mongoengine-rw-router 0.0.1

MongoDB read-write separation router for mongoengine ODM with transaction-aware and consistent hash routing

Mongoengine Read-Write Router

A MongoDB read-write separation solution for mongoengine ODM, inspired by the django-rw-router architecture.

This library routes write operations to the primary database and read operations to replica set members, with configurable consistency strategies.

Features

• Automatic read-write routing - Writes go to primary, reads go to replicas
• Multiple consistency strategies - random, transaction-aware, consistent hashing
• Read-after-write consistency - Ensures you see your own writes
• Request context tracking - Thread-safe context using contextvars
• Web framework integration - Middleware for FastAPI, Flask, and Django
• Force primary reads - Explicit control when you need fresh data
• Write operation tracking - Automatic context updates on writes

Installation

pip install mongoengine-rw-router

Quick Start

from mongoengine import connect, Document, StringField, IntField
from mongoengine_rw_router import (
    RwDocumentMixin,
    configure,
    MongoRouterMiddleware,
)

# 1. Set up connections
connect(db="myapp", alias="default", host="mongodb://primary:27017")
connect(
    db="myapp",
    alias="replica1",
    host="mongodb://replica1:27017",
    read_preference=ReadPreference.SECONDARY_PREFERRED,
)

# 2. Configure router
configure(
    primary_alias="default",
    replica_aliases=["replica1"],
    strategy="transaction_aware",
)

# 3. Define model with routing
class User(RwDocumentMixin, Document):
    name = StringField()
    email = StringField()
    age = IntField()

    meta = {"db_alias": "default"}

# 4. Use it!
user = User.objects.first()  # Reads from replica
user.age = 25
user.save()  # Writes to primary

License

MIT

Credits

Inspired by django-rw-router