qrush 2.0.1

Lightweight Job Queue and Task Scheduler for Rust (Actix + Redis + Cron)
Documentation
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# Qrush

[![Crates.io](https://img.shields.io/crates/v/qrush)](https://crates.io/crates/qrush)
[![Documentation](https://docs.rs/qrush/badge.svg)](https://docs.rs/qrush)
[![License](https://img.shields.io/crates/l/qrush)](LICENSE)
[![Downloads](https://img.shields.io/crates/d/qrush)](https://crates.io/crates/qrush)

![QRush](https://srotasspace.s3.ap-south-1.amazonaws.com/srotas.svg)

A lightweight, production-ready job queue and task scheduler for Rust applications built on Redis and Tokio. The core is web-framework agnostic, and the optional built-in dashboard works with **either Actix Web or Axum**. Qrush provides both integrated and separate process modes, making it suitable for everything from simple background tasks to large-scale distributed systems.

## Features

- πŸš€ **Dual Deployment Modes**: Integrated (single process) or separate worker process
- 🧩 **Framework Choice**: Optional dashboard for Actix Web *or* Axum; the queue/worker core needs neither
- ⚑ **High Performance**: Built on Redis and Tokio for maximum throughput
- πŸ“… **Cron Scheduling**: Full cron expression support for recurring tasks
- ⏱️ **Delayed Jobs**: Schedule jobs to run after a specified delay
- πŸ“Š **Built-in Metrics UI**: Real-time dashboard for monitoring queues, jobs, and workers
- πŸ”’ **Security**: Optional Basic Auth for metrics endpoints
- 🎯 **Type-Safe**: Leverages Rust's type system for safe job handling
- πŸ”„ **Graceful Shutdown**: Clean worker shutdown with configurable grace periods
- πŸ“ˆ **Scalable**: Support for multiple queues with different priorities and concurrency levels

## Feature Flags

The built-in dashboard is optional and works with **either Actix or Axum** β€”
pick the one that matches your app.

| Feature | Default | Description |
|---------|---------|-------------|
| `dashboard-actix` | ❌ | Metrics dashboard served with Actix Web (`qrush::routes::metrics_route`). Pulls in Actix Web, Tera, and the web stack. |
| `dashboard-axum` | ❌ | Metrics dashboard served with Axum (`qrush::routes::axum_route`). Pulls in Axum, Tera, and the web stack. |
| `dashboard` | ❌ | Back-compat alias for `dashboard-actix`. |

**Library-only usage (default).** No dashboard framework is enabled by default,
so a plain dependency gives you `enqueue` + workers with no web stack:

```toml
[dependencies]
qrush = "2.0.0"
```

To mount the dashboard, opt into one framework:

```toml
# Actix
qrush = { version = "2.0.0", features = ["dashboard-actix"] }

# Axum
qrush = { version = "2.0.0", features = ["dashboard-axum"] }
```

### Migrating from 1.x to 2.0

In 1.x the dashboard was Actix-only and enabled by default. In 2.0 it is
framework-selectable and **off by default**. Nothing else changed β€” the
route-wiring function and all queue/worker/cron APIs are the same.

| | 1.x | 2.0 |
|---|---|---|
| Dashboard default | on (Actix) | off |
| Enable Actix dashboard | (default) | `features = ["dashboard-actix"]` |
| Enable Axum dashboard | not available | `features = ["dashboard-axum"]` |

```toml
# 1.x
qrush = "1.0.1"

# 2.0 β€” Actix (equivalent to the old default; no code changes needed)
qrush = { version = "2.0.0", features = ["dashboard-actix"] }
```

If you only used `enqueue` + workers (no dashboard), a plain `qrush = "2.0.0"`
now pulls in **less** β€” the web stack is no longer compiled by default. See the
[CHANGELOG](CHANGELOG.md) for the full list of changes.

