Thanks for that feedback Jordan, that's potentially really useful. So maybe you are proposing that something like this is happening:
- I enqueue a massive amount of tasks very quickly (and those tasks enqueue more tasks etc). - Inevitably, there is less capacity available (instances) than necessary. So some tasks get *individually* delayed (they fail to be handled, and go into exponential backoff). - AppEngine keeps spinning up instances until the contention goes away - But, some tasks may have failed to be scheduled enough times in the interim that they now appear "stuck" for a little while. What's actually going on is that they've been "backed off", and have a timestamp in the future when they will try to run. So, it'll look like some tasks are getting stuck. Is that right? Further, and crucially to me, is this invisible via the console? ie: would these tasks be sitting there and not running, but I can't see any evidence of why? I'm asking this because this isn't, for instance, affecting the task's ETA (it might say something like "8 mins ago"). On 16 June 2017 at 06:21, 'Jordan (Cloud Platform Support)' via Google App Engine <google-appengine@googlegroups.com> wrote: > The limits on Task Queue calls can be found on the Quota page > <https://cloud.google.com/appengine/quotas#Task_Queue>, specifically the > 'Queue execution rate' being of importance. > > Too many tasks being executed on a single queue will inevitably result in > underlying contention. This leads to the slow down of task execution (aka > exponential-backoff retry) while tasks wait for resources to handle them. > It is recommended to instead shard your tasks across multiple queues to get > around this limit. You can also tweak your queue.yaml > <https://cloud.google.com/appengine/docs/standard/python/config/queueref> > *'max_concurrent_requests'* setting to prevent any single queue from > hitting this limit. > > Additionally, it is always good to check your logs to ensure that you > didn't see any errors during the gap, as you could be hitting other quotas > limits (which would require time to refill). > > -- > 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/308b61be-732f-4b05-8fe2- > 925ac46c0874%40googlegroups.com > <https://groups.google.com/d/msgid/google-appengine/308b61be-732f-4b05-8fe2-925ac46c0874%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Emlyn https://medium.com/the-infinite-machine - A publication about Google App Engine sutllang.com - My language sUTL https://plus.google.com/u/0/100281903174934656260 - Google+ -- 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/CAMp1VPBojegLPJqbXSKrCPcf9Ma5u1rtAxPko%3DC_17_Se2f_vQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
