I think my grafana is newer and stuff is deprecated
that's unlikely, i'm running 11.2.4 currently.
yes, you'll need to run that exporter against each instance you want to be monitoring.
my setup looks more or less like this: https://github.com/Nothing4You/grafana.lem.rocks
depending on the grafana version you are using you may be running into this bug though: https://github.com/grafana/grafana/issues/96356
fwiw, the estimate number only states the max amount of activities behind. the real number can be lower, but not higher (unless sending is entirely broken on the instance being checked).
each activity being sent has a numeric id in the database. lemmy has an api that returns the id of the last activity that was either successfully sent to an instance or skipped when it didn't need to get sent (e.g. pm to a user on a different instance). there may also be holes in activity ids due to postgres implementation details for auto-incrementing sequence ids.
for determining the highest known activity id to compare it with the last activity id sent to a specific instance, you can just go through the successfully sent ids for all instances in the response and find the highest number across them all. then you can calculate the difference between the highest number and the number for the specific instance.
depending on the lemmy version and timing of the action, it can take up to 30 seconds for the activity queue to deal with new activities, so on a somewhat busy instance the delta is likely rarely going to be zero.
you might find some inspiration from https://breezewiki.com/ - either its codebase directly or using it as an intermediary while scraping
ugh, i didn't notice they're even hiding domains of remote communities for "simplicity" in most cases. that seems so much more dishonest tbh.
this isn't entirely true, they do have some comments on lemmy as well, here are some examples:
it seems to be primarily about their communities not federating though i guess?
and either nobody from there posted a post to a lemmy community yet or maybe it doesn't federate posts currently?
lemmy.ml doesn't use cloudflare, that's strange.
i've also never had issues with this when looking at instances that do use cloudflare.
pretty much, yeah. lemmy has a persistent federation queue instead of fire and forget requests when activities get generated. this means activities can be retried if they fail. this allows for (theoretically) lossless federation even if an instance is down for maintenance or other reasons. if mbin has a similar system maybe they could expose that as well, but unless the system is fairly similar in the way it represents this data it will be challenging to integrate it in a view like this without having to create dedicated mbin dashboard.
lemmy has a public api that shows the federation queue state for all linked instances.
it provides the internal numeric id of the last activity that was successfully sent to an instance, as well as the timestamp of the activity that was sent, and also when it was sent. it also includes data like how many times sending was unsuccessful since the last successful send. each instance only knows about its own outbound federation, but you can just collect this information from both sides to get the full picture.
there is also https://phiresky.github.io/lemmy-federation-state/site to look at the details provided by a specific instance.
it's not just lemmy.world.
of the larger instances, the following have trouble sending activities to lemm.ee currently:
i pinged @[email protected] on matrix about 30h ago already about the issues with federation from lemmynsfw.com, as it was the first one i noticed, but I haven't heard back yet.
at least the image resizing topic has recently been fixed in lemmy, thumbnails sizes are limited (at the time of thumbnail creation) in the latest release. I'd have to look closer at the other stuff, the api part is unlikely to have changed and will affect all frontends, but js part should differ depending on the front end. some instances already use other frontends by default and there is also a replacement for lemmy-ui being worked on (lemmy-ui-leptos), but I don't know how they compare. either.
it should be taken into account though how much of this is cacheable as well, as it will then typically only affect the first load for the static files.
I can totally understand the issues in general though, I've been living with a 64kbps uplink for several years in the past.
based on the creation date advertised by the instance, lemmy.ml exists since 2019-04-20. lemmy.world exists since 2023-06-01.