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Comment by userbinator | Hacker News Reader

I'm curious what VMware uses this for.

I don't how much I can say since I work for VMware, but it's finding new uses all the time and I've personally brought it up with other teams.

I'd known of it a while before seeing a presentation on how one service team used it. They had a stream processing problem where they were beginning to lag the input by up to an hour. With differential datalog the lag dropped to sub-second.

It's seriously cool technology.

I'm told it's primarily used for "networking stuff and big data processing", but "log processing" and "network switches" were also mentioned as (I assume active) use-cases.

Section 4 of [1] lists applications, including OVN, but it appears to be used primarily for experimental or research projects at the moment, but that should change given enough time… maybe?

1: https://github.com/vmware/differential-datalog/blob/master/d...

https://twitter.com/Ben_Pfaff/status/1047905803250724865

Yes, and I'm really impressed with what we've been able to do with it in OVN lately. The patches aren't posted yet (probably Monday) but (with Leonid Ryzhyk's help) I managed to take one benchmark from about 110 seconds in the C version of OVN to about 35 seconds with DDlog.

We have other internal-to-VMware use cases for DDlog. The OVN use case is the one that's easiest to evangelize since it's all open source.

Maybe for hot migration?

Pretty sure not. Posted in reply to the sibling. This is a VMware research project but looks like the target use case is for OVN:

https://blogs.vmware.com/opensource/2018/07/26/open-source-o...

https://blogs.vmware.com/research/2020/12/07/whats-new-diffe...

https://twitter.com/Ben_Pfaff/status/1047905803250724865

Oh interesting, thanks!

Speaking with my VMware hat on, I don't know of use cases there.

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