| 24 Mar 2025 |
 emily | so current growth rate is ~6.56 TiB/month, so cache growth size would be 1.15–1.3× current? | 14:20:34 |
| emily | has there been any work or even proposals for things to reduce cache size growth other than "GC everything" that would have anything like a 15–30% impact/ | 14:24:43 |
| emily | * has there been any work or even proposals for things to reduce cache size growth other than "GC everything" that would have anything like a 15–30% impact? | 14:24:46 |
 hexa | Download BucketSizeBytes-2023_12_26_00_00_00-2025_03_23_00_00_00-UTC.csv | 14:28:22 |
| hexa | daily bucket sizes for the last 36 months | 14:28:31 |
| hexa | * daily bucket sizes for the last 15 months | 14:29:00 |
| hexa | * that is a manual thing iirc | 14:29:29 |
 Vladimír Čunát | I've certainly heard proposals like GC everything that's never "been in a channel". | 14:29:58 |
| emily | right, that's what i meant re: GC | 14:34:40 |
 ElvishJerricco | this seems to indicate the cache grows by like 300G a day, doesn't it? | 14:43:05 |
| hexa | https://docs.google.com/spreadsheets/d/1KA2tbPsi1kQuwlHJC89iWUQBXPv6p1N3n0t73bbK7n4/edit?usp=sharing | 14:44:00 |
| emily | about in line with the 6.56 TiB/month figure | 14:45:16 |
| emily | so seems accurate | 14:45:25 |
| ElvishJerricco | hexa (signing key rotation when): i think your columns are backward; you have the IA labeled as standard and vice versa | 14:45:30 |
| hexa | lol 🙂 | 14:45:38 |
| hexa | feel free to edit | 14:45:41 |
| hexa | at least the trendline for daily added goes down 😄 | 14:50:37 |
| emily | now add the first day with an eval that adds ~500 GiB of NVIDIA :P | 14:51:56 |
| hexa | I'm still waiting for the rocm kernel build that exceeds 24 hours | 14:53:42 |
| hexa | but apparently https://github.com/NixOS/nixpkgs/pull/367695 has not landed yet | 14:54:24 |
| hexa | * but apparently https://github.com/NixOS/nixpkgs/pull/367695 has not landed so far | 14:54:33 |
| Vladimír Čunát | That would be ~1 TB / month just from staging* rebuilds for this. | 14:59:17 |
| emily | right. I commented as much on the RFC. (from the RFC diff after the conversation earlier it seems like your earlier comment was misinterpreted as "the current normal cache growth rate is 2 TB/month compared to this being 700 GB one time"?) | 15:00:13 |
| emily | (rather than "this would add 2 TB/month rather than 700 GB one time, because of rebuilds") | 15:00:31 |
| emily | at least, the RFC claims that the current growth rate is 2 TB/month so we shouldn't worry about a one-time increase, but neither of those seems accurate | 15:00:51 |
| ElvishJerricco | So how much of a problem is this? Can we absorb a 15-30% hit to cache size growth? Or does that make the RFC a non-starter from an infra perspective? | 15:08:38 |
| emily | the infra team isn't the one paying the bills | 15:09:03 |
 toonn | Wasn't the sponsorship extension based on a commitment to reduce the size of the cache? | 15:14:08 |
| emily | that's my understanding, which I also mentioned in https://github.com/NixOS/rfcs/pull/185#issuecomment-2748339200 | 15:14:33 |
| emily | I just mean that's more Foundation than it is infra team, AFAIU | 15:15:05 |
