_changes stop working in iOS 10

couchbaselabs / Couchbase-Lite-PhoneGap-Plugin

Plugin to install Couchbase Lite in your PhoneGap app on iOS or Android

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_changes stop working in iOS 10 #86

Open pasin opened 7 years ago

pasin commented 7 years ago

The issue originated from https://github.com/couchbase/couchbase-lite-ios/issues/1477.

I believe it's the issue is caused by either the HTTP Client or iOS WebKit. We should do some testing on this.

msanilkumar2020 commented 7 years ago

Any update on this issue?

We are not getting _changes in iOS.

Thanks, Anil Kumar

pasin commented 7 years ago

Sorry, we don't have any update. Can you post exact the _changes request including all parameters that you are using? What is the HTTP client you are using to make _changes request in the application?

Crapulax commented 7 years ago

To provide a bit more information, we workarounded the issue by:

setting a _changes heartbeat* to 20s (20000). Using a timeout of 40s at the http level was also working.
reinitializing the listen when app move from background to foreground Note that resume reinialization was tricky because we had to know if the issue had occured or not. We determine this by keeping last sequence received by _changes and comparing it with update_seq from DB. If they are equal we loop on it in case it is down.

Above is not satisfactory as it requires tricky computations.

*heartbeat: edited (wronly wrote timeout)

pasin commented 7 years ago

I believe a better approach would be adding heartbeat=30000 to the longpoll _changes feed request URL. Another option would be adding timeout to _changes feed request BUT currently couchbase-lite-ios doesn't support _changes feed timeout yet (See https://github.com/couchbase/couchbase-lite-ios/issues/1236).

FYI, we did experience that some HTTP clients do not abort the requests properly after timing out so the requests get stuck and have never returned the result (See https://github.com/couchbase/couchbase-lite-java-core/issues/1296 for more info).

Crapulax commented 7 years ago

Sorry Pasin, I wrongly wrote timeout, we should read heartbeat instead. I update my post accordingly.

I am checking right now if using a promise as timeout can let us remove the tricky stuff on app resume

pasin commented 7 years ago

@Crapulax Thanks for the update.