Hi, We have a mobile application using GAE as application backend. The mobile client communicates with GAE via REST API. The user data is stored on GAE datastore. So far, things are smooth with GAE. In preparation of launch, we tried a mini concurrent load test 100 qps to retrieve data from datastore for 100 users in a second. The results are pretty bad. Each API request can take from 1-4 secs based on user data.
We had a paid billing application. When 100 concurrent requests were issues, we saw >50% failure rate with 503 service errors. We bumped reserve instances to 10 and we still saw high failure rates. We bumped to 30 front end instances and they we had a successful test run. The app is 'threadsafe'. Why would we need 30 instances to support 100 concurrent qps?? We also tried to change pending latency but not much affect on error rate. The servlet request is not memory or CPU intensive.. It reads daa from datastore and returns a json representation of data.. We were expecting to support 100qps with 3-5 instances. Are we missing something? Our goal is to support 1000 qps with reasonable number of front instances. But 30 instances for 100 concurrent qps seems insanely expensive compared to EC2 or any other provider. The distribution of load also is not anywhere close to even distribution on the available instances. Does anyone has similar experiences? Should we move to EC2? The doc link https://developers.google.com/appengine/kb/general#activerequests has some related information. If the requests take > 1s, is GAE not a good candidate for scaling up? Is there a published limit on how many concurrent requests are supported? We will submit the form and see if we get the restrictions(if any) removed. This thread talks about 10 threads limit for java instances. Can anyone from appengine team confirm this? http://groups.google.com/group/google-appengine/browse_thread/thread/6efce99e84a61646/6401778addb115d2?show_docid=6401778addb115d2 Thanks Neeli -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
