quick assessment of chrony's accuracy
https://kwynn.com/t/21/10/chm/ - live
My purpose is to add details to my accurate clock widget:
https://kwynn.com/t/9/12/sync/ https://github.com/kwynncom/javascript-synchronized-clock
I have found that Chrony's own assessment of accuracy, which is all that is displayed now, is not useful in itself. I plan to add details to that widget that give a far more complete assessment.
INSTALLATION / REQUIREMENTS
This needs my nanotime PHP extension: https://github.com/kwynncom/nano-php-extension And parts of my nanoseond web server: https://github.com/kwynncom/web-timeserver-nanosecond-precision It's expecting chronyParsed.php from that project in a specific path relationship, in this project's main.php Needs read permission for the files in /var/log/chrony Needs sntp from https://github.com/kwynncom/sntp-client in the PATH (see that project's README for installation notes)
IMPLEMENTATION NOTES
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/var/log/chrony does not necessarily have world-read and passthrough (directory) permission. I changed that where needed. I don't see any harm in it, although perhaps I'm missing something. I should say I don't see any harm given that I'm already publishing this information.
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Log rotation can cause /var/log/chrony/measurements.log and the other 2 to not exist for a time. I tried to turn logration off for chrony. I'll see how that works in about 23 hours.
OTHER NOTES
Getting the sign right per RFC 4330 page 13 - https://datatracker.ietf.org/doc/html/rfc4330 : $t = ((($T[1] - $T[0]) + ($T[2] - $T[3]))) >> 1;
HISTORY
I took the first files from: https://github.com/kwynncom/web-timeserver-nanosecond-precision