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by misframer 4204 days ago
> Still. Aside from that, it is free, and open source and gives hundred times better latency?

It doesn't have the same guarantees. If you need those guarantees, then there's no comparison and it doesn't make sense to compare latencies.

1 comments

I'm not so sure. Have the latencies claimed by FoundationDB been measured on multi-key transactions?

And if you need these guaranties, it seems like "Most of these operations can be implemented on top of the existing RAMCloud features". I would expect it to be possible to implement that and stay well withing the latency budget, provided that a single-key durable write is 100 times faster.

All of the transactions in the test noted in the blog are multi-key transactions. (20 key updates)
When claiming the 14.4MHz number, is that per 20-key update? Or a single key update in the 20-key update? And what's the latency on the 20-key update?
The writes we are measuring are individual keys, modified atomically in transactions of 20 keys at a time. So this test is doing 14 million writes per second as 720 thousand transactions per second.
Multi-key transactions means coordination. Coordination is not cheap. You'll be paying a hefty cost somewhere.