Job chaining and batching in Laravel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to chain two jobs in Laravel.

Laravel

$job1->[1]([$job2]);

Drag options to blanks, or click blank then click option'

Achain

Bdispatch

Cqueue

Dbatch

Attempts:

3 left

💡 Hint

Common Mistakes

Using dispatch instead of chain will run jobs independently.

Using batch is for grouping jobs, not chaining.

In Laravel, the chain method is used to run jobs one after another.

2fill in blank

medium

Complete the code to create a batch of jobs in Laravel.

Laravel

Bus::[1]([$job1, $job2])->dispatch();

Drag options to blanks, or click blank then click option'

Achain

Bdispatch

Cbatch

Dqueue

Attempts:

3 left

💡 Hint

Common Mistakes

Using chain instead of batch will run jobs sequentially, not in parallel.

Using dispatch alone does not create a batch.

The batch method creates a batch of jobs that run in parallel.

3fill in blank

hard

Fix the error in the job chaining code by completing the blank.

Laravel

dispatch(new JobOne())->[1]([new JobTwo()]);

Drag options to blanks, or click blank then click option'

Abatch

Bchain

Cqueue

Ddispatch

Attempts:

3 left

💡 Hint

Common Mistakes

Using batch instead of chain causes jobs to run in parallel, not sequentially.

Calling dispatch again after dispatch causes errors.

The chain method must be used after dispatching the first job to chain the next jobs.

4fill in blank

hard

Fill both blanks to create a batch with a then callback.

Laravel

Bus::[1]([$job1, $job2])->[2](function () {
    // All jobs completed
})->dispatch();

Drag options to blanks, or click blank then click option'

Abatch

Bchain

Cthen

Dqueue

Attempts:

3 left

💡 Hint

Common Mistakes

Using chain instead of batch for grouping jobs.

Using queue instead of then for the callback.

Use batch to create the batch and then to add a callback after all jobs finish.

5fill in blank

hard

Fill all three blanks to create a batch with a catch callback and a name.

Laravel

Bus::[1]([$job1, $job2])
    ->[2](function (Batch $batch, Throwable $e) {
        // Handle failure
    })
    ->name('[3]')
    ->dispatch();

Drag options to blanks, or click blank then click option'

Achain

Bcatch

Cmy-batch

Dbatch

Attempts:

3 left

💡 Hint

Common Mistakes

Using chain instead of batch for grouping jobs.

Using then instead of catch for error handling.

Not providing a batch name string.

Use batch to create the batch, catch to handle failures, and name to assign a batch name.

Practice

1. What is the main difference between job chaining and job batching in Laravel?

easy

A. Job chaining is for database tasks only; job batching is for email tasks only.

B. Job chaining runs jobs in parallel; job batching runs jobs sequentially.

C. Job chaining runs jobs one after another; job batching runs jobs together and tracks progress.

D. Job chaining requires manual tracking; job batching does not track progress.

Solution

1. Step 1: Understand job chaining

   Job chaining runs jobs one after another in a specific order.

2. Step 2: Understand job batching

   Job batching runs many jobs together and tracks their progress as a group.

3. Final Answer:

   Job chaining runs jobs one after another; job batching runs jobs together and tracks progress. -> Option C

4. Quick Check:

   Job chaining = sequential, Job batching = grouped with progress [OK]

Hint: Chaining = sequence; batching = group with progress tracking [OK]

Common Mistakes:

• Confusing parallel and sequential execution
• Thinking batching runs jobs one by one
• Assuming chaining tracks progress automatically

2. Which of the following is the correct syntax to chain two jobs JobA and JobB in Laravel?

easy

A. JobA::chain([new JobB])->dispatch();

B. JobA::dispatch()->chain([JobB]);

C. dispatch(new JobA)->chain(new JobB);

D. dispatch(new JobA)->chain([new JobB]);

Solution

1. Step 1: Recall chaining syntax

   In Laravel, chaining jobs uses dispatch(new JobA)->chain([new JobB]).

2. Step 2: Check options for correct method calls

   dispatch(new JobA)->chain([new JobB]); matches the correct syntax with dispatch(new JobA)->chain([new JobB]);.

3. Final Answer:

   dispatch(new JobA)->chain([new JobB]); -> Option D

4. Quick Check:

   dispatch + chain array = correct chaining syntax [OK]

Hint: Use dispatch(new Job)->chain([jobs]) for chaining [OK]

Common Mistakes:

• Calling chain() on the job class instead of dispatch
• Passing a single job without array to chain()
• Using incorrect method order

3. Given the following code, what will be the output in the logs if all jobs succeed?

Bus::batch([
    new Job1(),
    new Job2(),
    new Job3()
])->then(function () {
    Log::info('Batch completed successfully');
})->dispatch();

medium

A. Logs 'Batch completed successfully' immediately after dispatch.

B. Logs 'Batch completed successfully' after all jobs finish.

C. No logs will be created because then() is not supported.

D. Logs 'Batch failed' if any job fails.

Solution

1. Step 1: Understand batch then() callback

   The then() callback runs after all jobs in the batch succeed.

2. Step 2: Analyze the code behavior

   Since all jobs succeed, the callback logs 'Batch completed successfully' after finishing.

3. Final Answer:

   Logs 'Batch completed successfully' after all jobs finish. -> Option B

4. Quick Check:

   Batch then() runs after success [OK]

Hint: then() runs after all batch jobs succeed [OK]

Common Mistakes:

• Thinking then() runs immediately after dispatch
• Assuming then() runs on failure
• Believing no logs are created

4. Identify the error in this job chaining code:

dispatch(new JobA)->chain(new JobB);

medium

A. chain() expects an array of jobs, not a single job instance.

B. dispatch() cannot be used with chaining.

C. JobB must be dispatched separately before chaining.

D. JobA must be a queued job class, not a job instance.

Solution

1. Step 1: Check chain() parameter requirements

   The chain() method requires an array of job instances.

2. Step 2: Analyze the code

   The code passes a single job instance new JobB without wrapping it in an array.

3. Final Answer:

   chain() expects an array of jobs, not a single job instance. -> Option A

4. Quick Check:

   chain() needs array of jobs [OK]

Hint: Always pass an array to chain(), even for one job [OK]

Common Mistakes:

• Passing a single job without array to chain()
• Trying to dispatch chained jobs separately
• Confusing dispatch and chain usage

5. You want to run three jobs JobX, JobY, and JobZ where JobY should only run after JobX completes, but JobZ can run anytime in parallel. Which Laravel approach correctly handles this?

hard

A. Use job chaining for JobX and JobY, and dispatch JobZ separately.

B. Use job batching for all three jobs together.

C. Chain JobX, JobY, and JobZ in one chain to run sequentially.

D. Dispatch all three jobs separately without chaining or batching.

Solution

1. Step 1: Understand job dependencies

   JobY depends on JobX finishing first, so they must run sequentially.

2. Step 2: Consider JobZ's independence

   JobZ can run anytime, so it should run separately in parallel.

3. Step 3: Choose correct Laravel approach

   Use chaining for JobX and JobY, and dispatch JobZ separately to run in parallel.

4. Final Answer:

   Use job chaining for JobX and JobY, and dispatch JobZ separately. -> Option A

5. Quick Check:

   Chain dependent jobs, dispatch independent jobs separately [OK]

Hint: Chain dependent jobs; dispatch independent jobs separately [OK]

Common Mistakes:

• Batching all jobs when order matters only for some
• Chaining all jobs forcing sequential run
• Ignoring job dependencies