{"id":4252,"date":"2024-10-25T11:03:09","date_gmt":"2024-10-25T18:03:09","guid":{"rendered":"https:\/\/www.couchbase.com\/blog\/migrate-mongodb-atlas-to-couchbase\/"},"modified":"2024-10-25T11:03:09","modified_gmt":"2024-10-25T18:03:09","slug":"migrate-mongodb-atlas-to-couchbase","status":"publish","type":"post","link":"https:\/\/www.couchbase.com\/blog\/migrate-mongodb-atlas-to-couchbase\/","title":{"rendered":"How to Migrate MongoDB Device Sync (Realm) Apps to Couchbase Capella App Services"},"content":{"rendered":"\n

The developer community has expressed significant concern following <\/span>MongoDB Atlas\u2019s deprecation announcement<\/span><\/a> of their edge and mobile capabilities. In an earlier <\/span>post<\/span><\/a>, we explored why Couchbase Mobile is a strong alternative for supporting your offline-first data sync requirements.<\/span><\/p>\n\n\n\n

In this post, we\u2019ll offer a technical overview of what a typical migration from MongoDB Atlas Device Sync to Couchbase looks like. While we\u2019ll be focusing on <\/span>Capella<\/span><\/a>, our fully managed DBaaS solution, the concepts discussed will apply just as well to self-managed deployments of <\/span>Couchbase Server<\/span><\/a> and <\/span>Couchbase Mobile<\/span><\/a>.<\/span><\/p>\n\n\n\n

Migration considerations<\/h2>\n\n\n\n

When planning to migrate your MongoDB Device Sync (Realm) application to Capella App Services, it\u2019s important to take a holistic approach, considering both the cloud server-side components and the mobile application aspects.<\/span><\/p>\n\n\n\n

NOTE<\/b>: <\/span>The items listed below are not intended to be prescriptive but represent common considerations.<\/b> Each application is unique, so the migration process must be customized to meet the specific requirements of the application.\u00a0<\/b><\/p>\n\n\n\n

You can begin with <\/span>Couchbase Capella’s Free Tier<\/span><\/a>, which includes Capella App Services\u2014our hosted data sync solution. Once you’ve validated your migration and are ready for production deployment, you can upgrade to one of <\/span>our paid tiers<\/span><\/a>.<\/span><\/p>\n\n\n\n

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1. Data modeling<\/h3>\n\n\n\n

MongoDB and Couchbase are both document databases and store data in JSON format. However, MongoDB represents JSON documents in binary-encoded format called BSON using<\/span> extended JSON specification<\/span><\/a>. So while Couchbase can work with\u00a0 documents in extended JSON format as you will see later, it will be simpler to work with regular JSON documents.\u00a0<\/span><\/p>\n\n\n\n

Use this opportunity to determine the right data model for your migrated application and how you can organize it with <\/span>buckets<\/span><\/a>, <\/span>scopes and collections<\/span><\/a>. For instance, you may decide to skip or rename properties, which is fairly trivial to do with Couchbase <\/span>Eventing Service functions<\/span><\/a>.\u00a0<\/span><\/p>\n\n\n\n

2. Configure Capella cluster<\/h3>\n\n\n\n

Deploy <\/span>your Capella cluster<\/span><\/a> and configure it per your application needs. The configuration would minimally include installation of the relevant services such as Query, Search etc., setting up cluster access credentials and <\/span>setting up an IP Address allow list<\/span><\/a>. Setting up an allowed IP address is typically necessary only for testing or evaluation purposes. In a production environment, you will likely configure cluster access via private networks, such as <\/span>VPC Peering<\/span><\/a> or <\/span>Private Links<\/span><\/a>.\u00a0<\/span><\/p>\n\n\n\n

3. Data migration<\/h3>\n\n\n\n

To migrate data from a MongoDB Atlas cluster to a Capella cluster, you have several options. Your choice will depend on whether you’re performing a one-time, offline data migration or opting for a more complex online data migration. The online data migration typically requires bi-directional data synchronization between the MongoDB Atlas and Couchbase Capella clusters, especially if both are actively serving applications during the transition.<\/span><\/p>\n\n\n\n

Here are a few common options:<\/span><\/p>\n\n\n\n

Use export\/import utilities – <\/strong>Export<\/span><\/a> your MongoDB collections and import them into Capella using the <\/span>cbimport<\/span><\/a> tool. If your data is in extended JSON format, you’ll need to perform data transformation using <\/span>Eventing service functions<\/span><\/a> during the import process. Even if the data is in JSON, you may need to run data transformation if your target data model is not identical to the source. This approach is ideal for a one-time data migration.<\/span><\/p>\n\n\n\n

