[openstack-dev] [oslo.db] PyMySQL review

Joshua Harlow harlowja at outlook.com
Thu Jan 29 00:14:18 UTC 2015


Will be an interesting analysis; I've also never understood this desire 
to use eventlet (perhaps it's written somewhere?). It seems like most of 
the applications in openstack (maybe leaving out the WSGI entrypoints) 
can be scaled horizontally and mostly just do a large amount of work 
that blocks (and python afaik itself will swap in/out threads when this 
happens) on I/O, sockets, other...

The highly concurrent situation seems only *slightly* applicable on the 
WSGI/webserver entrypoints (although this IMHO is 'meh', since we have 
multiple workers here anyway, and those should be scalable with new 
processes if needed) and maybe 'conductor' applications (although this 
should also be horizontally scalable using child-processes if it's 
really a bottleneck).


Johannes Erdfelt wrote:
> On Wed, Jan 28, 2015, Clint Byrum<clint at fewbar.com>  wrote:
>> As is often the case with threading, a reason to avoid using it is
>> that libraries often aren't able or willing to assert thread safety.
>> That said, one way to fix that, is to fix those libraries that we do
>> want to use, to be thread safe. :)
> I floated this idea across some coworkers recently and they brought up a
> similar concern, which is concurrency in general, both within our code
> and dependencies.
> I can't find many places in Nova (at least) that are concurrent in the
> sense that one object will be used by multiple threads. nova-scheduler
> is likely one place. nova-compute would likely be easy to fix if there
> are any problems.
> That said, I think the only way to know for sure is to try it out and
> see. I'm going to hack up a proof of concept and see how difficult this
> will be.
> JE
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

More information about the OpenStack-dev mailing list