Unable to synchronize replica

[JakeJacobs]

I have a very perplexing problem.  I have a hosted feature with 6 layers and a related table (just related to one of them). I have a web map that I open in Collector (new version).  I have created multiple offline areas on my iPad (ios 12).

I have no problem creating the caches.  And at first when I start creating data and syncing, everything seems fine. But at some point I start getting an error "Unable to synchronize replica. Sync replica internal error".  This is with no local edits, just bringing down changes from the parent.

If I delete the offline area from the device and create a new one, it creates just fine, but the first time I try to sync, even with no local edits, having done nothing but create the cache, the sync fails.

What's even weirder is that some of the caches continue to sync successfully, and some do not.  Even when they are in the same geographic area (seeming to rule out a data issue).

I am under a tight timeline to deploy this mobile project and am really worried about this behavior.

[BrantCarman]

I'm having similar issues. Download works fine, but when I attempt to sync, I get the "Sync failed" message.  Oddly enough, any local edits that were made appear to be going through and syncing properly, despite the error message.  Would love to here if you've figured this out.

Thanks!

Collector version 19.0.1 and 19.1.0 (iOS) yield the same results.

[ThomasJones1]

Hello Erika,

Have any changes been made to the web map or feature service schema? If web map or schema changes are made while the web map if offline on your mobile device this can cause sync issues. 

Are you logging into Collector via ArcGIS Online or Portal? If you are using Portal I would recommend reviewing the Portal and ArcGIS Server logs at 'DEBUG' level after you attempt to sync.

Collector for ArcGIS 19.1.0 (iOS) does have some in built logging functionality. I would also recommend reviewing the Collector logs after attempting to sync.

1. Launch Collector for ArcGIS and sign in to either ArcGIS Online or ArcGIS Enterprise.
2. On the top left (if using an iOS device), click the user's icon to go to the ProfileTap three times over the top of the name.
3. This should create a developer option at the bottom of the list. Click on developer and enable logging.

Hope this helps!

Thanks,

Thomas

[JakeJacobs]

Thanks for the belated reply Thomas. This is still an issue that our users are experiencing intermittently. The only workaround we have now is to find good wifi and make a new cache before continuing.

No changes have been made to the web map or to the schema.

I am not using Portal.

I have enabled debugging.  The errors look like:

7/8/19, 7:47 AM [73AF54A1-0F1F-4C87-A7A7-3AAA4E258B72] - Table: (Mapsheet_Error_Log) Error: Error Domain=com.esri.arcgis.runtime.services.error Code=500 "Unable to synchronize replica." UserInfo={NSLocalizedFailureReason=Sync replica internal error - d76da92b-e7fb-4cb5-a960-05c216e9cca2., NSURL=https://services3.arcgis.com/WlYQgAChrqj0tuQi/arcgis/rest/services/Leak_Survey_Mobile_Update_Only/FeatureServer/jobs/831f8679-1f49-436b-b9b9-adb3c331db99, responseJSON={
    error =     {
        code = 500;
        details =         (
            "Sync replica internal error - d76da92b-e7fb-4cb5-a960-05c216e9cca2."
        );
        message = "Unable to synchronize replica.";
    };
    lastUpdatedTime = 1562597209630;
    replicaID = "d76da92b-e7fb-4cb5-a960-05c216e9cca2";
    replicaName = "MyReplica_3636";
    status = Failed;
    submissionTime = 1562597205457;
    targetType = client;
}, NSLocalizedDescription=Unable to synchronize replica.}

[ThomasJones1]

Hello Erica, 

Thank you for attaching the error message is 'Mobile_Update_Only' the only feature service used in the Web Map? I can definitely provide some general troubleshooting advise. If you have the option you may want to create a support case to troubleshoot this issue further. With intermittent issues like this it's always important to try and establish a pattern of behavior.  

• Is there any correlation between what network you use (e.g. WiFi, LTE, Internal Network) and the sync failure? 
• Is there any interruption or drop in network connectivity during the sync process?
• Is the behavior restricted to a specific users or devices?
• Is the behavior restricted to a specific web map or hosted feature service?

If the issue is reproducible you may also wanted to test with a different hosted feature service. This may help rule out any data related issues.

Thanks,

Thomas.

[JakeJacobs]

1. No, this isn't the only feature service in the map. There are two other hosted feature services as well as feature services served up from our own ArcGIS Servers through an AGOL proxy.  All of the hosted feature services exhibit the behavior above intermittently, but not at the same time. Some are even read-only in the map and still cause the sync failure.  I have not seen our own services cause the sync failure, but others may have. They don't report the issue much anymore; they just recreate the cache and move on.

2. No correlation with network.  Folks in the field get it on cell data connections, I get it in the office on WIFI, both internal and external.

3. I can't prove I don't have a network interruption, but our WIFI is pretty solid.

4. Behavior doesn't seem to be restricted to particular users or devices

5. Behavior doesn't seem to be restricted to a particular web map or hosted feature service.

When I talked to support they didn't want to deal with it until it was reproducible, so that's a bit of a catch-22. 

[ThomasJones1]

Hello Erika,

Thanks for the update and additional info. As you may have discussed with support it can often be difficult to troubleshoot intermittent issues. Interesting so it sounds like this issue may be focused more on hosted services. In general I tend to see more issues with registered feature services. Mainly because there are more moving parts involved. 

If you do want to troubleshoot further which I understand isn't easy with internment behavior. I would recommend separating the non-hosted and registered service intos separate web maps. This may help isolate the behavior to ArcGIS Online or Enterprise. If the failure occurs again I would also recommend reviewing the ArcGIS Server logs at 'DEBUG' level in combination with the Collector logs. 

If you do have ArcGIS Server logs I would be happy to review those. To really isolate the cause you'd likely need to try and gather network traffic from Collector when the sync fails. Which of course isn't so easy with intermittent behavior. 

If you have any additional questions please let me know.

Thanks,

Thomas.

[BrantCarman]

I want to chime in here, because I have the same problems with multiple users in the field, using Verizon LTE.  I am also able to reproduce the error at the office, using WiFi.  In my previous comment I claimed that the sync appeared to be working, regardless of the error message.  I was wrong; local edits are being synced, but any updates made on other devices are not being synced to the device.  

I use only hosted layers.  I also use hosted View layers heavily.  I'm curious to know if Erika is also using view layers?

[JakeJacobs]

Brant, I'm not using layer views.  Just the hosted feature layer directly in the web map.

[JakeJacobs]

How do I review the arcgis server logs for hosted feature layers?