## Quick Start

### Installation

Add to your `Cargo.toml`:

```toml
[dependencies]
qrush = "2.0.0"
tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
serde = { version = "1", features = ["derive"] }
async-trait = "0.1"
anyhow = "1"
futures = "0.3"
```

> `qrush` bundles its own Redis client (with cluster support), so you don't need
> to depend on `redis` directly unless you use it yourself.

### Basic Usage (Integrated Mode)

```rust
use qrush::job::Job;
use qrush::queue::{enqueue, enqueue_in};
use qrush::config::QueueConfig;
use qrush::registry::register_job;
use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use futures::future::BoxFuture;
use anyhow::Result;

#[derive(Clone, Serialize, Deserialize)]
pub struct EmailJob {
    pub to: String,
    pub subject: String,
}

#[async_trait]
impl Job for EmailJob {
    async fn perform(&self) -> Result<()> {
        println!("Sending email to {}: {}", self.to, self.subject);
        // Your email sending logic here
        Ok(())
    }

    fn name(&self) -> &'static str { "EmailJob" }
    fn queue(&self) -> &'static str { "default" }
}

impl EmailJob {
    pub fn name() -> &'static str { "EmailJob" }
    pub fn handler(payload: String) -> BoxFuture<'static, Result<Box<dyn Job>>> {
        Box::pin(async move {
            let job: EmailJob = serde_json::from_str(&payload)?;
            Ok(Box::new(job) as Box<dyn Job>)
        })
    }
}

#[tokio::main]
async fn main() -> Result<()> {
    // Set Redis URL
    std::env::set_var("REDIS_URL", "redis://127.0.0.1:6379");
    
    // Register job
    register_job(EmailJob::name(), EmailJob::handler);
    
    // Initialize queues
    let queues = vec![
        QueueConfig::new("default", 5, 0),
    ];
    QueueConfig::initialize(
        "redis://127.0.0.1:6379".to_string(),
        queues
    ).await?;
    
    // Enqueue a job
    enqueue(EmailJob {
        to: "user@example.com".to_string(),
        subject: "Hello!".to_string(),
    }).await?;
    
    // Keep running
    tokio::signal::ctrl_c().await?;
    Ok(())
}
```

## Architecture

QRush supports two deployment modes:

### Integrated Mode

Workers run in the same process as your application. Perfect for small to medium applications.

```
β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚   Application        β”‚
β”‚   (Single Process)   β”‚
β”‚                      β”‚
β”‚  β€’ HTTP Server       β”‚
β”‚  β€’ Enqueue Jobs      β”‚
β”‚  β€’ Process Jobs      β”‚ ← Workers here
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜
```

### Separate Process Mode

Workers run in a dedicated process. Recommended for production environments.

```
β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”         β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚   Web Server         β”‚         β”‚  qrush-engine       β”‚
β”‚   (cargo run)        β”‚         β”‚  (separate process) β”‚
β”‚                      β”‚         β”‚                     β”‚
β”‚  β€’ HTTP Server       β”‚         β”‚  β€’ Worker Pools     β”‚
β”‚  β€’ Enqueue Jobs ─────┼──Redis──┼─▢ Process Jobs      β”‚
β”‚  β€’ Serve Routes      β”‚         β”‚  β€’ Cron Scheduler   β”‚
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜         β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜
```

## Documentation

### Integrated Mode

See [Part 1: Integrated Mode](#integrated-mode-detailed) below for complete setup instructions.

### Separate Process Mode

See [Part 2: Separate Process Mode](#separate-process-mode-detailed) below for production deployment.

