diff --git a/6-9-2023 Cohort 1 Sync Notes.md b/6-9-2023 Cohort 1 Sync Notes.md new file mode 100644 index 0000000..4f7d1f3 --- /dev/null +++ b/6-9-2023 Cohort 1 Sync Notes.md @@ -0,0 +1,21 @@ +1433h Started +* Code review +* NTP was selected for time synchronization: see https://gogs.gtsplab.com:5432/SVIG/pricer/src/9af1def1d0a6365fe0cdfe639afa681654b38533/fp2_14.py#L261 +* Links to source code files should use the "permalink" button to reference a specific revision, or the line numbers you're referencing will quickly become wrong. +* Windows time infrastructure: https://learn.microsoft.com/en-us/windows-server/networking/windows-time-service/windows-time-service-tools-and-settings?tabs=config +* MacOS time infrastructure: https://keith.github.io/xcode-man-pages/timed.8.html (every 20 minutes) +* Functional vs non-functional requirements (<= 9.1 hours) https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/specialpollinterval-polling-interval-time-service-not-correct +* https://en.wikipedia.org/wiki/Non-functional_requirement +* Filesystems can't express times with finer granularity than 1ms +* Error in terms of time synchronization is expressed in ppm (1 microsecond) or ppb (1 nanosecond) +* Therefore, there's no advantage to synchronizing to less than 1000ppm. +* Windows resync command: +```powershell +Start-Service W32Time +w32tm /resync +``` +* MacOS resync command: TODO @j +* Use `platform.system()` to figure out whether it's Windows or MacOS, and use `subprocess` to run the NTP sync command so the whole computer has accurate time. Make sure to check the return code (0 = success, not zero = failure) +* Although `subprocess` can give you the return code directly, it's helpful to know that it's available in the shell/powershell as `$?` on MacOS/Linux, and `$LASTEXITCODE` in powershell. +* TODO @j figure out how to get systemd running in the container +1515h: Ended