Reflector reborn

Franklin Yu · 2023-03-25 04:32:18

Feature request: minimize churn

I want to minimize churn by allowing any subset of top N (after whatever filter I specified). Let’s say N is 6, and the mirrors are A-F; I want Reflector to pick the top 3, let’s say A B C, but if the existing list is A B D (for example C suddenly gets a little faster), I want Reflector to keep the current mirror list of A B D. This way if C and D keep switching between 3rd and 4th place, it doesn’t change the mirror list as often.

This is a preliminary idea, because I don’t have good idea what behavior I want with “--sort”. Would love to learn what you think.

Trilby · 2023-03-25 14:19:24

Franklin, what benefit(s) would that feature provide?

In your example, if C/D keep switching places, they are very similar in the relevant metrics. So why would it matter if the mirror list changed? It could be seen as a "needless" change, but does that carry any cost at all?

Franklin Yu · 2023-03-25 19:10:13

In my case I use etckeeper to track changes in my “/etc/” directory. In theory I can also ignore this file, but it sounds like something I do want to track.

Trilby · 2023-03-25 20:23:06

Thanks that makes sense as a fair use-case for such a feature.

Xyne · 2023-04-10 20:00:17

Reflector would have to read and compare the generated mirrorlist to the user's current mirrorlist and then create some sort of similarity metric to determine if they are similar enough to ignore the new list. That is quite far out of the scope of reflector and will not be implemented.

You would write your own wrapper script to generate a new list in tmpfs, diff that with the existing file and update the file only if you consider the changes significant.

Alternatively, given that the file is dynamically generated, why not just stop tracking it? In what scenario would you need to retrieve an old mirrorlist when you could just generate a new one?

kplant · Yesterday 12:45:32

@Xyne looks like after the most recent repo changes, an update to how reflector is scoring mirrors is needed.

Currently DB_SUBPATH is 'community/os/x86_64/community.db' - this file is now only 45 bytes, could we change this to 'extra/os/x86_64/extra.db'?

Last edited by kplant (Yesterday 13:33:49)

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#176 2023-03-25 04:32:18

Re: Reflector reborn

#177 2023-03-25 14:19:24

Re: Reflector reborn

#178 2023-03-25 19:10:13

Re: Reflector reborn

#179 2023-03-25 20:23:06

Re: Reflector reborn

#180 2023-04-10 20:00:17

Re: Reflector reborn

#181 Yesterday 12:45:32

Re: Reflector reborn

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