At a previous organizion I worked at, about 5-7 years ago, I made very heavy use of Tokyo Tyrant and T. Cabinet (the predecessors of Kyoto Tycoon and KC). We h

At a previous organizion I worked at, about 5-7 years ago, I made very heavy use of Tokyo Tyrant and T. Cabinet (the predecessors of Kyoto Tycoon and KC). We had many instances throughout our infrastructure, and many engineers had at least some knowledge of it. It was the fastest key-value store I'd ever used. I was floored by its speed and relative stability. And the article and comments rightly point out KT's terrible documentation and thin user community on the ground. TT was just the same. This caused a lot of surprising (and mostly undocumented) issues whenever somebody was trying to get onboarded. I was surprised that it was so obscure and so undocumented. Especially considering its speed and simplicity (in terms of getting a basic k-v store set up). I depended a lot on DBA's and DB engineers, our sysadmins, and other engineers with more experience of TT than I had. Usually, whenever I needed to understand a configuration option in detail, deploy a new instance with different characteristics, or optimize an existing instance, I would consult them. I think we had just as much, if not, more, knowledge of this software than any community on the Internet. But all of this raw speed, at the cost of lack of support, lack of documentation or community bit us in the ass, hard. Either the TT/TC service itself crashed, or the host it was running on crashed (I can't remember). Some data was lost because it was designed with no fault tolerance. Most data was recovered from backups. An executive decision was immediately made to move to a different DB, with proper resilience, etc. We quickly moved to a well known, open source, commercially supported system with all the usual value-added proprietary parts. Then the $$$$$ started pouring in to the support contract. At least we had something trustworthy that we could understand, lots of documentation, and good upstream support engineers :-) It's a bit sad to imagine what could have become of TT/TC. I've no idea about KT/KC. They had a LOT of potential. Maybe the potential is still there? Maybe they're project deserve resurrection, at least for educational purposes? At least the source code still exists if anybody is interested enough. Documentation generally consists of reading struct definitions and comments; a couple of decent StackOverflow posts; and now-mostly defunct mailing lists on Google Groups.