## API Reference

### Core Traits

- `Job`: Implement this trait for your job types
- `CronJob`: Implement for recurring scheduled jobs

### Core Functions

- `enqueue(job) -> QrushResult<String>`: Enqueue a job immediately; returns the job ID
- `enqueue_in(job, delay_secs) -> QrushResult<String>`: Enqueue a job with a delay; returns the job ID
- `register_job(name, handler)`: Register a job handler
- `QueueConfig::initialize(redis_url, queues)`: Start worker pools **and** the cron scheduler

### Cron Scheduling

All under `qrush::cron::cron_scheduler::CronScheduler` (see [Cron Jobs](#cron-jobs)):

- `register_cron_job(job) -> Result<()>`: Persist a schedule to Redis
- `list_cron_jobs() -> Result<Vec<CronJobMeta>>`: List registered cron jobs
- `run_now(cron_id) -> Result<String>`: Enqueue a cron job immediately
- `toggle_cron_job(cron_id, enabled) -> Result<()>`: Pause / resume a schedule
- `delete_cron_job(cron_id) -> Result<()>`: Remove a schedule

### Errors

The public API returns `QrushResult<T>` (`Result<T, QrushError>`). `QrushError`
distinguishes `Redis`, `Serialization`, and `Config` failures, and implements
`std::error::Error`, so it still propagates through `?` in `anyhow`-based code.

### Engine Runtime

- `qrush::engine::run_engine(redis_url, queues, shutdown_grace_secs)`: Run worker process
- `qrush::engine::parse_queues(spec)`: Parse queue specification string

### Command-Line Interface

The crate also ships reference binaries β€” `qrush` (a management CLI with
`start`/`stop`/`status`/`stats`/`queues`/`jobs` subcommands) and `qrush-engine`
(the worker process) β€” that you can adapt for your own app. See
[`src/bin/cli.md`](src/bin/cli.md) for the full CLI guide.

## Examples

### Runnable dashboard examples

The repo ships a complete, runnable dashboard example for each framework. With a
Redis instance available (`REDIS_URL`, defaults to `redis://127.0.0.1:6379`):

```sh
# Actix β€” serves http://127.0.0.1:8080/qrush/metrics
cargo run --example actix_dashboard --features dashboard-actix

# Axum β€” serves http://127.0.0.1:8080/qrush/metrics
cargo run --example axum_dashboard --features dashboard-axum
```

### Cron Jobs

A cron job is a regular [`Job`](#basic-usage-integrated-mode) that runs on a schedule instead of
being enqueued by hand. The work still lives in `Job::perform`; `CronJob` only
adds *when* to run it. Follow these three steps.

#### Step 1 β€” Define the job and its `perform()`

This is identical to any other QRush job: implement `Job` (the work + a handler
so a worker can rebuild it from Redis).

```rust
use qrush::job::Job;
use qrush::registry::register_job;
use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use futures::future::BoxFuture;
use anyhow::Result;

#[derive(Clone, Serialize, Deserialize)]
pub struct EmailJob {
    pub to: String,
    pub subject: String,
}

#[async_trait]
impl Job for EmailJob {
    // πŸ‘‡ This is the execution β€” it runs every time the schedule fires.
    async fn perform(&self) -> Result<()> {
        println!("Sending email to {}: {}", self.to, self.subject);
        // Your recurring work goes here.
        Ok(())
    }

    fn name(&self) -> &'static str { "EmailJob" }
    fn queue(&self) -> &'static str { "default" }
}

impl EmailJob {
    pub fn name() -> &'static str { "EmailJob" }

    // Lets a worker rebuild the job from its stored payload.
    pub fn handler(payload: String) -> BoxFuture<'static, Result<Box<dyn Job>>> {
        Box::pin(async move {
            let job: EmailJob = serde_json::from_str(&payload)?;
            Ok(Box::new(job) as Box<dyn Job>)
        })
    }
}
```

#### Step 2 β€” Add the schedule (`CronJob`)

Attach a cron expression and a unique id to the same type.

```rust
use qrush::cron::cron_job::CronJob;

#[async_trait]
impl CronJob for EmailJob {
    // 6-field: sec min hour day month weekday. See "Cron Expressions" below.
    fn cron_expression(&self) -> &'static str { "0 0 * * * *" } // every hour
    fn cron_id(&self) -> &'static str { "hourly_email" }        // must be unique
}
```

#### Step 3 β€” Register and start it in `main`

The job above is framework-agnostic; only `main` differs. In **both** frameworks
the order is the same:

1. `set_redis_url(...)` β€” required before any Redis call.
2. `register_job(...)` β€” so a worker can run the job.
3. `CronScheduler::register_cron_job(...)` β€” saves the schedule to Redis.
4. `QueueConfig::initialize(...)` β€” starts the workers **and** the cron scheduler.

