Message 217372 - Python tracker

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Author	neologix
Recipients	alex, benjamin.peterson, christian.heimes, dstufft, giampaolo.rodola, janssen, josh.r, ncoghlan, neologix, tshepang
Date	2014年04月28日.13:34:01
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<CAH_1eM3W4-FU5VyFyeVQvY4RZf1F3KhKWkTDUKSKc6k3kLfrpg@mail.gmail.com>
In-reply-to	<1398689553.1.0.00973656515503.issue21305@psf.upfronthosting.co.za>

Content
> Using os.urandom is the right thing to do for getting random in an application, but the current implementation effectively punishes people who use it if their application is highly concurrent. And I argue that this scenario is almost as likely as the one you depict above: we never had a bug report before, and if you have a look at the the bug report which led to the change in question, it's not clear at all that all threads were indeed reading from /dev/urandom when EMFILE was raised. Since reading from /dev/urandom shouldn't block, it's not clear at all how a realistic workload would actually hit the file descriptor limit because RLIMIT_NOFILE threads are reading from /dev/urandom. But don't get me wrong, I'm not saying this change is useless, it actually makes sense to use a persistent FD. But backporting always has a risk, which has to be balanced.

Content

> Using os.urandom is the *right* thing to do for getting random in an application, but the current implementation effectively punishes people who use it if their application is highly concurrent.
And I argue that this scenario is almost as likely as the one you
depict above: we never had a bug report before, and if you have a look
at the the bug report which led to the change in question, it's not
clear at all that all threads were indeed reading from /dev/urandom
when EMFILE was raised. Since reading from /dev/urandom shouldn't
block, it's not clear at all how a realistic workload would actually
hit the file descriptor limit because RLIMIT_NOFILE threads are
reading from /dev/urandom.
But don't get me wrong, I'm not saying this change is useless, it
actually makes sense to use a persistent FD. But backporting always
has a risk, which has to be balanced.

History
Date	User	Action	Args
2014年04月28日 13:34:01	neologix	set	recipients: + neologix, ncoghlan, janssen, giampaolo.rodola, christian.heimes, benjamin.peterson, alex, tshepang, dstufft, josh.r
2014年04月28日 13:34:01	neologix	link	issue21305 messages
2014年04月28日 13:34:01	neologix	create

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