Rendered with Parsoid

Talk:CDN

From Wikitech
Latest comment: 9 months ago by BCornwall in topic Is it time to move this out of the User page?
Jump to navigation Jump to search

Should we include software version numbers?

This seems easy to forget to update, causing out-of-date information. Would it be simpler to just say the software used without the version numbers? BCornwall (talk) 21:14, 6 February 2023 (UTC)Reply[reply]

I don't think so. Ideally even what are we using (HAProxy, ATS or varnish) should be irrelevant Vgutierrez (talk) 09:39, 17 February 2023 (UTC)Reply[reply]
Yes Done BCornwall (talk) 16:13, 17 February 2023 (UTC)Reply[reply]

What happens when HAProxy closes a connection that's already reached Varnish/ATS?

When talking with cdanis about the rate limiting, he mentioned:

<cdanis> doesn't cancel any of the requests running in Varnish/MW/etc
<brett> So what happens with the requests running in varnish/mw/etc? Are those returned as normal or do they go to a black hole?
<cdanis> brett: I haven't checked but I think haproxy closes the connections with those requests pending; not 100% sure what Varnish does from there, or what happens in the applayer, however I suspect they keep running
<rzl> within MW at least, I'm pretty sure once the request has started, it'll continue until we try to send the first response byte and get an error
<rzl> I wouldn't be surprised if proxy components like Varnish, or even Envoy on the appserver, release their resources for that request more promptly, but I don't know what each of them does
<rzl> (actually I guess "try to send the first response byte and get an error" depends on Envoy's behavior in particular)
<rzl> but MW will proceed, until either TTFB or the entire request, as normal

Is this information that is relevant to this article? BCornwall (talk) 20:20, 28 February 2023 (UTC)Reply[reply]

Removing individual component detailing in favor of more consumer-based, factual information

Vgutierrez: I got some useful feedback from bblack regarding the overall structure of the article based on the audience:

<bblack> the "audience" for this, I assume, is application-layer folks? this is more or less the start of documenting our "contract" or whatever?
<bblack> in which case, I kind of question the splitting of it by layers in general
<bblack> e.g. the "caching logic" at the bottom under BCL - the FCL has to follow the same rules, too.
<bblack> and the headers set from the TLS and FCL layers, well, it's the BCL that carries them through to the app.
<bblack> yeah, plus long-term-thinking: we may change the number of layers and how they're implemented (and have in the past), but we try to keep the /behavior/ invariant from the outside
<bblack> so maybe just a brief into section that talks about the current structure of things (i.e. that it's currently implemented in 3 layers using haproxy,varnish/ats - because this /is/ useful to know when debugging things or thinking about things in the present).
<bblack> but then talk about headers/protocols/etc for the CDN as a whole (many of these are rules that carry through all layers, or must be implemented in more than one, or may move where they're implemented at in the future)

I think this makes sense and it's worth restructuring this by removing all the software destinction and just say "this is what you will receive from our side of things". BCornwall (talk) 18:26, 27 March 2023 (UTC)Reply[reply]

+1 :) Vgutierrez (talk) 18:36, 27 March 2023 (UTC)Reply[reply]
Yes Done - It still needs improvements but at least the structure is now there. BCornwall (talk) 21:33, 27 March 2023 (UTC)Reply[reply]

Is it time to move this out of the User page?

I don't want it to be forgotten/lost :) BCornwall (talk) 20:13, 18 May 2023 (UTC)Reply[reply]