From e68ba1ea79af3d12a8d789df870616747581344c Mon Sep 17 00:00:00 2001
From: Alex Anderson <191496+alxndrsn@users.noreply.github.com>
Date: Wed, 15 Jan 2025 18:23:11 +0300
Subject: [PATCH] runSequentially(): expand docs on current usage (#1367)

The "current use" documentation does not cover all current uses.

Alternatively, this documentation could be removed completely, and intention for calling runSequentially() could be defined at the call sites.
---
 lib/util/promise.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/util/promise.js b/lib/util/promise.js
index 75a901155..b32544570 100644
--- a/lib/util/promise.js
+++ b/lib/util/promise.js
@@ -78,8 +78,12 @@ const runSequentially = async (functions) => {
 
   for (const fn of functions) {
     // reason:      we want to run functions sequentially
-    // Current use: each function is dependent on DB transaction
-    //              we can't do parallel processing with transaction
+    // Current uses:
+    // 1. prevent deadlock due to parallel queries starting sub-transactions
+    //    See: #868 / worker.runJobs()
+    // 2. reduce number of parallel database connections compared Promise.all()
+    //    See: #1344 / Analytics.previewMetrics()
+
     // eslint-disable-next-line no-await-in-loop
     results.push(await fn());
   }