Azure Cosmos DB for NoSQL vs Elassandra
Azure Cosmos DB for NoSQL
azure.microsoft.comElassandra
elassandra.orgSide by side
| Figure | Azure Cosmos DB for NoSQL | Elassandra |
|---|---|---|
| Price from | Free | — |
| Free plan | Yes | — |
| Free trial | Yes | — |
| Open source | — | — |
| Linux | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 10 | 0 |
| Spec score · Wide-Column Databases | 7.9 (#5) | 7.3 (#10) |
| Integrations | Change feed supports event-driven architectures and streaming pipelines using Azure Functions and Spark. | The documentation lists integration with OpenSearch plugins, OpenSearch Dashboards, and Spark. |
| Scaling | Throughput options include standard provisioned, autoscale provisioned, and serverless models. | Data placement follows Cassandra token ownership, and replica behavior follows Cassandra keyspace replication. |
| What it does | Azure Cosmos DB for NoSQL is a fully managed cloud database using a schema-agnostic JSON document model with SQL-like querying. | Elassandra embeds OpenSearch inside Apache Cassandra so each node serves distributed storage and distributed search. |
Plans
Azure Cosmos DB for NoSQL
- Free tierFree
- 30-day free trialPriced on request
- Standard provisioned throughputPriced on request
- Standard provisioned throughputPrice not published
- Autoscale provisioned throughputPriced on request
- Autoscale provisioned throughputPrice not published
- ServerlessPriced on request
- ServerlessPrice not published
- Azure Cosmos DB free tierFree
- Azure Cosmos DB for NoSQL — standard provisioned throughputPrice not published
In their own words
Azure Cosmos DB for NoSQL
Azure Cosmos DB for NoSQL is a fully managed cloud database built around schema-agnostic JSON documents and SQL-like querying. It supports global data distribution, multi-region writes, and automatic failover, with configurable consistency controls and transactions. Search includes vector and hybrid similarity capabilities for workloads such as retrieval-augmented generation and AI agents. Throughput can use standard provisioned, autoscale provisioned, or serverless models. The service lists SDKs for.NET, Java, JavaScript/Node.js, Python, Go, and Rust. Its change feed can support event-driven architectures and streaming pipelines using Azure Functions and Spark; no-ETL analytical workflows are available through Azure Synapse Link or Fabric mirroring. Microsoft states that NoSQL data has service-level agreements including less than 10 millisecond read and write latency and 99.999 percent availability. A free tier includes 1,000 RU/s and 25 GB of storage for one account per Azure subscription, and a 30-day trial is listed. The Azure Cosmos DB emulator provides a no-cost local development environment for Windows or Linux. The pricing page notes that the selected compute pricing model and API cannot be changed after selection.
Elassandra
Elassandra combines Apache Cassandra’s distributed storage with embedded OpenSearch search on each node. Its maintained line targets Apache Cassandra 4.0.x, OpenSearch 1.3.x, and Java 11. OpenSearch indices map to Cassandra keyspaces, documents to rows, and indexed fields to columns or cells; the current _doc model maps to a Cassandra table. Cassandra remains the durable layer, allowing restart recovery to replay Cassandra state and rebuild a local search view. Applications can search through the OpenSearch HTTP API or CQL, with HTTP responses following OpenSearch style. Data placement uses Cassandra token ownership, while replicas follow keyspace replication. Schemas can be created from OpenSearch indexes or discovered from existing Cassandra schemas through mappings. Integrations listed include OpenSearch plugins, OpenSearch Dashboards, and Spark. Deployment options include tarball, Debian package, RPM, Docker image, and Helm chart. Elassandra is free and open source, with a 30-day trial noted.