When RoadRunner starts workers, they operate in daemon mode. In this mode, you need to reload the server every time you make changes to your codebase.
One way to reload the server is using the console command:
{% code %}
./rr reset{% endcode %}
This command is also helpful when you need to restart a remote RoadRunner server using a local RoadRunner client.
For example, you can use this command to restart workers inside a Docker container. To do this, you need to configure the RoadRunner server to handle external RPC requests by adding the following lines to your configuration file:
{% code title=".rr.yaml" %}
rpc:
listen: tcp://:6001{% endcode %}
{% hint style="info" %}
You must also forward/expose port 6001 in your Docker container to be able to use this feature.
{% endhint %}
Now when you run the command, the RoadRunner client sends an RPC request to the running server.
{% hint style="warning" %}
Ensure the RPC host and port used by the RoadRunner client (in .rr.yaml) match those used by the RoadRunner server. By default, the client uses 127.0.0.1:6001.
{% endhint %}
It can be a time-consuming and tedious process to restart workers manually, especially during the development phase of a project. To address this issue, RoadRunner provides a debug mode that automatically restarts workers after each handled request, allowing developers to make changes to their codebase without having to manually reload the server each time.
To enable debug mode, set the pool.debug option to true in the desired plugin section that has a worker pool:
{% code title=".rr.yaml" %}
http:
pool:
debug: true
num_workers: 4{% endcode %}
Or, if you have only the debug option in the pool section, you can use the short syntax:
{% code title=".rr.yaml" %}
http:
pool.debug: true{% endcode %}
{% hint style="info" %}
Every plugin in RoadRunner that creates workers has a pool section in which you can activate debug mode.
{% endhint %}
{% hint style="warning" %}
When using the pool.debug option in RoadRunner, it is important to note that settings in the pool section will work
differently. All options will be ignored (supervisor, max_jobs, num_workers, etc.). This is because, in debug
mode, RoadRunner does not create a worker at startup. Instead, it waits for requests to come in and creates workers
accordingly. After the response, RoadRunner stops and removes the worker.
When you send multiple parallel requests to RoadRunner, it creates the same number of workers to handle those requests simultaneously.
Similarly, when you use the Jobs plugin and the Jobs consumers, every consumed message creates a worker to handle that message. The number of workers is based on the number of messages consumed.
This enables you to make changes to your codebase and reload it automatically. {% endhint %}
{% hint style="warning" %}
Note that in the Temporal plugin, pool is actually called activities. All other pool options are the same. For example, pool.num_workers is activities.num_workers.
{% endhint %}
In RoadRunner, you can send a stop command from the worker to the parent server to force process destruction. When
this happens, the job/request will be automatically forwarded to the next worker in the queue.
You can use this feature to implement max_jobs control on the PHP side. This can be useful for controlling memory
usage inside the PHP script or for managing long-running tasks that need to be periodically restarted.
{% code title="worker.php" %}
<?php
use Spiral\RoadRunner;
use Nyholm\Psr7;
include "vendor/autoload.php";
$worker = RoadRunner\Worker::create();
$psrFactory = new Psr7\Factory\Psr17Factory();
$worker = new RoadRunner\Http\PSR7Worker($worker, $psrFactory, $psrFactory, $psrFactory);
$count = 0;
while ($req = $worker->waitRequest()) {
try {
$rsp = new Psr7\Response();
$rsp->getBody()->write('Hello world!');
$count++;
if ($count > 10) {
$worker->getWorker()->stop();
return;
}
$worker->respond($rsp);
} catch (\Throwable $e) {
$worker->getWorker()->error((string)$e);
}
}{% endcode %}
As you can see in the example above, we send a stop command after handling 10 requests, to force process destruction.
This ensures that the script does not consume too much memory and avoids any potential memory leaks.