Since update to 5.5.0: significantly increased network traffic between Matomo web server and DB server (Archiving?)

Support & Bugs
1

After updating to Matomo 5.5.0, we’re seeing a clearly higher and very steady amount of network traffic between our Matomo HTTP/web server and the separate DB server. Before the update, traffic was much lower; since then it stays consistently higher almost 24/7 with a saw-tooth pattern (periodic peaks - archiving cron).
Functionally everything works (UI/reports are fine), but it looks like something in the background is doing much more work than before (e.g., archiving / re-archiving / invalidations).

SNMP graphs (web and DB interfaces) show the jump very clearly:

grafik
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Questions for the community

  1. Is this behavior since 5.5.0 known (e.g., more invalidations or changed archiving behavior)?

  2. Are there recommended settings or workarounds to bring DB load/traffic back to normal?

  3. Which metrics/logs are most helpful to pinpoint the cause?

Environment

  • Matomo: 5.5.1

  • Setup: Dedicated web and DB servers; traffic increase starts exactly at the update time

  • Database: 11.4.5-MariaDB

  • PHP: PHP 8.3.19

  • Cron/Archiving: console core:archive via cron - 1 hour

  • Browser archiving: disabled

Symptoms (short)

  • Clear step-increase of bandwidth starting at the update

  • Saw-tooth pattern (archiving cron)

  • No visible errors in the UI, but continuously high web↔DB communication

Checks done so far

  • System load on web/DB OK (CPU/IO fine), but network remains high

  • Looked over Matomo logs/cron output — no obvious errors (details can be provided)

  • No intentional new segments/reports enabled

Attachments

  • SNMP traffic screenshots (web & DB interfaces) showing the step change

Config & diagnostics (for reference)

Cron line:

/usr/bin/php /var/www/piwik/console core:archive --url=https://server.tld/ > /var/log/piwik.cron.log

Diagnostic commands:

-- Check size/backlog of invalidations:
SELECT COUNT(*) AS invalidations FROM matomo_archive_invalidations;
--> 3

What I’m looking for
Pointers on whether 5.5.0 introduced changes/regressions that increase DB traffic (e.g., different invalidation strategy, segment reprocessing, etc.), plus best practices/settings to bring it back to normal.

Thanks a lot!

Best from Tyrol
Andy