From 3c2ffe2b4214619dd999800b03b808acea86e666 Mon Sep 17 00:00:00 2001
From: MrAlders0n <55921894+MrAlders0n@users.noreply.github.com>
Date: Wed, 21 Oct 2026 15:59:53 -0400
Subject: [PATCH] Upgrading to 2.1: timings measured on a large deployment
 (#42)

---
 docs/upgrading.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/docs/upgrading.md b/docs/upgrading.md
index 5387e1b..1b2ec52 100644
--- a/docs/upgrading.md
+++ b/docs/upgrading.md
@@ -195,6 +195,23 @@ docker compose up -d
 A slow disk stretches every phase: on a test server with a rotational disk and about 6 million
 observations, the migrations took 8 minutes and the fills at `duty: 0.25` about an hour.
 
+**Measured on a large deployment** (8 vCPU, 8 GB RAM, NVMe; 91 GB database with 35 million
+routes, 30 million observations and 3 million packets; default pacing):
+
+| Step | Time |
+|---|---|
+| Pre-building the eight indexes, old version still serving | 1 min 50 s (route hop index 72 s, adverts index 16 s, the rest under 8 s each) |
+| Migrations `004` to `053` at startup | 7.4 s (the two `packets` checks 3.7 s and 1.8 s) |
+| API and ingest down | about 15 s |
+| Channel message pages by site back | 8 min after startup |
+| Observer advert pages | at once (no untyped observations) |
+| Region packet pages back | 50 min after startup |
+| Database size | 91 GB before, 71 GB after |
+
+The region packet fill walks the whole observation id range, newest to oldest, so a database that
+still holds a few very old observations fills for longer than its row count suggests, and the
+`eta` in its progress lines overstates the time left.
+
 Watch the log for these lines; each one ends a phase:
 
 - `Beacon listening on :8080`: migrations done, API up.