Instrument GitLab Shell and log metrics data to a file
We need to start instrumenting the code so we know where time is being spent. The easiest way is to essentially measure blocks (with a name) and log the metrics to a file. This allows us to scrape the data using mtail (as discussed in https://gitlab.com/gitlab-com/infrastructure/issues/502).
Data to measure:
- CPU time used
- Real time used
- call count
See the GitLab CE code for more information on how this is currently done.