diff --git a/changelog.d/gsta203-pr3-subshards.md b/changelog.d/gsta203-pr3-subshards.md index 392c53a7c..e4b7df136 100644 --- a/changelog.d/gsta203-pr3-subshards.md +++ b/changelog.d/gsta203-pr3-subshards.md @@ -1 +1 @@ -The Linux free suite now runs on 10 `ubicloud-standard-8` machines, each running its tests as 4 sandboxed sub-shards side by side, instead of 20 `ubicloud-standard-4` machines running one file at a time. In a 3-run A/B at one commit, the slowest shard dropped from 389–450 s to 224–258 s and the cost per run dropped from about $0.39 to $0.32 at Ubicloud premium prices, with the same per-file test counts and no new failures. The CI plan now stores each shard's sub-shard count (`--ci-plan --shard-jobs k`), keeps the exclusive host-state shard at one child, and `--ci-verify` rejects a shard that ran at a different count. Windows stays at one child per shard, because two sub-shards made Windows file-lock cleanup failures show up in two of three runs. Dispatch-only `free_jobs` and `windows_jobs` inputs exist for future experiments. See docs/TESTING_INTERNALS.md#sub-shards-inside-one-ci-job. +The Linux free suite now runs on 10 `ubicloud-standard-8` machines, each running its tests as 4 sandboxed sub-shards side by side, instead of main's 20 `ubicloud-standard-4` machines (set by #3710) running one file at a time. Both use 80 vCPUs per run. In a 3-run A/B at one commit against that main setup, the slowest shard dropped from 389–450 s to 224–258 s and the Ubicloud cost per run dropped from about $0.39 to $0.32 at premium prices, with the same per-file test counts and no new failures. The CI plan now stores each shard's sub-shard count (`--ci-plan --shard-jobs k`), keeps the exclusive host-state shard at one child, and `--ci-verify` rejects a shard that ran at a different count. Windows stays at one child per shard, because two sub-shards made Windows file-lock cleanup failures show up in two of three runs. Dispatch-only `free_jobs` and `windows_jobs` inputs exist for future experiments. See docs/TESTING_INTERNALS.md#sub-shards-inside-one-ci-job.