Illumos/SmartOS/Solaris issue when using eventport and keepalive at the same time

[Maxim Dounin]

Hello!

On Fri, Mar 17, 2017 at 11:46:46AM +1300, Peter Toth wrote:

> There is a lock-up issue on Solaris derived operating systems when using
> "keepalive" and "use eventport" configuration directives at the same time.
> 
> The issue has been described previously back in 2015 and a patch was
> proposed here: https://forum.nginx.org/read.php?2,259798,259798#msg-259798
> 
> I have tested the patch and it is working.
> 
> Could anyone comment on whether the patch looks acceptable in its current
> form?
> Any objections to applying this fix in the next release?

There are problems with eventport implementation, known for at 
least several years now, and these can be easily reproduced by 
running our test suite with 'use eventport' added to test 
configurations.  If I recall correctly, upstream keepalive is not 
something important to trigger problems, any connection to an 
upstream is basically enough.

Unfortunately, these problems are very low priority due to 
minor popularity of Solaris.  Consider using /dev/poll instead, 
which is the default, well tested and has no known problems.

The patch in question looks more like a hack to mitigate a 
particular issue the author was facing.  It doesn't resolve the 
underlying problems though, and likely there are other issues as 
well.  There are no plans to commit this patch.

-- 
Maxim Dounin
http://nginx.org/