Since usage stats are recorded from the dashboard (which will become API server), it is not collected when the dashboard is not included (include_dashboard=False).
This PR fixes the issues by
change dashboard -> API server (to avoid confusing users that dashboard is still started when include_dashboard=False)
Only load modules that are irrelevant to the dashboard from the API server, so it will have the same impact as no dashboard.
Show usage stats prompt when it's enabled.
Current UX are:
* The usage stats enabled or disabled message is shown every time in both terminal and dashboard.
* If users don't explicitly enable or disable usage stats, the first time they start a ray cluster interactively, they will be asked to confirm and will enable if no user action within 10s. If it's non-interactive, collection is enabled by default without confirmation.
* ray.init() doesn't collect usage stats
* Usage stats can be disabled via three approaches: 1. RAY_USAGE_STATS_ENABLED env var, 2. ray xxx --disable-usage-stats, 3. ray disable-usage-stats
Fix bug from the previous fixes.
Add more tests
Stop using m5.xlarge (not supported now)
There are 2 hard blockers from the infra: 1. Large size disk is not supported. 2. m5.xlarge is not supported. Both are considered as a high priority to be fixed soon.
This is the second PR to implement usage stats on Ray. Please refer to the file usage_lib.py for more details.
The full specification is here https://docs.google.com/document/d/1ZT-l9YbGHh-iWRUC91jS-ssQ5Qe2UQ43Lsoc1edCalc/edit#heading=h.17dss3b9evbj.
This adds a dashboard module to enable usage stats. **Usage stats report is turned off by default** after this PR. We can control the report (enablement, report period, and URL. Note that URL is strictly for testing) using the env variable.
## NOTE
This requires us to add `requests` to the default library. `requests` must be okay to be included because
1. it is extremely lightweight. It is implemented only with built-in libs.
2. It is really stable. The project basically claims they are "deprecated", meaning no new features will be added there.
cc @edoakes @richardliaw for the approval
For the HTTP request, I was alternatively considered httpx, but it was not as lightweight as `requests`. So I decided to implement async requests using the thread pool.
