
Building With Workers KV, a Fast Distributed Key-Value Store - jgrahamc
https://blog.cloudflare.com/building-with-workers-kv/
======
skrebbel
I love it and want to use it, but two announcements of a new cloud hosted
distributed DB and no mention of how consistency works or how conflicts are
handled worries me a bit.

Maybe one of the cloudflare people that read HN can shed some light on this?
What happens when I write to the same key simultaneously from multiple workers
and/or multiple edge nodes?

~~~
aaaaaaaaaab
They write it in the description: eventual consistency with global consistency
within 10 sec.

~~~
zzzcpan
That's rather vague definition. And is also wrong. They obviously can't
guarantee global consistency within 10 sec, as that would require consensus
which is impossible to guarantee in bounded time and they probably don't even
use any consensus algorithm at all, as that would be pointless for a CDN.

~~~
kentonv
Yes, in the presences of a network partition, propagation can take arbitrarily
long. But, that would be classified as an outage. Knowing the typical non-
outage delay is useful.

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sephware
> _Reading values from Workers KV is designed to have the same reliability as
> reading static files, making it much less likely to become unavailable than
> a traditional database. It’s designed to have the same performance as
> reading a file cached within our network, close to your users, giving it the
> speed of serving a static file as well._

I wonder how this kind of speed is achieved with an API that has to go over
the network? Even if the round trip is short such as between two AWS services,
there's always at least some latency.

~~~
manigandham
Reading cached files goes over the network too. CDN servers share the cache
load and have just 1 or a few copies per datacenter that are served by every
machine there.

It's likely that this KV store is built on top of the existing cache storage
layer, which would also explain the eventual consistency and high-reads with
low-writes.

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manigandham
Fantastic development. Cloudflare is making some great progress recently with
workers.

Listing keys in a namespace and/or TTLs would be nice with KV.

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na412
Going a bit off-topic, I can't access this CloudFlare blog using a Tor browser
(using the "standard" security level) without a CAPTCHA.

Didn't we discuss just last week an article[0] by CloudFlare where they said
they'd solved this problem and Tor users wouldn't need to solve CAPTCHAs for
CloudFlare-fronted services anymore?

What happened to that? I've actually seen way more CloudFlare CAPTCHAs through
Tor since that article came out.

[0]
[https://news.ycombinator.com/item?id=18031649](https://news.ycombinator.com/item?id=18031649)

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cremp
So... A hosted Consul?

