Apache River hasn't gone much farther from the last time I looked at it, but I liked the bare-bones reference implementation aspect. GigaSpaces seems a bit thick for my tastes and seems to be tightly coupled with their application server. I thought Blitz JavaSpaces might be a better fit, especially if I could use their fault tolerant edition.
I was able to get Blitz up and running then configured it to do unicast discovery to a pre-existing Jini registrar without a problem. I was having problems getting my client to connect in its security context, so I decided to dig a little deeper. As I did I also kept an eye towards fault-tolerance, but found that branch seemingly suspended. I later found a post from the author indicating he didn't really see a good motivation for moving forward with his fault-tolerance work:
In my spare moments I've been doing a re-implementation but the fact of the matter is that it's not a trivial problem to solve (though I believe I do have a solution). And here's the rub, this work doesn't pay the bills which means that it's going to take a long time to implement because I have to do a day's work first. For those who don't know, most of Blitz has been written during time between periods of employment - not over weekends and evenings as you might expect.
This presents me with a problem - users seem to want this feature but I'm struggling to see doing this as a good thing. Here's some of my reasons:
- I'd be building a significant feature which will, judging by demand, make a lot of money for those who use it but zilch for me.
- Not only do I earn nothing from this venture but I have to earn a significant amount of cash just to allow me time to develop the feature. Basically, I'd be financing everybody else's money making ventures.
- One of GigaSpaces key value adds is the clustering/replication feature - they are fully commercial and need to earn a crust plus they're one of only a few credible companies that can provide corporate grade support for JavaSpaces. Were I to do this work for Blitz I'd maybe be damaging the market I've been helping to create.
Right now, I feel like the price of this piece of work is too high for me personally and for others in the commercial JINI world (and like it or not they are an important element in any future success for JINI). I can see why Blitz users might want this feature - they can avoid paying Gigaspaces a license for starters.
So... it seems like the development of an enterprise ready Blitz isn't in the cards. Casually strolling through Wikipedia's definition of a Tuple space brought up Fly Object Space, a tuple space that is not a JavaSpace implementation. While it doesn't fit into the Jini realm I know and love, it is a more minimalistic implementation of an object space that fits my desire of something smaller and to-the-point. It doesn't appear to support replication or fail-over on the non-commercial level, but I'm checking to see if there are plans to support it on a commercial level.
It's tough. I need an object space that has a minimalistic implementation, has a small footprint and can at least run active/passive for fault tolerance. Maybe I might have to dust off my old Terracotta instance and try out SemiSpace.
EDIT: Be sure and see Nati Shalom's comments following this post.