Laravel Job Batching

Laravel's job batching feature allows you to group multiple jobs into a batch and perform actions when the batch completes, fails, or progresses. This is particularly useful for tasks like processing large datasets or executing dependent jobs. 

 Defining Batchable Jobs 

 To make a job batchable, include the Illuminate\Bus\Batchable trait in your job class. This provides access to the batch() method, which allows the job to interact with its batch. For example: 

 

 

 

 

 namespace App\Jobs; 

 

 use Illuminate\Bus\Batchable; 

 use Illuminate\Contracts\Queue\ShouldQueue; 

 use Illuminate\Foundation\Queue\Queueable; 

 

 class ImportCsv implements ShouldQueue 

 { 

 use Batchable, Queueable; 

 

 public function handle(): void 

 { 

 if ($this->batch()->cancelled()) { 

 // Stop processing if the batch is cancelled 

 return ; 

 } 

 

 // Process the CSV data 

 } 

 } 

 

 

 

 

 

 

 

 

 

 Dispatching Job Batches 

 You can dispatch a batch of jobs using the Bus::batch() method. This method also supports completion callbacks like then , catch , and finally : 

 

 

 

 

 

 

 

 

 

 use App\Jobs\ImportCsv; 

 use Illuminate\Bus\Batch; 

 use Illuminate\Support\Facades\Bus; 

 

 $batch = Bus::batch([ 

 new ImportCsv(1, 100), 

 new ImportCsv(101, 200), 

 new ImportCsv(201, 300), 

 ])->then( function (Batch $batch) { 

 // All jobs completed successfully 

 })-> catch ( function (Batch $batch, Throwable $e) { 

 // Handle the first job failure 

 })-> finally ( function (Batch $batch) { 

 // The batch has finished executing 

 })->dispatch(); 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Monitoring and Managing Batches 

 Laravel provides tools to inspect and manage batches: 

 

 

 

 

 

 

 

 

 

 $batch->progress() returns the completion percentage. 

 

 

 $batch->cancel() cancels the batch. 

 

 

 $batch->failedJobs retrieves the number of failed jobs. 

 

 

 

 

 

 

 

 

 

 You can also retrieve a batch by its ID using Bus::findBatch($batchId) . 

 Adding Jobs Dynamically 

 You can add jobs to an existing batch from within a batch job using the add() method: 

 

 

 

 

 

 

 

 

 

 

 $this->batch()->add([ 

 new ImportCsv(401, 500), 

 new ImportCsv(501, 600), 

 ]); 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Batch Failures and Pruning 

 When a job in a batch fails, the catch callback is triggered. By default, a failed job cancels the entire batch, but you can override this behavior using the allowFailures() method. To clean up old batch records, schedule the queue:prune-batches Artisan command. 

 Important Considerations 

 

 

 

 

 

 

 

 

 

 Database Migration : Ensure you have a job_batches table by running php artisan make:queue-batches-table and migrating it. 

 

 

 Callbacks : Avoid using $this in batch callbacks as they are serialized. 

 

 

 Batch Naming : Use the name() method to assign a name for better debugging in tools like Horizon. 

 

 

 

 

 

 

 

 

 

 Laravel's job batching simplifies handling complex workflows by grouping jobs and providing robust tools for monitoring and managing their execution.