bytecode4cosmosdb

This is a small library to support bytecode-based requests with Azure Cosmos DB

A word of caution before proceeding: this is very much a work in progress.

At the moment Cosmos DB only supports script-based requests and the result is returned in GraphSON 1.0 format (see https://tinkerpop.apache.org/docs/3.4.1/dev/io/). Cosmos DB is only compatible with Gremlin.NET 3.4, not with the newer version 3.5 and 3.6 (see https://docs.microsoft.com/en-us/azure/cosmos-db/graph/gremlin-support)

This library converts the bytecode-based request into an Groovy string representation using the GroovyTranslator class taken from the Gremlin.NET 3.5 library (https://github.com/apache/tinkerpop/tree/master/gremlin-dotnet). The returned result is serialized into expected result types of the bytecode based request.

Example: create an edge between to nodes:

Edge newEdge = 
         g.V().Has("person", "first_name", fromName)
          .AddE("friends").To(__.V().Has("person", "first_name", toName))
          .Next();

To use the library you simply have to create a connection to Cosmos DB and instead of using the Gremlin.NET provided DriverRemoteConnection class instanciate the CosmosDbRemoteConnection class

Example:

var connectionPoolSettings = new ConnectionPoolSettings
{
   MaxInProcessPerConnection = 32,
   PoolSize = 4,
   ReconnectionAttempts = 3,
   ReconnectionBaseDelay = TimeSpan.FromSeconds(1),
};

CosmosDbGremlinClientBuilder builder =CosmosDbGremlinClientBuilder.BuildClientForServer(cosmosHostname, cosmosPort, cosmosDatabase, cosmosAuthKey, cosmosCollection);

using (var gremlinClient = builder.WithConnectionPoolSettings(connectionPoolSettings).Create())
{
   GraphTraversalSource g = Traversal().WithRemote(new CosmosDbRemoteConnection(gremlinClient));

   // now we can start to use the bytecode based request
   // e.g.
   Edge newEdge = 
         g.V().Has("person", "first_name", fromName)
          .AddE("friends").To(__.V().Has("person", "first_name", toName))
          .Next();

   Console.WriteLine($"Edge : {newEdge}");

   // ... 
}

Resources

The library can be installed via nuget: https://www.nuget.org/packages/Mathema.Bytecode4CosmosDB/

An example application can be found here: https://github.com/MATHEMA-GmbH/DiningByFriends4CosmosDB