> ⚠️ The cron scheduler only runs where `QueueConfig::initialize` is called. In
> [Separate Process Mode]#separate-process-mode-detailed that's the engine
> binary, not the web server β€” put steps 2–4 there.

**Actix** (`features = ["dashboard-actix"]`):

```rust
use qrush::config::{set_redis_url, QueueConfig};
use qrush::registry::register_job;
use qrush::cron::cron_scheduler::CronScheduler;
use qrush::routes::metrics_route::qrush_metrics_routes;
use actix_web::{web, App, HttpServer};

#[actix_web::main]
async fn main() -> anyhow::Result<()> {
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url.clone())?;                       // 1

    register_job(EmailJob::name(), EmailJob::handler);       // 2

    let job = EmailJob {                                     // 3
        to: "user@example.com".into(),
        subject: "Hourly report".into(),
    };
    CronScheduler::register_cron_job(job).await?;

    let queues = vec![QueueConfig::new("default", 5, 0)];    // 4
    QueueConfig::initialize(redis_url, queues).await?;

    // Serve the dashboard at http://127.0.0.1:8080/qrush/metrics
    HttpServer::new(|| {
        App::new().service(web::scope("/qrush").configure(qrush_metrics_routes))
    })
    .bind("0.0.0.0:8080")?
    .run()
    .await?;
    Ok(())
}
```

**Axum** (`features = ["dashboard-axum"]`):

```rust
use qrush::config::{set_redis_url, QueueConfig};
use qrush::registry::register_job;
use qrush::cron::cron_scheduler::CronScheduler;
use qrush::routes::axum_route::qrush_metrics_router;
use axum::Router;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url.clone())?;                       // 1

    register_job(EmailJob::name(), EmailJob::handler);       // 2

    let job = EmailJob {                                     // 3
        to: "user@example.com".into(),
        subject: "Hourly report".into(),
    };
    CronScheduler::register_cron_job(job).await?;

    let queues = vec![QueueConfig::new("default", 5, 0)];    // 4
    QueueConfig::initialize(redis_url, queues).await?;

    // Serve the dashboard at http://127.0.0.1:8080/qrush/metrics
    let app = Router::new().nest("/qrush", qrush_metrics_router());
    let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await?;
    axum::serve(listener, app).await?;
    Ok(())
}
```

**That's it.** When the schedule fires, QRush enqueues the job onto its `queue()`
and a worker runs `perform()`. Watch it (and manage schedules) on the dashboard
at `/qrush/metrics/extras/cron`.

> **On restart:** `register_cron_job` errors if a job with the same `cron_id`
> already exists in Redis, so the `?` above would abort a second boot. The
> schedule already survives restarts, so either skip re-registering, treat the
> duplicate as non-fatal (log and continue instead of `?`), or call
> `CronScheduler::delete_cron_job("hourly_email")` first to re-seed it.

#### Managing cron jobs

Manage schedules from the dashboard at `/qrush/metrics/extras/cron`, or
programmatically via `CronScheduler`:

```rust
use qrush::cron::cron_scheduler::CronScheduler;

CronScheduler::list_cron_jobs().await?;              // -> Vec<CronJobMeta>
CronScheduler::run_now("hourly_email").await?;       // enqueue once, right now
CronScheduler::toggle_cron_job("hourly_email", false).await?; // pause
CronScheduler::toggle_cron_job("hourly_email", true).await?;  // resume
CronScheduler::delete_cron_job("hourly_email").await?;        // remove entirely
```

To register a job that starts **paused**, override `enabled()` on the `CronJob`
impl (it defaults to `true`); enable it later from the dashboard or with
`toggle_cron_job`:

```rust
fn enabled(&self) -> bool { false }
```

A disabled job stays registered but is skipped and removed from the run schedule
until re-enabled.

