Implementing Realm Sync and Local Cohabitation

Setting Up Realm Sync

• Create a Realm App: Start by creating a Realm app in the MongoDB Atlas dashboard. This app will serve as the bridge between your local Realm database and MongoDB Atlas.
• Configure Sync Rules: Define the synchronization rules that specify which data will be synchronized between the local database and MongoDB Atlas. This includes setting up permissions, data partitioning, and conflict resolution strategies.
• Integrate Realm SDK: Integrate the Realm SDK into your mobile or web application. This SDK provides the necessary APIs for interacting with the local Realm database and managing the synchronization process.
• Implement Data Models: Define your data models using the Realm SDK. These models represent the data structure that will be stored locally and synchronized with MongoDB Atlas.
• Start Sync: Initiate the synchronization process by calling the appropriate APIs provided by the Realm SDK. This will establish a connection to MongoDB Atlas and start the data sync process.

Here’s a basic example in Swift for an iOS application:

import RealmSwift

// Define your Realm object model
class Task: Object {
    @objc dynamic var id = 0
    @objc dynamic var name = ""
    @objc dynamic var completed = false
}

// Initialize Realm
let realm = try! Realm()

// Open a Realm file and start a Sync session
let app = App(id: "your-app-id")
let user = app.currentUser!

let configuration = user.configuration(partitionValue: "your-partition")
let syncedRealm = try! Realm(configuration: configuration)

Implementing Local Cohabitation

• Install MongoDB: Install MongoDB on the same device or environment where your application is running. This local instance will serve as the local data store.
• Configure Connections: Configure your application to connect to both the local MongoDB instance and MongoDB Atlas. This will allow you to manage data access and synchronization between the two databases.
• Define Data Flow: Design the data flow between the local MongoDB instance and MongoDB Atlas. This includes deciding which data should be stored locally and which should be synchronized with the remote server.
• Implement Synchronization Logic: Implement the necessary logic to handle data synchronization between the local MongoDB instance and MongoDB Atlas. This may involve using custom scripts or third-party tools to ensure data consistency.
• Test and Optimize: Test your application to ensure that data synchronization and local data access are working as expected. Optimize the configuration to improve performance and reduce resource usage.

MongoDB Realm is a mobile database solution that simplifies data synchronization and provides real-time capabilities for mobile and web applications. Realm Sync ensures that data is seamlessly synchronized between the client and server, allowing for offline-first experiences. However, developers often need to balance the use of Realm Sync with local data storage and access patterns. This article explores how to manage Realm Sync and local data cohabitation in MongoDB to build efficient and robust applications.