From 1a48d51e5bc2957bd72ab29cb8ed141777c98257 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Tue, 3 Aug 2021 17:14:06 -0400 Subject: [PATCH] devblog --- ...ay_640__finally_dealt_with_clock_skew.mdwn | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 doc/devblog/day_640__finally_dealt_with_clock_skew.mdwn diff --git a/doc/devblog/day_640__finally_dealt_with_clock_skew.mdwn b/doc/devblog/day_640__finally_dealt_with_clock_skew.mdwn new file mode 100644 index 0000000000..363ceb9af0 --- /dev/null +++ b/doc/devblog/day_640__finally_dealt_with_clock_skew.mdwn @@ -0,0 +1,20 @@ +I've been unsatisfied with git-annex's handling of clock skew since day 1. +Since it relies on timestamps, it needs clocks to be synchronised across +users, at least to a reasonable extent. A clock in the far future or distant +past could potentially confuse git-annex a lot. Vector clocks felt like +the right kind of solution, but also wrong somehow. + +I've finally cracked it! See [[todo/git-annex_branch_clocks]] for the +details, but in summary, git-annex will be able to detect clock skew +and fall back to vector clocks, but will otherwise continue to use +timestamps for their benefits over vector clocks +(ie, having some idea about what order disconnected events actually occurred, +to the extent physics makes that possible). + +That is mostly implemented, only needs some more testing and cleanup before +merging. + +---- + +Today's work was sponsored by Graham Spencer +[on Patreon](https://patreon.com/joeyh)