I discussed some more with Lukas and looked around a bit.
Titan is basically the link between TinkerPop (graph API) and Cassandra.
I may have jumped in conclusion but:
- Datastax (the company behind Cassandra) bought ThinkAurelius (the company behind Titan)
- Since then Datastax built a product "inspired by Titan", a graph DB with TinkerPop and Cassandra. TThe product is closed-source and completely targeted to Cassandra. Datastax has no real incentive to maintain Titian as it competes with their product and all engineers stopped contributing to it.
- Last release of Titan was in Sept 2015 (they used to release ~ every 3 months)
- While the community is relatively active, no Pull request was approved after June, and we don't know about any fork that is well maintained
- It's a fairly large and complex piece of code, too large and too narrowed for us to take over.
Conclusion: medium/long term Titan is no longer an option.
The other concern is that there is no good solution to store to Cassandra which is the only storage dependence for Hawkular Services today (and was an important requirement).
So we have to make a difficult choice here but we don't seem to have many options if we stick with TinkerPop at least...
According to Lukas, Sqlg is a good option for the following reasons:
- Performance
- Size/complexity
- The "community" is really small but the lead developer is responsive (and in the case he stops, it would be easier to fork and maintain).
The big drawback is that for production we would require Postgres (for non-prod or for Hawkular Services users who don't use the inventory service, we can use the embedded H2).
Thoughts ?
Thomas