[BUG] At regular intervals, connections to MySQL database fail

Bug

A recurring [Warning] Aborted connection appears in the logs.

Containers

services:
 mailman-core:
    image: maxking/mailman-core:0.5
  mailman-web:
    image: maxking/mailman-web:0.5
  database:
    image: mariadb:10.5

Database configured as in:
https://github.com/maxking/docker-mailman/blob/b4390bb0d666e1390dbf2435b553dc5d17c77ae3/docker-compose-mysql.yaml#L50-L61

Logs

From container database

Host 172.24.0.24 is container mailman-core

2024-07-02 12:15:52 10484 [Warning] Aborted connection 10484 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:20:52 10487 [Warning] Aborted connection 10487 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:25:52 10494 [Warning] Aborted connection 10494 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:30:53 10497 [Warning] Aborted connection 10497 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:35:53 10504 [Warning] Aborted connection 10504 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:40:53 10508 [Warning] Aborted connection 10508 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:45:55 10512 [Warning] Aborted connection 10512 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:50:54 10517 [Warning] Aborted connection 10517 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 12:55:55 10522 [Warning] Aborted connection 10522 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:00:55 10526 [Warning] Aborted connection 10526 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:05:56 10532 [Warning] Aborted connection 10532 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:10:56 10537 [Warning] Aborted connection 10537 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:15:57 10542 [Warning] Aborted connection 10542 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:20:58 10547 [Warning] Aborted connection 10547 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:25:57 10553 [Warning] Aborted connection 10553 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:30:58 10556 [Warning] Aborted connection 10556 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:35:58 10563 [Warning] Aborted connection 10563 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:40:59 10567 [Warning] Aborted connection 10567 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)
2024-07-02 13:46:01 10571 [Warning] Aborted connection 10571 to db: 'mailman' user: 'mailman' host: '172.24.0.24' (Got an error reading communication packets)

It strikes me that the warning appears at 5 minute intervals (+- few seconds), with no such line created by interacting with Postorius or Hyperkitty.

Is there a cron job configured in mailman-core at a 5 minute interval?

Begin with docker-compose-mysql.yaml lines 50-61 and the mailman-core container configuration; compare the five-minute database log pattern with activity from Postorius and Hyperkitty. Done means determining whether mailman-core has a five-minute cron job and identifying the cause of the aborted MariaDB connections.