perfect ... thanks ... On Feb 21, 10:56 am, Robert Kluin <[email protected]> wrote: > Why not leave the rate at 1/s, but set max_concurrent_requests to 1 as > Nick suggested? > > > > > > > > On Tue, Feb 21, 2012 at 12:56, James Gilliam <[email protected]> wrote: > > Yes ... I saw the 5 per sec in the admin ... > > > Also, I just realized why I think gae created so many instances when i > > had the queue at 1/s ... I had assumed the tasks would take much less > > than a second (which was true at the beginning); but as the number of > > entity writes continued, the latency for the writes got larger and > > eventually took longer than a second ... at which point gae started > > new instances to keep up with the 1 sec rate ... i had assumed it > > would not consider starting a new task until the previous one in the > > queue finished -- this appears to not be the semantics > > > My solution is to slow down the tasks even further ... to say 15 / > > min ... so that new instances will not be created ... > > > On Feb 19, 12:21 pm, Nicholas Verne <[email protected]> wrote: > >> James, > > >> The misreporting of number of tasks in a queue is a known bug that > >> we're working on. It causes undue alarm for our users. > > >> How do you know that GAE changed the target rate to 5 / sec ? Did you > >> observe this in the admin console? > > >> The queue's rate is the rate at which tasks are dispatched to your > >> app. If your queue is set to run 1 / sec and your task latency is > >> longer than 1 second, you should expect to have more instances spin > >> up. > > >> If you wish to prevent more than one task running at a time, set your > >> queue's max_concurrent_requests to 1. > > >> Nick Verne > > >> On Mon, Feb 20, 2012 at 3:35 AM, James Gilliam <[email protected]> > >> wrote: > >> > I am using task queue in python. > > >> > I added 10,000 tasks for a queue set to run at 1/sec and a bucket of > >> > 1 ... they were short tasks and I didn't want them to run > >> > immediately ... I didn't even want them to run multiples per second > >> > even though the latency was low ... it was ok if it took hours as I > >> > knew it would at 1/sec. I figured it would create a second instance > >> > as the site was continuing to run ... but I was pretty surprised with > >> > what actually happen. > > >> > At first the queue started processing fine ... approx 60 tasks running > >> > per minute ... > > >> > Then GAE decided to run them at a faster rate, change the target rate > >> > to 5 / sec and created lots of new instances ... > > >> > When there were about 3000 tasks left ... GAE went crazy and said > >> > there were nearly 200,000 tasks in the queue ... > > >> > As far as I could tell, the number of tasks being reported was just an > >> > anomaly ... but it was alarming given that GAE was creating instances > >> > like crazy. > > >> > The tasks would add new records (sometimes) and I noticed that the > >> > latency of these tasks increased the longer the tasks ran. At first > >> > just 200ms ... by the end nearly 1400 ms. > > >> > So -- > > >> > 1. The most important question -- Why did GAE not respect my desire to > >> > run the queue at 1 / sec ? Is there a way I can stop GAE from > >> > overriding my wishes? > > >> > 2. Was the latency increasing because the records being added were > >> > slowing new records from being added? > > >> > 3. The invalid number of tasks seems like a harmless bug since new > >> > phantom tasks were not actually created (as far as I know). > > >> > -- > >> > 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 > >> > athttp://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 > > athttp://groups.google.com/group/google-appengine?hl=en.
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