We've used Blazegraph at work for a project, and we have used a number of other graph databases.
Blazegraph is a very niche product and requires a lot of time for setting it up and adjusting it for your workload.
If Blazegraph peaks your interest then you should also look into Yarc platform by Cray.
Should you want to look more into graphs, but don't want to spend endless nights just trying to load your data then I would recommend Stardog, which has just been a pleasure to work with.
The promises they make are really tempting. However, when I experimented with Blazegraph last year, it ended up stuck more often than I could count, whether during bulk import or in answering some ad-hoc SPARQL queries.
I can imagine that with extensive tuning, BlazeGraph provides a good database. Just don't expect it to have the polish and convenience of a modern RDBMS or a shiny NoSQL store :)
Their selection "process"[1] was.. not what I'd choose to use, especially since they changed the priorities as they evaluated. But then they abandoned that process[2] so I wouldn't read too much into the evaluation.
Basically as far as I can see, the main reason BlazeGraph was chosen was this: [they] had me out to their office (a house an hour and half from mine)[3]
I'm sure BlazeGraph is fine. We were doing a very similar evaluation at the same time, and the Titan situation screwed us over too. But we took a look at BlazeGraph after Wikidata chose it, and found it pretty rudimentary at that time.
[2] "As you can also see we didn't finish filling them all out. But we've still pretty much settled on BlazeGraph anyway. Let me first explain what
BlazeGraph is and then defend our decision to stop spreadsheet work" https://lists.wikimedia.org/pipermail/wikidata-tech/2015-Mar...
Stardog is great and would be even better with a friendly licensing policy towards indie developers. Their community version is too limited and enterprise version price is per server, contact sales. Current developer version is for testing only.
I would happily pay for a developer license or something like that.
MapGraph -- the GPU-accelerated graph engine -- has been rolled into Blazegraph 2.0, and it looks like this means OLTP and OLAP can be combined into a blazing-fast, single OLXP system.
The original work was funded by DARPA and presented at the
2014 SIGMOD conference in a paper entitled, MapGraph: A
High Level API for Graphs [1]. This work is available in
open source. Later work, in collaboration with the
University of Utah SCI Institute [2] and funded by DARPA,
applied multi-core techniques running on over 750 M cores
on the Titan Supercomputer to extend this to Multi-GPU
traversal with Breadth First Search (BFS). On a cluster of
64 NVIDIA K40 GPUs, it demonstrated a throughput of 32
Billion Traversed Edges Per Second (32 GTEPS), traversing a
scale-free graph of 4.3 billion directed edges in 0.15
seconds, which was featured in a presentation IEEE Bigdata
Conference.
The owner of www.blazegraph.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website."
The graph does need to fit into GPU ram. We use graph partitioning for multi-node, Multi-GPU configurations.
Dijkstra's algorithm which, as mentioned by Davidson et al. [1], is a "sequential algorithm [that] is poorly suited for parallel architectures like GPUs that require large numbers of parallel threads for efficient execution."
Instead, we have variants of the algebraic formulation of the Bellman-Ford algorithm as given in Kepner and Gilbert's book [2].
[1] Andrew A. Davidson, Sean Baxter, Michael Garland, and John D. Owens: "Work-Efficient Parallel GPU Methods for Single-Source Shortest Paths." In Proceedings of the IEEE 28th International Parallel and Distributed Processing Symposium (IPDPS), 2014. http://dx.doi.org/10.1109/IPDPS.2014.45
[2] Kepner and Gilbert: "Graph Algorithms in the Language of Linear Algebra."
Blazegraph is a very niche product and requires a lot of time for setting it up and adjusting it for your workload.
If Blazegraph peaks your interest then you should also look into Yarc platform by Cray.
Should you want to look more into graphs, but don't want to spend endless nights just trying to load your data then I would recommend Stardog, which has just been a pleasure to work with.