Message bus in TYPO3 with the Doctrine DBAL messenger transport

19. Mai 2025TYPO3

The documentation for the message bus can be found on the website https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ApiOverview/MessageBus/Index.html, but there are a few additions that I want to make:

During the development I used the default synchronous transport
```
\Symfony\Component\Messenger\Transport\Sync\SyncTransport
```
When I switched to the asynchronous transport
```
\Symfony\Component\Messenger\Bridge\Doctrine\Transport\DoctrineTransport
```
my code did not work at first. The cause was that I used the DataHandler and therefore must use
```
Bootstrap::initializeBackendAuthentication();
```
together with the backend user _CLI_ for the asynchronous transport but not for the synchronous transport.

Additions to the configuration of the systemd service

In the file of the systemd service
```
/etc/systemd/system/typo3-message-consumer-projectname.service
```
I had to add the environment variable
```
TYPO3_CONTEXT=Development/dsimon
```
The content of the file then looks like this:

[Unit]
Description=Run the TYPO3 message consumer
Requires=mariadb.service
After=mariadb.service

[Service]
Environment="TYPO3_CONTEXT=Development/dsimon"
Type=simple
User=www-data
Group=www-data
ExecStart=/usr/bin/php8.3 /var/www/projectname/vendor/bin/typo3 messenger:consume doctrine --exit-code-on-limit 133
# Generally restart on error
Restart=on-failure
# Restart on exit code 133 (which is returned by the command when limits are reached)
RestartForceExitStatus=133
# ..but do not interpret exit code 133 as an error (as it's just a restart request)
SuccessExitStatus=133

[Install]
WantedBy=multi-user.target

After making changes to this file, the command
```
systemctl daemon-reload
```
must be executed
The service can be started and stopped with

systemctl start typo3-message-consumer-projectname.service
systemctl stop typo3-message-consumer-projectname.service
systemctl restart typo3-message-consumer-projectname.service

With the command
```
systemctl status typo3-message-consumer-projectname.service
```
you can check whether the service is running and with the command
```
journalctl -u typo3-message-consumer-projectname.service -n 10
```
you can check for error messages when the service is not working.
If you make changes to your TYPO3 code the systemd service must be restarted. Otherwise it executes the old code.