Azure Cosmos DB is a scalable, globally distributed NoSQL database service from Microsoft. This is an all-inclusive solution and allows you to store and manipulate with key-value, graph, column-family, and document data in one service.
For querying graphs, Azure Cosmos DB supports the Gremlin graph traversal language.
You can find more information about the Cosmos DB graph database here: https://azure.microsoft.com/de-de/services/cosmos-db/.