### Multiple Queues

```rust
let queues = vec![
    QueueConfig::new("default", 5, 0),      // 5 workers, priority 0
    QueueConfig::new("critical", 10, 0),   // 10 workers, priority 0
    QueueConfig::new("low", 2, 1),         // 2 workers, priority 1
];
```

### Metrics UI

> Requires a dashboard feature β€” `dashboard-actix` or `dashboard-axum` (not
> enabled by default). See [Feature Flags]#feature-flags.

Access the built-in metrics dashboard at `/qrush/metrics`:

- Queue statistics and job counts
- Worker status and health
- Cron job management
- Job retry and deletion
- CSV export

## Requirements

- Rust 1.89.0 or later
- Redis 6.0 or later
- Tokio runtime (multi-threaded)

## Environment Variables

```bash
# Required
REDIS_URL=redis://127.0.0.1:6379

# Optional
QRUSH_BASIC_AUTH=admin:password  # Basic auth for metrics
RUST_LOG=info,qrush=info         # Logging level
```


# Detailed Documentation

## Integrated Mode (Detailed)

**Use this mode when:** You want a simple setup with workers running in the same process as your web server.

### 1. Add Dependencies

```toml
[dependencies]
# Pick the dashboard framework you use: "dashboard-actix" or "dashboard-axum"
qrush = { version = "2.0.0", features = ["dashboard-actix"] }
actix-web = "4"   # or: axum = "0.8"
tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
serde = { version = "1", features = ["derive"] }
async-trait = "0.1"
anyhow = "1"
futures = "0.3"
```

### 2. Define a Job

```rust
use qrush::job::Job;
use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use futures::future::BoxFuture;
use anyhow::Result;

#[derive(Clone, Serialize, Deserialize)]
pub struct NotifyUser {
    pub user_id: String,
    pub message: String,
}

#[async_trait]
impl Job for NotifyUser {
    async fn perform(&self) -> Result<()> {
        println!("Notify {} -> {}", self.user_id, self.message);
        Ok(())
    }

    fn name(&self) -> &'static str { "NotifyUser" }
    fn queue(&self) -> &'static str { "default" }
}

impl NotifyUser {
    pub fn name() -> &'static str { "NotifyUser" }
    pub fn handler(payload: String) -> BoxFuture<'static, Result<Box<dyn Job>>> {
        Box::pin(async move {
            let job: NotifyUser = serde_json::from_str(&payload)?;
            Ok(Box::new(job) as Box<dyn Job>)
        })
    }
}
```

### 3. Initialize QRush

The queue/worker setup is identical for both frameworks β€” only the dashboard
wiring differs. The dashboard mounts at `/qrush/metrics/...` in both cases.

**Actix** (`features = ["dashboard-actix"]`):

```rust
use qrush::config::{QueueConfig, set_redis_url};
use qrush::registry::register_job;
use qrush::routes::metrics_route::qrush_metrics_routes;
use actix_web::{web, App, HttpServer};

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    // Set Redis URL
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url.clone())?;

    // Register jobs
    register_job(NotifyUser::name(), NotifyUser::handler);

    // Initialize queues
    let queues = vec![
        QueueConfig::new("default", 5, 0),
    ];
    QueueConfig::initialize(redis_url, queues).await?;

    // Start web server
    HttpServer::new(|| {
        App::new()
            .service(web::scope("/qrush").configure(qrush_metrics_routes))
    })
    .bind("0.0.0.0:8080")?
    .run()
    .await
}
```

**Axum** (`features = ["dashboard-axum"]`):

```rust
use qrush::config::{QueueConfig, set_redis_url};
use qrush::registry::register_job;
use qrush::routes::axum_route::qrush_metrics_router;
use axum::Router;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    // Set Redis URL
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url.clone())?;

    // Register jobs
    register_job(NotifyUser::name(), NotifyUser::handler);

    // Initialize queues
    let queues = vec![
        QueueConfig::new("default", 5, 0),
    ];
    QueueConfig::initialize(redis_url, queues).await?;

    // Mount the dashboard under /qrush
    let app = Router::new().nest("/qrush", qrush_metrics_router());

    let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await?;
    axum::serve(listener, app).await?;
    Ok(())
}
```

