Wow, thanks for the feedback. Does anyone here have a negative experience with thread-safe?
I'm asking because we had received some feedback that this resulted in poorer performance. We don't believe this should be the case at all and want to track down if and why this happens. One huge benefit of concurrent requests should be a drastic decrease in "Request was aborted" errors. The reason that error occurs is because a request sits in a pending queue waiting to be served and times out after X seconds, where X is close to 10. When a new request comes in, we try to figure out if it would be faster to spin up a new instance or place it into a pending queue based on a sliding window of recent request pending wait times. Since Java apps tend take on the order of a few seconds to start up, this can cause us to very heavily favor putting requests into pending queues instead of spinning up new instances. With concurrent requests, your instances are far less likely to block on long running requests (say most of your requests make Facebook API calls and the API just happens to be slow at that time), which should result in a higher threshold before causing requests to back up in your pending queue. "Always on" for Java now guarantees a concurrency of 3 * (number of concurrent requests an instance can handle), which is a HUGE win. Ikai Lan Developer Programs Engineer, Google App Engine Blog: http://googleappengine.blogspot.com Twitter: http://twitter.com/app_engine Reddit: http://www.reddit.com/r/appengine On Thu, Apr 7, 2011 at 12:58 AM, Sérgio Lopes <[email protected]> wrote: > I've been using GAE 1.4.3 with <thread-safe> on and AlwaysOn for a few > days. And my conclusion is that it almost solves all Cold Start problems we > were used to. Now I have fewer instances warmups and most of them are > /_ah/warmup request with no user suffering. In my tests, I had instances > lasting more than 40 hours! > > Nice work, AppEngine team! > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
