lilota 0.4.0

A lightweight solution for long-running tasks

lilota

lilota is a lightweight Python library for executing long-running tasks in the background without the complexity of full task queue systems like Celery or RabbitMQ.

It is designed for simple, asynchronous task execution with minimal setup and overhead.

• lilota
  • Features
  • When to use lilota
  • Installation
  • Quick example
    • Define input and output models
    • Create a lilota instance
    • Register a background task
    • Start lilota
    • Schedule a task
  • Task persistence
  • Shutdown
  • Full example

Features

• Run long-running tasks in separate processes
• Simple API and minimal configuration
• Persistent task state stored in a database
• No message broker required
• Suitable for web applications and background jobs

When to use lilota

Use lilota when your application needs to run tasks that take time, such as:

• image or file processing
• report generation
• sending emails
• heavy computations

Instead of blocking the request, lilota lets you start the task in the background and immediately return a response to the user.

Installation

pip install lilota

Quick example

Define input and output models

from dataclasses import dataclass
from lilota.core import Lilota

@dataclass
class AddInput:
  a: int
  b: int

@dataclass
class AddOutput:
  sum: int

Create a lilota instance

lilota = Lilota(
  db_url="postgresql+psycopg://postgres:postgres@localhost:5432/lilota_sample"
)

In this example we use a url to a postgres database. lilota uses SQLAlchemy and therefore all databases that are supported by SQLAlchemy can be used here.

Note: SQLite is an excellent database in many scenarios, but for a multiprocessing application like lilota, it has fundamental limitations that often make it a poor fit.

Register a background task

@lilota.register("add", input_model=AddInput, output_model=AddOutput)
def add(data: AddInput) -> AddOutput:
  return AddOutput(sum=data.a + data.b)

Start lilota

lilota.start()

Schedule a task

task_id = lilota.schedule("add", AddInput(a=2, b=3))

Task persistence

schedule will directly execute our function in a separate process. Information about the executed task are stored inside the database in the task table:

Columns	Notes
id	Primary key
name	Task name
pid	Process ID
status	pending, running, completed, failed, cancelled
progress_percentage	Progress (0-100)
start_date_time	Start timestamp
end_date_time	End timestamp
input	Serialized input data
output	Serialized output data
exception	Exception details if the task fails

Shutdown

lilota.stop()

lilota will wait for running tasks to finish before exiting.

Full example

The full example can be found here: https://github.com/tobiasroessler/lilota-sample/blob/main/src/2-add-two-numbers.py