RonDB
RonDB is an open-source distributed storage engine for real-time applications, and a fork of MySQL NDB Cluster.
What RonDB is
RonDB is an open-source distributed storage engine for real-time applications, and a fork of MySQL NDB Cluster. Its shared-nothing design supports up to 1 PiB of storage, with online horizontal and vertical scaling for both storage and MySQL-server compute. Applications can use the MySQL Server API for SQL-compatible access and parallel queries. Through MySQL-server support, RonDB provides ACID transactions; in-memory data is persisted using REDO logs and checkpoints. The project describes its performance aims as low latency, high availability, high throughput, and scalable storage. It also supports AI application storage integrated with Spark and Kafka, while Rondis implements a Redis server using RonDB storage and the Redis wire protocol. Deployment options include local testing, Docker, cloud deployments using your own AWS, Azure, or GCP credentials, and on-premises deployment by inquiry. Replication can be synchronous active-active across availability zones or asynchronous across regions with conflict resolution. RonDB is used as the online feature-store database for low-latency, high-availability machine-learning applications in Hopsworks. It is free and supports Linux, API, and self-hosted use.
Good
- Supports up to 1 PiB of storage.
- Online horizontal and vertical scaling are supported.
- SQL-compatible access uses the MySQL Server API.
- Offers synchronous and asynchronous replication options.
- Free, open-source software with self-hosted deployment.
Watch out
- Uses read-committed isolation and lacks range locks.
- On-disk encryption does not cover backups.
- Cloud deployment uses your own provider credentials.
Who it suits
RonDB is suited to teams building real-time applications or low-latency machine-learning feature stores. Its deployment options serve teams considering local, container, cloud, or on-premises environments.
Verdict
RonDB offers distributed storage with SQL access, scaling, and replication options for real-time workloads. Its read-committed isolation and lack of range locks are important transactional limits to account for.
Plans and prices
From RonDB's own pricing page, checked 1 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Serverless RonDB via Hopsworks | Free | quotas on Feature Groups (tables) · quotas on memory usage |
The facts
Each one read from RonDB's own pages, with the date it was checked.
What it does
- AI integrations
- RonDB supports AI application storage integrated with Spark and Kafka.checked 1 Oct 2026
- Deployment options
- RonDB can be tested locally, run in Docker, managed in AWS, Azure or GCP using own cloud credentials, or deployed on-premises by inquiry.checked 1 Oct 2026
- Encryption at rest
- RonDB supports encryption of on-disk data including local checkpoints, tablespaces, REDO logs and UNDO logs, but not backups.checked 1 Oct 2026
- Performance model
- RonDB targets low latency, high availability, high throughput and scalable storage, which it calls LATS.checked 1 Oct 2026
- Primary use case
- RonDB is used as the online feature-store database for low-latency, high-availability machine-learning applications in Hopsworks.checked 1 Oct 2026
- Redis compatibility
- Rondis implements a Redis server using RonDB storage and the Redis wire protocol.checked 1 Oct 2026
- Replication
- RonDB supports synchronous cross-availability-zone active-active replication with 1 to 3 replicas and asynchronous cross-region replication across clusters with conflict resolution.checked 1 Oct 2026
- REST security
- The RonDB REST API supports Hopsworks API-key authentication and recommends TLS when API keys are used.checked 1 Oct 2026
- Scaling
- RonDB supports online horizontal and vertical scaling for storage and MySQL-server compute.checked 1 Oct 2026
- SQL access
- Applications can access RonDB through the MySQL Server API with SQL compatibility and parallel query support.checked 1 Oct 2026
- Storage scale
- RonDB supports up to 1 PiB of storage.checked 1 Oct 2026
- Transactional limit
- RonDB uses read-committed isolation and does not support range locks.checked 1 Oct 2026
- Transactions
- RonDB is ACID compliant through MySQL-server support, with in-memory data persisted using REDO logs and checkpoints.checked 1 Oct 2026
- What it does
- RonDB is a distributed, shared-nothing storage engine and an open-source fork of MySQL NDB Cluster for real-time applications.checked 1 Oct 2026
The company
- Maker support
- RonDB is brought to you by the RonDB team at Hopsworks AB, which provides dedicated support for high-performance online feature-store requirements.checked 1 Oct 2026
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