Google: Received multi-get response without ETag

[hobbes]

Hi,
thanks to the instructions here, I have been able to configure a calendar from my “other calendars” list.
The url to use is “https://www.google.com/calendar/dav/calendarid@group.calendar.google.com/events/”, where calendarid is found in the Calendar Settings on google.
It seems to work fine, my events are synced, but I receive regular notifications of «HTTP Server error - Received multi-get response without ETag». I can dismiss the notification, but I don’t know the effects it has on my events. And anyway it comes back regularly, I guess at the next sync attempt.
Has anyone encountered that problem ? What can I do to help diagnose it ?

[hobbes]

Here is a logcat of the error.
Before the error itself, I have quite a bunch of these:

11-05 14:06:02.397 18312 3538 I davdroid: [syncadapter.SyncManager] somerandomid@google.com.ics has not been changed on server (ETag still 63676925108)
11-05 14:06:02.403 4585 2844 W ContentResolver: Failed to get type for: content://com.android.calendar (Unknown URL content://com.android.calendar)

then the error itself:

11-05 14:06:02.473 18312 3931 I davdroid: [syncadapter.CalendarSyncManager] Downloading 2 iCalendars: [https://www.google.com/calendar/dav/mycalendarid%40group.calendar.google.com/events/someunknownid_R20181020T092000%40google.com.ics, https://www.google.com/calendar/dav/mycalendarid%40group.calendar.google.com/events/someunknownid%40google.com.ics]
11-05 14:06:03.104 18312 3198 E davdroid: [syncadapter.SyncManager] HTTP/DAV exception
11-05 14:06:03.104 18312 3198 E davdroid: EXCEPTION at.bitfire.dav4android.exception.DavException: Received multi-get response without ETag
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2$1$1.invoke(CalendarSyncManager.kt:135)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2$1$1.invoke(CalendarSyncManager.kt:42)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.SyncManager.useRemote(SyncManager.kt:785)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2$1.invoke(CalendarSyncManager.kt:133)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2$1.invoke(CalendarSyncManager.kt:42)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.dav4android.Response$Companion.parse(Response.kt:211)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.dav4android.DavResource$processMultiStatus$2.invoke(DavResource.kt:384)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.dav4android.DavResource.processMultiStatus(DavResource.kt:403)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.dav4android.DavResource.processMultiStatus(DavResource.kt:354)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.dav4android.DavCalendar.multiget(DavCalendar.kt:150)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2.invoke(CalendarSyncManager.kt:132)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager$downloadRemote$2.invoke(CalendarSyncManager.kt:42)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.SyncManager.useRemote(SyncManager.kt:774)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.SyncManager.useRemoteCollection(SyncManager.kt:795)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.CalendarSyncManager.downloadRemote(CalendarSyncManager.kt:131)
11-05 14:06:03.104 18312 3198 E davdroid: at at.bitfire.davdroid.syncadapter.SyncManager$syncRemote$1$1.run(SyncManager.kt:438)
11-05 14:06:03.104 18312 3198 E davdroid: at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:457)
11-05 14:06:03.104 18312 3198 E davdroid: at java.util.concurrent.FutureTask.run(FutureTask.java:266)
11-05 14:06:03.104 18312 3198 E davdroid: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
11-05 14:06:03.104 18312 3198 E davdroid: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
11-05 14:06:03.104 18312 3198 E davdroid: at java.lang.Thread.run(Thread.java:764)
11-05 14:06:03.133 18312 3198 I davdroid: [syncadapter.CalendarsSyncAdapterService] Calendar sync complete

hth

[hobbes]

oh and a few related lines after that:

11-05 14:06:03.137 18312 3198 I davdroid: [syncadapter.SyncAdapterService] Sync for (com.android.calendar, Account {name=myusername@gmail.com, type=bitfire.at.davdroid}) finished

11-05 14:06:03.201 2293 2415 D SyncManager: failed sync operation JobId=102140 myusername@gmail.com/bitfire.at.davdroid u0 [com.android.calendar] USER ExpectedIn=-4s EXPEDITED Reason=10084, SyncResult: stats [ numParseExceptions: 1]
11-05 14:06:03.202 2293 2415 D SyncManager: not retrying sync operation because the error is a hard error: JobId=102140 myusername@gmail.com/bitfire.at.davdroid u0 [com.android.calendar] USER ExpectedIn=-4s EXPEDITED Reason=10084

[rfc2822]

@hobbes said in caldav sync with google doesnt work anymore:

11-05 14:06:02.473 18312 3931 I davdroid: [syncadapter.CalendarSyncManager] Downloading 2 iCalendars: [https://www.google.com/calendar/dav/mycalendarid%40group.calendar.google.com/events/someunknownid_R20181020T092000%40google.com.ics, https://www.google.com/calendar/dav/mycalendarid%40group.calendar.google.com/events/someunknownid%40google.com.ics]
11-05 14:06:03.104 18312 3198 E davdroid: [syncadapter.SyncManager] HTTP/DAV exception
11-05 14:06:03.104 18312 3198 E davdroid: EXCEPTION at.bitfire.dav4android.exception.DavException: Received multi-get response without ETag

Looks like the server is sending invalid responses…

[hobbes]

but except for the periodic notification, everything seems to work fine… what can I do to help diagnose this ?

[rfc2822]

@hobbes Can you post the HTTP request before the exception? There should be a multistatus response without an ETag response, which would be a server problem.

[hobbes]

Hi, where do I get those requests ? I don’t see any detail in the logat, so I’m not sure what you’re asking for… The only thing that seems weird is this line:

11-07 20:30:15.637  6555  5080 I davdroid: [syncadapter.SyncManager] 1pt1mrnrhtn5o5ai8g832eh323@google.com.ics has been added remotely

It comes back every single time that I sync the calendar.

Other than that, I have a bunch of those:

11-07 20:25:19.596  6476  3803 W ContentResolver: Failed to get type for: content://com.android.calendar (Unknown URL content://com.android.calendar)

But I don’t think that they are related to my notification…

[rfc2822]

@hobbes How did you get the logs? Did you enable external logging in DAVdroid and then transfer the files to your PC?

[hobbes]

I previously used a logcat, but now I found the option to get the comple1pt1mrnrhtn5o5ai8g832eh323te logs from davdroid, with far more information
Apparently there is one event which was added remotely, but when davdroid tries to download it, it gets a 404 error.
It would probably help if I transmited the complete log, but before I do so, does it contain any sensitive information ?

[rfc2822]

@hobbes said in caldav sync with google doesnt work anymore:

It would probably help if I transmited the complete log, but before I do so, does it contain any sensitive information ?

I don’t know. If you want, you can send it to play@bitfire.at (PGP key) and it will of course be treated as confidential.

[hobbes]

ok log sent.
Thanks

[rfc2822]

Thanks for the logs. I was finally able to reproduce a similar situation:

1. Upload an event with UID:a%40b (note the %, for instance coming from some erroneously double-encoded old UID; nevertheless valid) to Google /events/a%40b.ics (or anything else)
2. Google usually rewrites the path (= moves the event) to <UID>.ics, which would be a%40b.ics.
3. However, Google CalDAV REPORT calendar-query reports /events/a%2540b.ics as the URL of the resource.
4. If you want to download /events/a%2540b.ics from Google, it returns 404, although it had just listed this path.

So, in my opinion and what I currently know about it, this seems to be a server problem. It should go away if you delete all events on the server and then only create/sync “clean” events with “good UIDs”. Maybe you can also create a new calendar for testing and see whether this one works?