1422672 - Uptick of failures in Firefox 58: bookmarks fails with "Changed item missing GUID"

Status: RESOLVED WORKSFORME

(Firefox :: Sync, defect, P3)

Description

[Mark Hammond [:markh] [:mhammond]]

This is the largest number of bookmark errors in 58 but it doesn't appear in earlier versions (which makes sense as the message only landed in 58 via bug 1405563)

Note that even though it's the largest count of errors, the engine is still performing extremely well in 58, so the raw count is probably quite low - but still worth looking in to.

Comment 1

[Mark Hammond [:markh] [:mhammond]]

Thom to see if this appears to decline as places maint. does its thing.

Comment 2

[Thom Chiovoloni [:tcsc] (ex-moco)]

This seems to impact about 0.1% of users and when it occurs it fixes itself about 30%-50% of the time over a span of a month ( the percentage varied a lot depending on my sample size -- which makes sense given how rare it is).

Comment 3

[Mark Hammond [:markh] [:mhammond]]

I played a little more with this via Jupyter and things are actually looking reasonable here. I looked at every Aurora ping over the last 100 days - https://gist.github.com/mhammond/99b93d92a02c24099f8baa7bccdcc3a1

In summary:

* Only 57 users ever saw this error and 47 of them shows that it recovered.
* Recovery tended to happen after ~ a week, implying places maintenance did indeed fix the issue.
* Of the 10 users who did not recover, only 2 seem to see this error continue and not recover. The others either stopped sending pings less then 7 days after first recording the error (so may have recovered if the profile kept syncing) or had the error start less than a week ago (so hopefully will recover)

So it's a little worrying that we continue to see this error be introduced in profiles that were previously working, but it's heartening that both (a) most users recover and (b) the number of affected users is small.

Given the above, I'm not sure this is actionable...

Comment 4

[Mark Hammond [:markh] [:mhammond]]

s/users/devices/ above...

Comment 5

[Mark Hammond [:markh] [:mhammond]]

https://screenshots.firefox.com/p7Ow3XF4kwDfytsr/nbviewer.jupyter.org shows that 58 is looking good - these errors are dropping significantly, so I think I'll close this as WFM.