Expand description
§apalis-sqlite
Background task processing for Rust using apalis and sqlite.
§Features
- Reliable job queue using SQLite as the backend.
- Multiple storage types: standard polling and event-driven (hooked) storage.
- Custom codecs for serializing/deserializing job arguments as bytes.
- Heartbeat and orphaned job re-enqueueing for robust job processing.
- Integration with
apalisworkers and middleware.
§Storage Types
SqliteStorage: Standard polling-based storage.SqliteStorageWithHook: Event-driven storage using SQLite update hooks for low-latency job fetching.SharedSqliteStorage: Shared storage for multiple job types.
The naming is designed to clearly indicate the storage mechanism and its capabilities, but under the hood the result is the SqliteStorage struct with different configurations.
§Examples
§Basic Worker Example
use std::time::Duration;
use apalis::prelude::*;
use apalis_sqlite::*;
use futures::stream::{self, StreamExt};
#[tokio::main]
async fn main() {
let pool = SqlitePool::connect(":memory:").await.unwrap();
SqliteStorage::setup(&pool).await.unwrap();
let mut backend = SqliteStorage::new(&pool);
let mut start = 0;
let mut items = stream::repeat_with(move || {
start += 1;
let task = Task::builder(start)
.run_after(Duration::from_secs(1))
.with_ctx(SqlContext::new().with_priority(1))
.build();
task
})
.take(10);
backend.push_all(&mut items).await.unwrap();
async fn send_reminder(item: usize, wrk: WorkerContext) -> Result<(), BoxDynError> {
Ok(())
}
let worker = WorkerBuilder::new("worker-1")
.backend(backend)
.build(send_reminder);
worker.run().await.unwrap();
}§Hooked Worker Example (Event-driven)
use std::time::Duration;
use apalis::prelude::*;
use apalis_sqlite::*;
use futures::stream::{self, StreamExt};
#[tokio::main]
async fn main() {
let lazy_strategy = StrategyBuilder::new()
.apply(IntervalStrategy::new(Duration::from_secs(5)))
.build();
let config = Config::new("queue")
.with_poll_interval(lazy_strategy)
.set_buffer_size(5);
let backend = SqliteStorage::new_with_callback(":memory:", &config);
let pool = backend.pool();
SqliteStorage::setup(&pool).await.unwrap();
tokio::spawn({
let pool = pool.clone();
let config = config.clone();
async move {
tokio::time::sleep(Duration::from_secs(2)).await;
let mut start = 0;
let items = stream::repeat_with(move || {
start += 1;
Task::builder(serde_json::to_vec(&start).unwrap())
.run_after(Duration::from_secs(1))
.with_ctx(SqlContext::new().with_priority(start))
.build()
})
.take(20)
.collect::<Vec<_>>()
.await;
apalis_sqlite::sink::push_tasks(pool, config, items).await.unwrap();
}
});
async fn send_reminder(item: usize, wrk: WorkerContext) -> Result<(), BoxDynError> {
Ok(())
}
let worker = WorkerBuilder::new("worker-2")
.backend(backend)
.build(send_reminder);
worker.run().await.unwrap();
}§Workflow Example
use std::time::Duration;
use apalis::prelude::*;
use apalis_sqlite::*;
use apalis_workflow::*;
#[tokio::main]
async fn main() {
let workflow = Workflow::new("odd-numbers-workflow")
.and_then(|a: usize| async move {
Ok::<Vec<usize>, BoxDynError>((0..=a).collect::<Vec<usize>>())
})
.filter_map(|x: usize| async move {
if x % 2 != 0 { Some(x) } else { None }
})
.filter_map(|x: usize| async move {
if x % 3 != 0 { Some(x) } else { None }
})
.filter_map(|x: usize| async move {
if x % 5 != 0 { Some(x) } else { None }
})
.delay_for(Duration::from_millis(1000))
.and_then(|a: Vec<usize>| async move {
println!("Sum: {}", a.iter().sum::<usize>());
Ok::<(), BoxDynError>(())
});
let pool = SqlitePool::connect(":memory:").await.unwrap();
SqliteStorage::setup(&pool).await.unwrap();
let mut sqlite = SqliteStorage::new_in_queue(&pool, "test-workflow");
sqlite.push_start(100usize).await.unwrap();
let worker = WorkerBuilder::new("rango-tango")
.backend(sqlite)
.on_event(|ctx, ev| {
println!("On Event = {:?}", ev);
if matches!(ev, Event::Error(_)) {
ctx.stop().unwrap();
}
})
.build(workflow);
worker.run().await.unwrap();
}§Shared Example
Full support for sharing the same connection. This example shows how to run multiple types with one function
use std::{collections::HashMap, time::Duration};
use apalis::prelude::*;
use apalis_sqlite::{SharedSqliteStorage, SqliteStorage};
use futures::stream;
#[tokio::main]
async fn main() {
let mut store = SharedSqliteStorage::new(":memory:");
SqliteStorage::setup(store.pool()).await.unwrap();
let mut map_store = store.make_shared().unwrap();
let mut int_store = store.make_shared().unwrap();
map_store
.push_stream(&mut stream::iter(vec![HashMap::<String, String>::new()]))
.await
.unwrap();
int_store.push(99).await.unwrap();
async fn send_reminder<T, I>(
_: T,
_task_id: TaskId<I>,
wrk: WorkerContext,
) -> Result<(), BoxDynError> {
tokio::time::sleep(Duration::from_secs(2)).await;
wrk.stop().unwrap();
println!("Reminder sent!");
Ok(())
}
let int_worker = WorkerBuilder::new("rango-tango-2")
.backend(int_store)
.build(send_reminder);
let map_worker = WorkerBuilder::new("rango-tango-1")
.backend(map_store)
.build(send_reminder);
tokio::try_join!(int_worker.run(), map_worker.run()).unwrap();
}§Observability
You can track your jobs using apalis-board.

§License
Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Modules§
- fetcher
- Fetcher module for retrieving tasks from sqlite backend
- queries
- Queries module for sqlite backend Module for various query implementations for the SQLite backend.
- sink
- Sink module for pushing tasks to sqlite backend
Structs§
- Config
- Configuration for the SQL backend
- DbEvent
- Database event emitted by SQLite update hook
- Hook
Callback Listener - Listener for database events emitted by SQLite update hook
- Pool
- An asynchronous pool of SQLx database connections.
- Pool
Connection - A connection managed by a
Pool. - Pool
Options - Configuration options for
Pool. - Shared
Sqlite Storage - Shared Sqlite storage backend that can be used across multiple workers
- SqlContext
- The SQL context used for jobs stored in a SQL database
- Sqlite
- Sqlite database driver.
- Sqlite
Connect Options - Options and flags which can be used to configure a SQLite connection.
- Sqlite
Connection - A connection to an open Sqlite database.
- Sqlite
Storage - SqliteStorage is a storage backend for apalis using sqlite as the database.
Enums§
- Shared
Sqlite Error - Errors that can occur when creating a shared Sqlite storage backend
- Sqlite
Operation - Sqlx
Error - Represents all the ways a method can fail within SQLx.
Traits§
- Connection
- Represents a single database connection.
Type Aliases§
- Compact
Type - CompactType is the type used for compact serialization in sqlite backend
- Sqlite
Pool - An alias for
Pool, specialized for SQLite. - Sqlite
Task - Type alias for a task stored in sqlite backend