[FeatureRequest] redirect DB logs to a separate log file

We can redirect http logs to a file in the influxdb.conf
I want to be able to redirect he DB logs also similarly. Currently if it is run as a systemd service, they only go to /var/log/messages.

Justification:
I am hosting the DB on a AWS EC2 machine. In case the EC2 goes down for some reason, I will lose all the logs on the machine.
Instead I want to be able to forward these logs to splunk or any such service continually so that it is available when needed.

Only way I can do this currently is by running journalctl in a cron and then redirecting to splunk. Since it is a cron, there will always be a delay and loss of the most critical part of logs just before shutdown.

Start by reviewing the logging settings in influxdb.conf and how the systemd service handles database logs. Done means database logs can be redirected to a separate file continuously, so they can be forwarded to Splunk or another external service without relying on delayed cron output.

Written by the indexing model from the issue text.