this may be a crazy question - I want to host an algo-trading system which will trigger morning 9.00 AM and runs till 3.00 PM. I'm considering hosting either as a service using systemd or using gitlab cicd to trigger this. (i can watch activity here at any moment).
what is the best choice? is cicd reliable for running the whole day ?
I know your bounty is saying you're looking for a canonical answer, but I don't think such an answer really exists for this question since there is no real right answer based on your use-case.
You can absolutely create a CI/CD job and set the timeout to 6 hours, however I don't think that's really what you want to do here. It sounds like you essentially just want a background job that kicks off every day and processes your trades. You may also want notification if something in the job fails, or you may want it to restart the job automatically.
Systemd would be the simplest way to do this, and KISS is always a good principle to follow when designing your solution. Using GitLab would require you to host the GitLab service itself, along with a runner that would execute the jobs each day, whereas Systemd would only require you to register the service.
If you scale up to the point where you're trying to run many such jobs at once, you'll still likely be better off with a workflow manager such as Apache Airflow (or AWS step functions, etc).
So overall, I wouldn't recommend a CI/CD solution to run what is effectively a job server. Start with Systemd while you're small, then migrate to a true workflow solution when you need to scale.
