Prevent Duplicate Work with Cache::withoutOverlapping()

Cache::withoutOverlapping()

Imagine an API endpoint that starts an expensive operation:

public function generateReport()
{
    // Generate a large report...
}

If two requests arrive at almost the same time, both requests may start the same operation.

This can result in:

• Duplicate processing
• Unnecessary database queries
• Multiple files being generated
• Conflicting updates

Laravel provides a simple solution for this.

Use Cache::withoutOverlapping()

use Illuminate\Support\Facades\Cache;
Cache::withoutOverlapping('generate-report', function () {
    // Generate report...
});

Laravel creates an atomic lock for the given key. If another execution tries to acquire the same lock while the first one is running, it won't execute concurrently.

Add a Lock Duration

You can control how long the lock should remain valid:

Cache::withoutOverlapping(
    'generate-report',
    function () {
        // Generate report...
    },
    lockFor: 120
);

Here, the lock can remain active for up to 120 seconds.

Control How Long to Wait

You can also specify how long another execution should wait for the lock:

Cache::withoutOverlapping(
    'generate-report',
    function () {
        // Generate report...
    },
    lockFor: 120,
    waitFor: 5
);

The second execution can wait up to 5 seconds for the lock before Laravel gives up.

Real-World Example

Suppose your admin panel has a button to synchronize products from an external API.

Instead of allowing multiple clicks to start multiple synchronizations:

Cache::withoutOverlapping('product-sync', function () {
    $this->syncProducts();
});

Now only one product synchronization can run at a time.