Push queues: No. of running tasks < No. of tasks in queue < Max number of concurrent tasks

[Manuele Cavalli-Sforza]

I have a push queue with a number of long running tasks enqueued. I notice that the push queue has reached a state, however, where the No. of running tasks < No. of tasks in queue < Max number of concurrent tasks. 

This is unideal, as I would like the queue to be processing at its maximum capacity. Does this have to do with the bucket size set on the queue? Would tweaking this alter the queue's responsiveness? 

It is also relevant to note that I updated the queue configuration, after adding the tasks, to be a max of 40 concurrent tasks. Also, I added the tasks all at the same time. I noticed that the queue initially processed the tasks well at the original 20 concurrent task limit, but -- when updated to 40 concurrent tasks -- did not seem to respond, and always kept a task running number of under 20. Any insights from other users' experience or the Google team? 

Thanks,

Manni

[Manuele Cavalli-Sforza]

Attempted to tweak batch_size and rate since posting and have not seen differences.

[Kaan Soral]

It could be instance related, if your instances are not aggressive, it might occur

If tasks use too much memory etc., it might be hard to run them, my .02

[Kim Lewandowski]

Hi Manni,

It sounds like 1 of 2 things is happening:

1. Queue depth is not accurate. We are actively working on improving the accuracy of this number (it's a really hard problem to solve!)

2. You may have tasks scheduled to run in the future (either intentionally or because they are being retried)

If you want to email me your application ID and queue name, we could dig in and see what's going on. lil...@google.com

-Kim

App Engine, Product Manager

[Manuele Cavalli-Sforza]

Both valid thoughts, will keep these in mind, if I see this behavior, in the future!