Suggestions for reducing upload and download times

[saraadams]

Problem

When using remote execution, upload and download times may slow down invocations.

Suggested solution

• DataProvider: extract upload and download times
• SuggestionProvider: reduce upload and download times
  • reduce upload times using --nolegacy_important_outputs (smaller BEP stream)
  • reduce download times using --remote_download_minimal
    • could look at download times in critical path only
    • threshold might be 5% of critical path?
    • suggest maximum improvement by reducing critical path to at best critical path minus all download times
  • set --experimental_remote_downloader to use Remote Asset API
    • look for "fetching: [...]" in analysis phase, should take up sufficiently significant time
    • if using remote caching/execution set value to remote cache/execution url
    • if fully local, could highlight that remote caching or execution could help, with this flag also set