Not sure what you mean by two queues - you mean two queues per invoker? Or 
total?

> On Oct 4, 2017, at 5:14 PM, Rodric Rabbah <[email protected]> wrote:
> 
> A two queue (topic) approach can mitigate the lack of random access from a 
> Kafka topic/queue once a request is committed (in today’s architecture). This 
> could enable work stealing in particular since the (overflow) queue can be 
> drained upstream (ie load balancer) and reassigned to free invokers. 
> Balancing cold start that container locality would them be a heuristic we can 
> apply more judiciously as capacity is available (versus the current approach 
> which binds too early and prevents rebalancing). 
> 
> -r
> 
>> On Oct 4, 2017, at 7:45 PM, Tyson Norris <[email protected]> wrote:
>> 
>> Hi -
>> I’ve been discussing a bit with a few about optimizing the queueing that 
>> goes on ahead of invokers so that things behave more simply and predictable.
>> 
>> In short: Instead of scheduling activations to an invoker on receipt, do the 
>> following:
>> - execute the activation "immediately" if capacity is available
>> - provide a single overflow topic for activations that cannot execute 
>> “immediately"
>> - schedule from the overflow topic when capacity is available
>> 
>> (BTW “Immediately” means: still queued via existing invoker topics, but ONLY 
>> gets queued there in the case that the invoker is not fully loaded, and 
>> therefore should execute it “very soon")
>> 
>> Later: it would also be good to provide more container state data from 
>> invoker to controller, to get better scheduling options - e.g. if some 
>> invokers can handle running more containers than other invokers, that info 
>> can be used to avoid over/under-loading the invokers (currently we assume 
>> each invoker can handle 16 activations, I think)
>> 
>> I put a wiki page proposal here: 
>> https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcwiki.apache.org%2Fconfluence%2Fdisplay%2FOPENWHISK%2FInvoker%2BActivation%2BQueueing%2BChange&data=02%7C01%7C%7C3ff41b0527be4e13398c08d50b8614ee%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C0%7C636427592860490625&sdata=afOAkeXRW6iArXa72IGd6gnhVyrOwXsDxnjfSAQqL18%3D&reserved=0
>> 
>> WDYT?
>> 
>> Thanks
>> Tyson

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