Right now to get stats for a puma process the only way is to go through the control server. The puma-stats-logger does this by reading in a state file then querying the control server manually.
7ad7798e9d/lib/puma_stats_logger/middleware.rb (L28)
Instead, I’m proposing adding a top level `Puma.stats` method that will allow anyone inside of the same process to get access to the stats.
This could be instrumented by a gem to theoretically export these stats to say a Heroku dashboard where we could list out backlog or thread count.
The format of stats is a hash, and will change depending on if the server is in “single” or “clustered” mode.
Clustered:
```
{ "workers": 2, "phase": 0, "booted_workers": 2, "old_workers": 0, "worker_status": [{ "pid": 19832, "index": 0, "phase": 0, "booted": true, "last_checkin": "2018-03-12T16:03:12Z", "last_status": { "backlog":0, "running":5 } },{ "pid": 19833, "index": 1, "phase": 0, "booted": true, "last_checkin": "2018-03-12T16:03:12Z", "last_status": { "backlog":0, "running":5 } }] }
```
Single:
```
{ "backlog": 0, "running": 2 }
```
Alternatively if we could somehow enable another process to get these stats from Puma via pumactl by default without requiring any additional in app config, that would also work.