An extremely easy way to perform background processing in Java. Backed by persistent storage. Open and free for commercial use.
This release introduces a slew of new features such as Carbon Aware Job Processing; a new feature that optimizes job execution based on grid carbon intensity, helping reduce your application’s environmental impact by running jobs when cleaner energy is available.
For instance, suppose you have a daily recurring job that generates invoice PDF files and sends them out to customers. That job can be configured by using a simple cron, e.g. 0 5 * * *. Each early morning at 5AM, it will start to process data. But what if two hours later would be a better moment to reduce the CO2 footprint of the application?
Instead of scheduling jobs like this:
BackgroundJob.scheduleRecurrently("0 5 * * *", () -> pdfService.generate());
You can now do this:
BackgroundJob.scheduleRecurrently("0 5 * * * [PT1H/PT3H]",
() -> pdfService.generate());
// or
BackgroundJob.scheduleRecurrently(CarbonAware.dailyBetween(4, 8),
() -> pdfService.generate());
// or
BackgroundJob.scheduleRecurrently(CarbonAware.cron("0 5 * * *", Duration.of(1, HOURS), Duration.of(3, HOURS)),
() -> pdfService.generate());
The configured margin [from, to] adds slack to the schedule time of the job. Depending on the forecast put out by the data provider, the job can be enqueued an hour sooner ([PT1H) or at most three hours later (/PT3H]). JobRunr comes equipped with multiple expressive APIs that help ease the configuration of these Carbon Aware Jobs, by using the CarbonAware class or the CarbonAwarePeriod class for fire-and-forget jobs.
As soon as recurring jobs with a Carbon Aware margin are scheduled, a job is created ahead of time in a “Pending” state, waiting to be scheduled depending on the Carbon Intensity forecast. Once JobRunr figures out when exactly to run the job, it will set a scheduled time to move on to the next states: “Scheduled”, and when it is time to execute, “Enqueued” and “Processing”.
There are also reference links on the website for more information on how to use Carbon Aware Jobs.
Add this block in pom.xml to use JobRunr v8:
<!-- JobRunr core (v8) -->
<dependency>
<groupId>org.jobrunr</groupId>
<artifactId>jobrunr</artifactId>
<version>${jobrunr.version}</version>
</dependency>
<!-- Jackson (JobRunr needs a Json provider) -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.15.2</version>
</dependency>
And, then we can configure the jobrunr.
package com.example;
import org.jobrunr.configuration.JobRunr;
import org.jobrunr.scheduling.JobScheduler;
import org.jobrunr.storage.InMemoryStorageProvider;
import org.jobrunr.scheduling.BackgroundJob;
import org.jobrunr.scheduling.carbonaware.CarbonAware;
import org.jobrunr.server.BackgroundJobServerConfiguration;
import org.jobrunr.server.carbonaware.CarbonAwareJobProcessingConfiguration;
public class App {
public static void main(String[] args) throws Exception {
// Configure JobRunr with in-memory storage (good for testing/demo)
JobScheduler jobScheduler = JobRunr.configure()
.useStorageProvider(new InMemoryStorageProvider())
.useBackgroundJobServer(
BackgroundJobServerConfiguration.usingStandardBackgroundJobServerConfiguration()
// enable & configure Carbon Aware processing (area code = BE for Belgium)
.andCarbonAwareJobProcessingConfiguration(
CarbonAwareJobProcessingConfiguration
.usingStandardCarbonAwareJobProcessingConfiguration()
.andAreaCode("BE") // set to your datacenter / region (ISO 3166-2)
)
)
.useDashboard() // launches dashboard (default port 8000)
.initialize()
.getJobScheduler();
// 1) Simple fire-and-forget hello
jobScheduler.enqueue(() -> System.out.println("Hello from JobRunr!"));
// 2) Carbon-aware recurring job (daily, but allow a margin)
// Use the expressive CarbonAware API: dailyBetween(2, 8) => schedule somewhere between 02:00 and 08:00 local time,
// JobRunr will select the best (lowest-carbon) moment in that interval.
jobScheduler.scheduleRecurrently(
"carbon-hello", // job id
CarbonAware.dailyBetween(2, 8), // preferred daily time + margin window
() -> System.out.println("Carbon-aware Hello World!"));
System.out.println("Dashboard should be available at http://localhost:8000");
// keep JVM alive so background server & dashboard keep running
Thread.currentThread().join();
}
}
Complete example is attached in HelloCarbonAware directory.
Run the below bash command to run the example:
$ mvn -DskipTests compile exec:java -Dexec.mainClass="com.example.App"
Dashboard should be available at http://localhost:8000
Hello from JobRunr!