iOS Firebase SDK v4.7.0 – Performance Monitoring issue possibly related to NSURLConnection instrumentation

[Samuel Braff]

Hi there,

After updating one of our iOS apps to v4.7.0 we're now seeing inexplicable network performance across the board. It appears to be affecting all services within the app that make network requests via NSURLConnection. We believe this to be directly associated with this SDK update as one of our other apps (with an otherwise identical codebase) is not displaying this unwanted behavior. We've cut another build of the afflicted app with the Firebase SDK reverted to the prior version, but any insight into this issue would be appreciated. There's not a lot of detail to share except that the responses are either malformed or being received as 4XX when they originated as 2XX.

Thanks in advance for any commentary on this issue.

Sincerely,

Sam Braff

[Samuel Braff]

Update: after disabling Firebase Performance Monitoring this issue no longer occurs. We will not be able to upgrade to SDK v4.7.0 until this is resolved.

[Eric Shieh]

Hi Sam,

We've identified the issue and have a fix but it may not have made the cutoff for our next immediate release. 

We're making offerings to the release gods now and will let you know when a fix does make it out.

Regards,

Eric

[Samuel Braff]

Thanks for the update, Eric, and the prompt fix. I'll keep an eye out for your update when it ships.

[Eric Shieh]

4.8.0 of Firebase iOS SDK is now available which fixes this issue.