Titan is a free, open source database that is capable of processing extremely large graphs and it supports a variety of indexing and storage backends, which makes it easier to extend than some popular NoSQL Graph databases.

This docker image instantiaties a Titan graph database that is capable of integrating with an ElasticSearch container (Indexing) and a Cassandra container (Storage).

The default distribution of Titan runs on a single node, so I thought it would be helpful if there was a modular way at runtime to hook up Titan to its dependencies.

Enter Docker. Now it is possible to run Titan and it's dependencies in separate Docker containers.

This container is using Titan 0.5.0. Please refer to its page for more information.

Tinkerpop is a vendor-independent API specification for manipulating and access Graph databases.

Rexster is a service that provides protocols for accessing a graph database. Currently it supports two protocols: - REST over HTTP: Human-readable and good for testing - RexPro: Binary Protocol for performence

If you'd like to avoid vendor lock-in, then I'd recommend using Rexster as the API for accessing your Graph database. It has support for popular graph databases, so you can avoid refactoring your code. Take a look at Tinkerpop Gremlin for a Groovy-DSL for querying graphs to see how RexPro and Gremlin provide syntactical elegance to query graphs.

The minimum system requirements for this stack is 1 GB with 2 cores.

docker run -d --name es1 dockerfile/elasticsearch
docker run -d --name cs1 poklet/cassandra
docker run -d -P --name mytitan --link es1:elasticsearch --link cs1:cassandra apobbati/titan-rexster

8182: HTTP port for REST API

8183: RexPro for native access (Binary protocol)

8184: JMX Port (You won't need to use this, probably)

You can read more about it in the Rexster documentation.

To test out the REST API (over Boot2docker):

curl http://localhost:<port-mapped-to-8182>/graphs/graph/vertices

I've tested this container with the following containers:

- poklet/cassandra: This is the Cassandra Storage backend for Titan. It scales well for large datasets.
- dockerfile/elasticsearch: This is the ElasticSearch Indexing backend for Titan. It provides search
	capabilities for Titan graph datasets.

In the near future, I'd like to add support for:

- Scaling/Clustering Cassandra and ElasticSearch backends.
- External volumes for persistent data.
- Security between Titan and its backends.
- Example application stack integrating with Titan.