Cassandra API – Nonrelational Databases in Azure

Cassandra API

Apache Cassandra is a popular columnar database that stores large volumes of data using a column-oriented schema. Just as with MongoDB and the Azure Cosmos DB API for MongoDB, organizations can migrate their existing Cassandra workloads to the Azure Cosmos DB Cassandra API to take advantage of the premium capabilities that Azure Cosmos DB provides.

Users can query data stored in the Cassandra API using the Cassandra Query Language (CQL) and tools like the CQL shell (cqlsh). Applications can also continue to use existing Cassandra client drivers to interact with Cassandra databases hosted on the Cassandra API.

Gremlin API

The Azure Cosmos DB Gremlin API uses the Apache Tinkerpop graph framework to provide a graph database interface in Azure Cosmos DB. It allows organizations to manage existing and new graph database applications without needing to worry about overhead such as infrastructure, throughput, and availability.

While data is stored as JSON documents as they are with the Core (SQL) API, the Gremlin API enables the data to be queried with graph queries. Applications can query databases hosted on the Gremlin API using the Gremlin query language. More information on the Gremlin query language and using it to query data stored in the Azure Cosmos DB Gremlin API can be found at https://docs.microsoft.com/en-us/azure/cosmos-db/graph/tutorial-query-graph.

Management Tasks for Azure Cosmos DB

Just as with relational PaaS databases in Azure, there are several management tasks that must be taken into consideration for Azure Cosmos DB. These include deploying instances of Azure Cosmos DB, configuring throughput and global distribution, migrating existing on-premises workloads to Azure Cosmos DB, and maintaining data security. The following sections will discuss these tasks in detail, as well as how to troubleshoot common connectivity issues when using Azure Cosmos DB.