The best way to investigate the latency of your own application is to directly apply logging <https://cloud.google.com/logging/docs/setup/java#app_engine> throughout your code. Log the timestamps of when your application receives a request, before and after it performs any logic, before and after using the Google Cloud Client Libraries (and all other API requests), and before it returns. This way you can exactly pin-point what in your code is causing the latency.
You can check your App Engine Dashboard <https://console.cloud.google.com/appengine/>to confirm that the latency is not mainly caused by instance startup time (as seen in the "Loading latency" graph), but is simply latency caused by your code (as seen in the "Latency" graph). One major cause could be your excessive memory usage. You are using F1 class instances <https://cloud.google.com/appengine/docs/standard/#instance_classes> which have 128 MB of virtual memory, but you are constantly exceeding that and averaging around 215 MB (as seen in the "Memory Usage" graph). This could lead to App Engine shutting down an instance after finishing a request, forcing new incoming requests to be loaded for the first time on new instances. Of course this is only to help reduce the latency of App Engine. The latency you see from your Android device is caused by a much larger number of things like networking paths and connectivity. If you wish to investigate the latency of the Android Client library, you must instead eliminate any networking latency and run the library on a machine that has tested fast connection to Google (like the Cloud Shell) <https://cloud.google.com/shell/>. If you do end up finding that the latency is truly due to the Client Libraries (and not your network or App Engine application code), then you can directly report your findings to the appropriate library engineering team in their Github Issue Tracker. <https://cloud.google.com/apis/docs/cloud-client-libraries> - Note that Google Groups is reserved for general product discussions and is not for technical support. If you require further support for reducing the latency of your application it is recommended to post your detailed questions <https://stackoverflow.com/help/how-to-ask> to Stack Exchange <https://cloud.google.com/support/docs/stackexchange> using the supported Cloud tags. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/28aaeb4a-eef0-499b-9194-956a4aee438e%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
