diff -Nru update-notifier-3.192.30.8/debian/changelog update-notifier-3.192.30.9/debian/changelog
--- update-notifier-3.192.30.8/debian/changelog	2021-05-14 20:02:18.000000000 +0100
+++ update-notifier-3.192.30.9/debian/changelog	2021-08-05 15:01:11.000000000 +0100
@@ -1,3 +1,11 @@
+update-notifier (3.192.30.9) focal; urgency=medium
+
+  * Sleep for up to an hour in the background in order to spread the load
+    of checking for release updates on the Ubuntu infrastructure
+    (LP: #1836475)
+
+ -- Dave Jones <dave.jones@canonical.com>  Thu, 05 Aug 2021 15:01:11 +0100
+
 update-notifier (3.192.30.8) focal; urgency=medium
 
   * debian/control: add lsb-release to the update-notifier-common depends as
diff -Nru update-notifier-3.192.30.8/debian/update-notifier-common.cron.weekly update-notifier-3.192.30.9/debian/update-notifier-common.cron.weekly
--- update-notifier-3.192.30.8/debian/update-notifier-common.cron.weekly	2021-05-14 20:02:18.000000000 +0100
+++ update-notifier-3.192.30.9/debian/update-notifier-common.cron.weekly	2021-08-05 15:00:12.000000000 +0100
@@ -4,5 +4,12 @@
 
 [ -x /usr/lib/ubuntu-release-upgrader/release-upgrade-motd ] || exit 0
 
-# Check to see whether there is a new version of Ubuntu available
-/usr/lib/ubuntu-release-upgrader/release-upgrade-motd
+sleep_then_check() {
+    # Sleep for up to an hour to spread the load of checking for updates on
+    # the Ubuntu infrastructure
+    sleep $(shuf -i 1-3600 -n 1)
+    # Check to see whether there is a new version of Ubuntu available
+    /usr/lib/ubuntu-release-upgrader/release-upgrade-motd
+}
+
+sleep_then_check &