Tesseract. You can use it for your own instance by logging in to it at https://tesseract.dubvee.org/ (which is a bit counterintuitive, because there's also a local Lemmy server there, but it works). Or self-host it of course (see https://github.com/asimons04/tesseract)
It's hit and miss. Some instances are sending the same activity 2 or 3 times, and there's a theoretical maximum on the number of activities that an instance can process, so whether federation of a particular thing happens depends on how whelmed a server is at the exact moment you send it.
I've also seen a comment from lemmy.ml not being acted on by LW, so there are some drops happening.
Yeah, but the community started before the bot at !trendingcommunities@feddit.nl did, lemmy.world had a broken API for much of August (hence the jump), and the subscriber count never changes that much otherwise, but here's what I have:
day
subs
2023-07-24
70
2023-07-26
71
2023-07-28
75
2023-08-03
76
2023-08-05
77
2023-09-03
86
2023-09-04
87
2023-09-05
88
2023-09-11
89
2023-09-29
90
2023-10-08
89
2023-10-14
90
2023-10-15
91
2023-10-18
92
2023-10-21
93
2023-10-22
94
2023-11-12
93
2023-11-17
96
2023-11-19
97
2023-11-20
96
2023-12-15
97
2024-01-05
98
2024-01-10
99
2024-03-08
100
2024-03-10
101
2024-03-11
102
2024-03-15
103
2024-03-22
104
2024-04-04
105
Incidentally, if you want to know how broken the Fediverse is right now, lemmy.ml is the only version that has both of your comments. piefed.social (my instance) has 1, lemmy.one (OP's instance) had the other one, and lemmy.world (where this community is hosted) had none (edit: this was before I made this comment, which has forced a bit of a re-sync).
I think it over-writes every time. If you just want subscriber numbers, I've got data going back to to last July. Let me know what community you're after, and I'll send it to you.
Tesseract. You can use it for your own instance by logging in to it at https://tesseract.dubvee.org/ (which is a bit counterintuitive, because there's also a local Lemmy server there, but it works). Or self-host it of course (see https://github.com/asimons04/tesseract)