celers-backend-db

Version: 0.2.0 | Status: [Alpha] | Updated: 2026-03-27

Database (PostgreSQL/MySQL) result backend for CeleRS. Provides persistent task result storage, event persistence, chord state management, and optional distributed locks using SQL databases.

Features

• PostgreSQL and MySQL support via SQLx
• Task result storage with configurable TTL
• Chord barrier synchronization (atomic counters)
• Event persistence for task lifecycle tracking
• Distributed locks (optional, feature-gated)
• SQL-based result queries and analytics

Usage

Add to your Cargo.toml:

[dependencies]
celers-backend-db = { version = "0.2", features = ["postgres"] }

PostgreSQL Backend

use celers_backend_db::PostgresResultBackend;
use celers_backend_redis::ResultBackend;
use uuid::Uuid;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut backend = PostgresResultBackend::new("postgres://localhost/celers").await?;
    backend.migrate().await?;

    let task_id = Uuid::new_v4();
    let meta = TaskMeta::new(task_id, "my_task".to_string());
    backend.store_result(task_id, &meta).await?;

    if let Some(result) = backend.get_result(task_id).await? {
        println!("Task result: {:?}", result.result);
    }

    Ok(())
}

Event Persistence

use celers_backend_db::{DbEventPersister, DbEventPersisterConfig};

let config = DbEventPersisterConfig::default();
let persister = DbEventPersister::new(pool, config);

Feature Flags

Part of CeleRS

This crate is part of the CeleRS project, a Celery-compatible distributed task queue for Rust.

Testing

7 tests passing (unit tests; integration tests require PostgreSQL/MySQL)

License

Apache-2.0

Copyright (c) COOLJAPAN OU (Team Kitasan)