Use enterprise data migration tools – <\/strong>Leverage enterprise-grade tools like <\/span>MOLO7\u2019s GlueSync for Couchbase<\/span><\/a> to migrate data. A tool like GlueSync offers robust, scalable support for data migrations including hot and cold migrations. Check out this <\/span>video<\/span><\/a> for an overview of its capabilities and how it can assist in migration.<\/span><\/p>\n\n\n\n

Open source tooling – <\/strong>You can try our open source community supported Couchbase utility, <\/span>cbmigrate<\/span><\/a>, to migrate data over. This works well for simple data migrations. The tool is integrated into popular Couchbase IDE extensions for <\/span>VSCode<\/span><\/a> and <\/span>JetBrains<\/span><\/a>. So if you are a developer who is building applications using these IDEs, then you should consider this option.\u00a0<\/span><\/p>\n\n\n\n

Once data is migrated, you may have to <\/span>create suitable indexes <\/span><\/a>on your Capella cluster.<\/span><\/p>\n\n\n\n

4. Configure Capella App Services<\/h3>\n\n\n\n

App Services<\/span><\/a> is the managed backend service responsible for offline-first data sync. After setting up your cluster, you’ll need to deploy App Services to connect it to the configured cluster. The setup of App Services will vary significantly based on the specific requirements of your application.<\/span><\/p>\n\n\n\n

Take the time to assess your application’s requirements and ensure it is configured properly.\u00a0<\/span><\/p>\n\n\n\n

There isn’t an auto-migration tool available for this step. But we\u2019ve got you covered. Refer to the <\/span>simple getting started guide<\/span><\/a>, which covers important configuration aspects using a sample dataset. This guide will help you get acquainted with the core concepts and you can adapt that for your application.<\/span><\/p>\n\n\n\n

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Deploy App Endpoints\u00a0<\/span><\/h4>\n\n\n\n

An <\/span>App Endpoint<\/span><\/a> is a representation of your application within Capella App Services. It represents the endpoint with which your mobile application will sync data. You must configure at least one App Endpoint on your App Services cluster. Each App Endpoint is associated with a bucket, a scope and a unique subset of collections within that scope.<\/span><\/p>\n\n\n\n

Configure App Endpoints\u00a0<\/span><\/h4>\n\n\n\n

Setup Authentication Mechanism – <\/b>By default, all App endpoints are protected using Basic Authentication. You have the option to set up advanced authentication mechanisms<\/a>.<\/p>\n\n\n\n

Configure Mobile App Users (& Roles) –\u00a0<\/b>Configure one or more <\/span>application users<\/span><\/a> and optionally roles. These are the users who are authenticated to sync data with App Services. In a production app, you are likely going to use <\/span>Admin REST API<\/span><\/a> for configuring users, or use the auto-register user capabilities if you have configured <\/span>Open ID Connect (OIDC) for authentication<\/span><\/a>.<\/span><\/p>\n\n\n\n

Setup Access Control –\u00a0<\/b>This is one of the most crucial elements of the App Endpoint configuration. Here, you define the user’s level of access (read\/write) by specifying a JavaScript function. Access control is made possible through a unique and powerful concept known as “<\/span>channels<\/span><\/a>.” By default, all documents within a collection are associated with a channel that shares the same name as the collection. As a result, a user who is granted access to a channel with the collection’s name automatically gains read access to all documents in that collection. Check out our <\/span>docs<\/span><\/a> to learn more about Access control and Validation.<\/span><\/p>\n\n\n\n

Once you have configured your App Endpoint, you are ready to <\/span>connect to it<\/span><\/a> and sync data from your Couchbase Lite enabled application.<\/span><\/p>\n\n\n\n

5. Migrate your Realm application<\/h3>\n\n\n\n

Now that your backend is set up, it’s time to migrate your Realm SDK application to <\/span>Couchbase Lite<\/span><\/a>. Realm is an object-oriented database, whereas MongoDB is a JSON document store, which requires transforming BSON documents into Realm objects. In contrast, Couchbase Lite is a full-featured embedded JSON document store that eliminates the need for transformation.<\/span><\/p>\n\n\n\n

Migrating your Realm app will involve rewriting your application\u2019s model layer (or Data Access Layer) to use Couchbase Lite’s SDK in the corresponding language.<\/span><\/p>\n\n\n\n

Check out our <\/span>comparison guide<\/span><\/a> that compares MongoDB Device Sync SDK with Couchbase Lite. Here are some language specific guides:<\/span><\/p>\n\n\n\n