### 4. Enqueue Jobs

```rust
use qrush::queue::{enqueue, enqueue_in};

// Immediate
enqueue(NotifyUser {
    user_id: "123".to_string(),
    message: "Hello".to_string(),
}).await?;

// Delayed (300 seconds)
enqueue_in(NotifyUser {
    user_id: "123".to_string(),
    message: "Reminder".to_string(),
}, 300).await?;
```

---

## Separate Process Mode (Detailed)

**Use this mode when:** You want production-ready separation with workers in a dedicated process.

### 1. Create Engine Binary

Create `src/bin/qrush_engine.rs`:

```rust
use qrush::engine::{run_engine, parse_queues};
use qrush::config::set_redis_url;
use qrush::registry::register_job;
use qrush::cron::cron_scheduler::CronScheduler;

// Your job types
use your_app::jobs::NotifyUser;

#[tokio::main(flavor = "multi_thread")]
async fn main() -> anyhow::Result<()> {
    dotenvy::dotenv().ok();
    
    // Setup logging
    tracing_subscriber::fmt::init();
    
    // Get Redis URL
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    
    // Set Redis URL (needed before registering cron jobs)
    set_redis_url(redis_url.clone())?;
    
    // Register jobs
    register_job(NotifyUser::name(), NotifyUser::handler);
    
    // Register cron jobs (optional)
    let daily_report = DailyReportJob { /* ... */ };
    CronScheduler::register_cron_job(daily_report).await?;
    
    // Parse queues: "name:concurrency:priority"
    let queues = parse_queues("default:5:0,critical:10:0");
    
    // Run engine
    run_engine(redis_url, queues, 5).await
}
```

### 2. Update Cargo.toml

The engine binary above uses `tracing_subscriber` for logging and `dotenvy`
to load `.env`, so add them alongside the `[[bin]]` entry:

```toml
[dependencies]
tracing-subscriber = { version = "0.3", features = ["env-filter"] }
dotenvy = "0.15"

[[bin]]
name = "qrush_engine"
path = "src/bin/qrush_engine.rs"
```

### 3. Web Server (No Workers)

In your web server `main.rs`, only register jobs for enqueueing β€” do **not**
call `QueueConfig::initialize` (that starts workers; the engine process owns
them here). Use whichever framework you enabled. To also expose the dashboard,
mount it exactly as shown in [Integrated Mode β†’ Initialize QRush](#3-initialize-qrush).

**Actix** (`features = ["dashboard-actix"]`):

```rust
use qrush::config::set_redis_url;
use qrush::registry::register_job;
use qrush::routes::metrics_route::qrush_metrics_routes;
use actix_web::{web, App, HttpServer};

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url).expect("failed to set Redis URL");

    // Register jobs (for serialization only β€” no worker initialization).
    register_job(NotifyUser::name(), NotifyUser::handler);

    HttpServer::new(|| {
        App::new().service(web::scope("/qrush").configure(qrush_metrics_routes))
    })
    .bind("0.0.0.0:8080")?
    .run()
    .await
}
```

**Axum** (`features = ["dashboard-axum"]`):

```rust
use qrush::config::set_redis_url;
use qrush::registry::register_job;
use qrush::routes::axum_route::qrush_metrics_router;
use axum::Router;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let redis_url = std::env::var("REDIS_URL")
        .unwrap_or_else(|_| "redis://127.0.0.1:6379".to_string());
    set_redis_url(redis_url)?;

    // Register jobs (for serialization only β€” no worker initialization).
    register_job(NotifyUser::name(), NotifyUser::handler);

    let app = Router::new().nest("/qrush", qrush_metrics_router());
    let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await?;
    axum::serve(listener, app).await?;
    Ok(())
}
```

