon for Michael answer:
Do you want to create a flow from beginning to end completely dynamically or you want to have some dynamics at certain point?
As Spring Batch instantiates jobs (will all internals) from XML configuration, that means all necessary beans have setters/getters and you can create the Job from empty page. This is long and bug-prone way (you need to create FlowJob as in JobParserJobFactoryBean goes, then SimpleFlow then StepState then TaskletStep as in SimpleStepFactoryBean and bind them together).
I think the alternative to XML flows could be your coded logic. For String Batch it will look as one step, but with custom implementation and subflow. See <tasklet ref="myCleverTasklet" /> example in Example Tasklet Implementation.
Related
I have to run a schduler(any schduled jobs) where i have to fetch 300,000-400,000 in average twice daily from database and apply business logics one by one where each process requests to thirdparty which takes 3-4 seconds to respond.
what are alternates of spring batch processing to process such huge data in efficient ways?
Note: fetched data are not static, data may vary everyday.
May be #Scheduled annotation can help you out.
You can use the Spring Batch schedular. It execute spring batch jobs periodically on fixed schedule using some cron expression passed to Spring TaskScheduler
To configure, batch job scheduling is done in two steps:
Enable scheduling with #EnableScheduling annotation.
Create method annotated with #Scheduled and provide recurrence details using cron job. Add the job execution logic inside this method.
Here is the link of an example : https://howtodoinjava.com/spring-batch/job-scheduler-example/
How can I use DefaultJobParametersValidator in a Java-based Spring Batch Application? Should I call it manually in a Tasklet? I cannot find any examples that does not used an xml configuration.
A JobParametersValidator is used to validate job parameters before every job execution. You do not call it manually, you need to register it in your job definition and Spring Batch will call it for you (this is how frameworks work). The DefaultJobParametersValidator will be used by default if you do not specify a custom validator.
The JobParametersValidator section in the reference documentation shows how to register a job parameter validator in both XML and Java configuration styles.
I am looking for a way to store system processes / tasks that the application will then execute according to the specified system-wide conditions. The point is that the system should check the input variables and trigger specific actions in the system according to the rules of the process.
I am probably looking for some form of meta-language that I can write rules / actions and that can be programmed to start and stop based on input system parameters.
In what format record such processes?
How to parse these jobs?
What design patterns apply to this?
Are there any existing solutions on this use-case?
Which Java libraries to use for this.
If anything is unclear, I will gladly complete the question.
Thank you.
You could try Spring Batch. It introduces it's own domain language for jobs and allows configure them both using XML or java.
Here are couple of examples from their reference guide.
XML config:
<job id="footballJob">
<step id="playerload" next="gameLoad"/>
<step id="gameLoad" next="playerSummarization"/>
<step id="playerSummarization"/>
</job>
Java config:
#Bean
public Job footballJob() {
return this.jobBuilderFactory.get("footballJob")
.start(playerLoad())
.next(gameLoad())
.next(playerSummarization())
.end()
.build();
}
Spring Batch provides functionality for repeating or retrying failed job steps as well as for parallel steps execution.
For some tasks also Apache Camel can be used. It although provides its own DSL and both XML and Java configuration options.
Both frameworks provide abstractions for description of sequence of actions, which should be done during the job. Apache Camel is more convenient for jobs which require some integration tasks (sending messages in JMS queues, calling REST- or Web- services, sending emails etc). Advantage of Spring Batch is ability to configure application behavior in case of an error or temporary inaccessibility of a service, which should be called (repeat / retry mechanisms). Both frameworks can be integrated with each other: you can call Spring Batch jobs from Apache Camel routes or initiate Apache Camel routes from Spring Batch jobs.
Most complicated solution would be usage of some BPMN engine (e.g. Camunda, Apache Activiti, jBPMN), but that probably would be an overkill.
I have an existing java application that uses spring and hibernate and is deployed in AWS EBS environment. I now have a need to support thousands of light weight but persistent jobs and am considering using quartz for managing those jobs.
First, does anybody who has done this before see any issues or has word of wisdom. Second, I am looking for samples of managing a separate bean in this application that would start the scheduler so that it could run jobs, add more jobs or delete jobs that are not needed anymore. All the samples that I have seen so far use xml configuration. My environment does not have any xml configuration. Are there any samples that I can use to accomplish this in a configuration-less spring environment.
Thanks for your help in advance.
Waqar
I think Camel can help you
http://camel.apache.org/quartz.html
http://camel.apache.org/cronscheduledroutepolicy.html
CronScheduledRoutePolicy startPolicy = new CronScheduledRoutePolicy();
startPolicy.setRouteStartTime("*/3 * * * * ?");
from("direct:start")
.routeId("testRoute").routePolicy(startPolicy).noAutoStartup()
.to("mock:success");
Has "spring batch" ability to limit run jobs without manual check job status? Job can be different or instances of one job. Need something like configurable property.
No. The only way is to manually check via JobExplorer interface or directly query jobs metadata tables