Sidekiq.rs (aka rusty-sidekiq)

This is a reimplementation of sidekiq in rust. It is compatible with sidekiq.rb for both submitting and processing jobs. Sidekiq.rb is obviously much more mature than this repo, but I hope you enjoy using it. This library is built using tokio so it is async by default.

The Worker

This library uses serde to make worker arguments strongly typed as needed. Below is an example of a worker with strongly typed arguments. It also has custom options that will be used whenever a job is submitted. These can be overridden at enqueue time making it easy to change the queue name, for example, should you need to.

#[derive(Clone)]
struct PaymentReportWorker {
    logger: slog::Logger,
}

impl PaymentReportWorker {
    fn new(logger: slog::Logger) -> Self {
        Self { logger }
    }

    async fn send_report(&self, user_guid: String) -> Result<(), Box<dyn std::error::Error>> {
        // TODO: Some actual work goes here...
        info!(self.logger, "Sending payment report to user"; "user_guid" => user_guid);

        Ok(())
    }
}

#[derive(Deserialize, Debug, Serialize)]
struct PaymentReportArgs {
    user_guid: String,
}

#[async_trait]
impl Worker<PaymentReportArgs> for PaymentReportWorker {
    // Default worker options
    fn opts() -> sidekiq::WorkerOpts<Self> {
        sidekiq::WorkerOpts::new().queue("yolo")
    }

    // Worker implementation
    async fn perform(&self, args: PaymentReportArgs) -> Result<(), Box<dyn std::error::Error>> {
        self.send_report(args.user_guid).await
    }
}

Creating a Job

There are several ways to insert a job, but for this example, we'll keep it simple. Given some worker, insert using strongly typed arguments.

PaymentReportWorker::perform_async(
    &mut redis,
    PaymentReportArgs {
        user_guid: "USR-123".into(),
    },
)
.await?;

You can make custom overrides at enqueue time.

PaymentReportWorker::opts()
    .queue("brolo")
    .perform_async(
        &mut redis,
        PaymentReportArgs {
            user_guid: "USR-123".into(),
        },
    )
    .await?;

Or you can have more control by using the crate level method.

sidekiq::perform_async(
    &mut redis,
    "PaymentReportWorker".into(),
    "yolo".into(),
    PaymentReportArgs {
        user_guid: "USR-123".to_string(),
    },
)
.await?;

See more examples in examples/demo.rs.

Starting the Server

Below is an example of how you should create a Processor, register workers, include any custom middlewares, and start the server.

// Redis
let manager = sidekiq::RedisConnectionManager::new("redis://127.0.0.1/").unwrap();
let mut redis = bb8::Pool::builder().build(manager).await.unwrap();

// Sidekiq server
let mut p = Processor::new(
    redis,
    logger.clone(),
    vec!["yolo".to_string(), "brolo".to_string()],
);

// Add known workers
p.register(PaymentReportWorker::new(logger.clone()));

// Custom Middlewares
p.using(FilterExpiredUsersMiddleware::new(logger.clone()))
    .await;

// Start the server
p.run().await;

Periodic Jobs

Periodic cron jobs are supported out of the box. All you need to specify is a valid cron string and a worker instance. You can optionally supply arguments, a queue, a retry flag, and a name that will be logged when a worker is submitted.

Example:

// Clear out all periodic jobs and their schedules
periodic::destroy_all(redis).await?;

// Add a new periodic job
periodic::builder("0 0 8 * * *")?
    .name("Email clients with an oustanding balance daily at 8am UTC")
    .queue("reminders")
    .args(EmailReminderArgs {
        report_type: "outstanding_balance",
    })?
    .register(&mut p, EmailReminderWorker)
    .await?;

Periodic jobs are not removed automatically. If your project adds a periodic job and then later removes the periodic::builder call, the periodic job will still exist in redis. You can call periodic::destroy_all(redis).await? at the start of your program to ensure only the periodic jobs added by the latest version of your program will be executed.

The implementation relies on a sorted set in redis. It stores a json payload of the periodic job with a score equal to the next scheduled UTC time of the cron string. All processes will periodically poll for changes and atomically update the score to the new next scheduled UTC time for the cron string. The worker that successfully changes the score atomically will enqueue a new job. Processes that don't successfully update the score will move on. This implementation detail means periodic jobs never leave redis. Another detail is that json when decoded and then encoded might not produce the same value as the original string. Ex: {"a":"b","c":"d"} might become {"c":"d","a":b"}. To keep the json representation consistent, when updating a periodic job with its new score in redis, the original json string will be used again to keep things consistent.

