Make log level configurable

[x4e-jonas]

By default, CottontailDB runs in DEBUG mode. This is nut suitable for production deployments.

The log level should be runtime configurable (either by argument, option in config file or environment variable) and it might be a good idea to consider and document a sane default value.

[ppanopticon]

In the next major release, it will be possible possible to provide a custom log4j2.xml via program configuration.

[x4e-jonas]

That's great, though it's more convenient if you're able to define the log lever rather than deploying a whole XML config file yourself.

[x4e-jonas]

A very simple implementation is shown here: vitrivr/cineast#378

[ppanopticon]

While this may very well be ideal in your case, I still prefer the specification of the configuration file.

There is much more to logging than just the log level (e.g., logging to file vs. logging to console, log rotation etc.). Being able to specify your own log4j2.xml enables you to fine-tune these aspect to your particular use-case and setup.