I have recently implemented the Google Analytics iOS SDK v2 into a number of iOS apps, and I have noticed that there are some seemingly large discrepancies in the reporting that is now being generated. My main concern is that the total event count for my tracking ID is about 50% lower than what my internal metrics suggest it should be. I have spent some time trying to weed out possible issues.
First I thought I might not have been making the tracking calls to Google from within the app, but those all checked out. Next I tested the theory that the metrics weren't making it from the local database out over the network. After setting up wireshark to monitor the network traffic though, this too seemed to be working properly. Next I tried processing the events more slowly as I thought that it might have been the fact that events are fired in short time intervals that might be the problem. After slowing the event fire rate to at most 1 per second and then further to at most 1 per 3 seconds, I was still seeing a roughly 50% event loss when monitoring my test sessions in the web UI. Also, it seemed somewhat random which events would be dropped in the reports that I generated.
Here is some other info about my analytics configuration:
- Dispatch interval of 60s
- Manually starting sessions
- Using multiple trackers
Strangely, the android versions of the same apps are not exhibiting the same issue.
If anyone has had similar experience or has any suggestions they would be greatly appreciated.
After reaching out to the Google Analytics team, they confirmed that betas 3 and 4 of the iOS SDKs have a bug that is responsible for the underreporting that I'm seeing.
On https://developers.google.com/analytics/devguides/collection/ios/v2/events there is info ( typo, Android -> Analitics):
Note: The Google Android SDK for iOS may throttle events, as well as other hits, if a large number of send calls are made in a short period of time.
So, i think that Your problem can be related with this. If You're monitoring traffic by wireshark and Your app is sending proper calls, i think there is not much that You can do. Maybe, try to increase interval between calls to really undisputed value - like 30 seconds - and then count the difference.
来源：https://stackoverflow.com/questions/14248241/events-lost-when-using-google-analytics-for-ios-sdk-2-0b3