Server Middleware

One great feature of sidekiq is its middleware pattern. This library reimplements the sidekiq server middleware pattern in rust. In the example below supposes you have an app that performs work only for paying customers. The middleware below will hault jobs from being executed if the customers have expired. One thing kind of interesting about the implementation is that we can rely on serde to conditionally type-check workers. For example, suppose I only care about user-centric workers, and I identify those by their user_guid as a parameter. With serde it's easy to validate your paramters.

struct FilterExpiredUsersMiddleware {
    logger: slog::Logger,
}

impl FilterExpiredUsersMiddleware {
    fn new(logger: slog::Logger) -> Self {
        Self { logger }
    }
}

#[derive(Deserialize)]
struct FiltereExpiredUsersArgs {
    user_guid: String,
}

impl FiltereExpiredUsersArgs {
    fn is_expired(&self) -> bool {
        self.user_guid == "USR-123-EXPIRED"
    }
}

#[async_trait]
impl ServerMiddleware for FilterExpiredUsersMiddleware {
    async fn call(
        &self,
        chain: ChainIter,
        job: &Job,
        worker: Arc<WorkerRef>,
        redis: RedisPool,
    ) -> ServerResult {
        // Use serde to check if a user_guid is part of the job args.
        let args: Result<(FiltereExpiredUsersArgs,), serde_json::Error> =
            serde_json::from_value(job.args.clone());

        // If we can safely deserialize then attempt to filter based on user guid.
        if let Ok((filter,)) = args {
            if filter.is_expired() {
                error!(
                    self.logger,
                    "Detected an expired user, skipping this job";
                    "class" => job.class,
                    "jid" => job.jid,
                    "user_guid" => filter.user_guid,
                );
                return Ok(());
            }
        }

        // This customer is not expired, so we may continue.
        chain.next(job, worker, redis).await
    }
}

Customization Details

Namespacing the workers

It's still very common to use the redis-namespace gem with ruby sidekiq workers. This library supports namespacing redis commands by using a connection customizer when you build the connection pool.

let manager = sidekiq::RedisConnectionManager::new("redis://127.0.0.1/")?;
let redis = bb8::Pool::builder()
    .connection_customizer(sidekiq::with_custom_namespace("my_cool_app".to_string()))
    .build(manager)
    .await?;

Now all commands used by this library will be prefixed with my_cool_app:, example: ZDEL my_cool_app:scheduled {...}.

Passing database connections into the workers

Workers will often need access to other software components like database connections, http clients, etc. You can define these on your worker struct so long as they implement Clone. Example:

#[derive(Clone)]
struct ExampleWorker {
    redis: RedisPool,
}


#[async_trait]
impl Worker<()> for ExampleWorker {
    async fn perform(&self, args: PaymentReportArgs) -> Result<(), Box<dyn std::error::Error>> {
        use redis::AsyncCommands;

        // And then they are available here...
        let times_called: usize = self
            .redis
            .get()
            .await?
            .unnamespaced_borrow_mut()
            .incr("example_of_accessing_the_raw_redis_connection", 1)
            .await?;

        debug!(self.logger, "Called this worker"; "times_called" => times_called);
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// ...
    let mut p = Processor::new(
        redis.clone(),
        logger.clone(),
        vec!["low_priority".to_string()],
    );

    p.register(ExampleWorker{ redis: redis.clone() });
}

Customizing the worker name for workers under a nested ruby module

You mind find that your worker under a module does not match with a ruby worker under a module. A nested rusty-sidekiq worker workers::MyWorker will only keep the final type name MyWorker when registering the worker for some "class name". Meaning, if a ruby worker is enqueued with the class Workers::MyWorker, the workers::MyWorker type will not process that work. This is because by default the class name is generated at compile time based on the worker struct name. To override this, redefine one of the default trait methods:

pub struct MyWorker;

#[async_trait]
impl Worker<()> for MyWorker {
    async fn perform(&self, _args: ()) -> ServerResult {
        Ok(())
    }

    fn class_name() -> String
    where
        Self: Sized,
    {
        "Workers::MyWorker".to_string()
    }
}

And now when ruby enqueues a Workers::MyWorker job, it will be picked up by rust-sidekiq.

License

MIT