### 4. Run Both Processes

**Terminal 1 - Web Server:**
```bash
export REDIS_URL=redis://127.0.0.1:6379
cargo run
```

**Terminal 2 - Worker Engine:**
```bash
export REDIS_URL=redis://127.0.0.1:6379
cargo run --bin qrush_engine
```

---

## Cron Expressions

QRush accepts both **6-field** (`sec min hour day month weekday`) and **5-field**
(`min hour day month weekday`) expressions. A 5-field expression defaults seconds
to `0`, so `*/5 * * * *` and `0 */5 * * * *` are equivalent.

Common examples:

| Expression          | Meaning                          |
| ------------------- | -------------------------------- |
| `"* * * * *"`       | Every minute (5-field)           |
| `"0 * * * * *"`     | Every minute (6-field)           |
| `"0 */5 * * * *"`   | Every 5 minutes                  |
| `"0 0 * * * *"`     | Every hour                       |
| `"0 0 0 * * *"`     | Daily at midnight                |
| `"0 30 9 * * *"`    | Daily at 09:30                   |
| `"0 0 0 * * 1"`     | Every Monday at midnight         |
| `"0 0 9 * * MON-FRI"` | Weekdays at 09:00              |
| `"0 0 0 1 * *"`     | First day of every month         |
| `"0 0 12 1 JAN *"`  | Jan 1st at noon                  |

Each field supports the usual operators:

- `*` β€” any value
- `a` β€” an exact value
- `a,b,c` β€” a list
- `a-b` β€” an inclusive range
- `*/n` β€” a step over the whole range (e.g. `*/15` in minutes)
- `a-b/n` β€” a step within a range
- **Names**: months `JAN`–`DEC`, weekdays `SUN`–`SAT` (case-insensitive).
  For the weekday field, both `0` and `7` mean Sunday.

**Timezone.** Expressions evaluate in UTC by default. Override per job with
`fn timezone(&self) -> &'static str` on the `CronJob` impl, returning any IANA
name (e.g. `"Asia/Kolkata"`, `"America/New_York"`) β€” so `"0 0 9 * * *"` fires at
09:00 in that zone, DST included.

```rust
#[async_trait]
impl CronJob for EmailJob {
    fn cron_expression(&self) -> &'static str { "0 0 9 * * *" } // 9 AM…
    fn cron_id(&self) -> &'static str { "morning_email" }
    fn timezone(&self) -> &'static str { "Asia/Kolkata" }       // …IST
}
```

**Precision & missed runs.** The scheduler ticks every ~5 seconds, so a job fires
within a few seconds of its scheduled time (don't rely on sub-5s precision). If
the scheduler was down when a run was due, that run fires once on the next tick
and is then re-anchored to its next future slot β€” missed cycles are **not**
backfilled one-per-cycle. Claiming is atomic in Redis, so running multiple engine
processes will **not** double-fire the same job.

## Metrics Endpoints

- `GET /qrush/metrics` - Dashboard overview
- `GET /qrush/metrics/queues/{queue}` - Queue details
- `GET /qrush/metrics/extras/cron` - Cron job management
- `GET /qrush/metrics/extras/workers` - Worker status
- `GET /qrush/metrics/health` - Health check
- `POST /qrush/metrics/jobs/action` - Job actions (retry/delete)

## Production Tips

- Use separate process mode for production
- Set `QRUSH_BASIC_AUTH` to protect metrics endpoints
- Configure appropriate queue concurrency based on your workload
- Monitor Redis memory usage
- Use graceful shutdown for zero-downtime deployments
- Scale workers horizontally by running multiple engine processes



## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

## Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

## Support

- **Documentation**: [docs.rs/qrush]https://docs.rs/qrush
- **Issues**: [GitHub Issues]https://github.com/srotas-space/qrush/issues
- **Discussions**: [GitHub Discussions]https://github.com/srotas-space/qrush/discussions

---

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