I've heard from several sources that Google App Engine Instances have a hard limit of 10 concurrent request. I was wondering if someone could clarify what exactly this means.
Does the scheduler block any requests over the 10, or is this enforced through a limit on concurrent threads?
Specifically, does this limit affect Go instances the same way that it does Python and Java?
EDIT: here's the feature request which will allow App Engine Instance to handle more then 10 concurrent request / threads. Allow configurable limit of concurrent requests per instance. Please star it.
This has been fixed as of Nov 18th 2013.
The maximum number of requests any GAE instance can process is now configured via the max_concurrent_requests setting eg:
runtime: go
api_version: go1
automatic_scaling:
max_concurrent_requests: 80
handlers:
- url: /.*
script: _go_app
The default is 8 and the maximum is 80.
See https://cloud.google.com/appengine/docs/python/config/appref#automatic_scaling for more info.
As of July 12, 2012, it's the latter. The 10 concurrent limit is enforced through a limit on concurrent threads on every runtime. Most of such cases, our scheduler will try to spin up a new instance.
Please also see the e-mail from jonmac on this thread: https://groups.google.com/d/msg/google-appengine/y-LnZ2WYJ5Q/j_w13F4oSSkJ