# Improving Logging in GN2

## What Are We Trying To Solve?

We prioritise maintaining user functionality over speed in GN [with time this speed will be improved].  As such we should be pay more attention at not breaking any currently working GN2 functionality.  And when/if we do, trouble-shooting should be easy.  On this front, one way is to stream-line logging in both GN2/GN3 and make it more script friendly - only report when something fails, not to instrument variables - and in so doing make the process of monitoring easier.

## Goals

- Have script-friendly error/info logs.

- Remove noise from GN2.

- Separate logging into different files: error logs, info logs.  Add this somewhere with Flask itself instead of re-directing STDOUT to a file.

### Non-goals

- Logging in GN3.

- Parsing logs to extract goals.

- Getting rid of "gn.db" global object and in so doing removing "MySqlAlchemy" [that we really shouldn't be using].

- Adding log messages to existing functions.

## Actual Design

- Configure logger to separate logs into different files:

  - INFO file - contains initial bootstrap messages and instrumentation we may have to do.

  - ERROR file - contains real errors.

- Have those settings - the different log files - be part of GN2 start-up script.

- For error messages, use the following format for different error messages:

  - "DATABASE: <message>"

  - "REDIS: <message>"

  - "COMPUTATION: <message>"

  - "API: <message>"

  - "MISC: <message>"

- Have time-stamped logs by month. E.g. "genenetwork2-08-2022.error.log" and "genenetwork2-08-2022.info.log".  This way in future, we can actually run an analysis on what breaks often in GN2.

- Get rid of "utility.logger" module and replace it with Flask's or Python's in-built logging.