Re: [PATCH] SO_REUSEADDR and SO_REUSEPORT behaviour

Also some discussions and improvements to it.

http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2013-09/msg00165.html


On Fri, Nov 29, 2013 at 7:42 PM, Ermal Luçi <eri_at_freebsd.org> wrote:

> Well seems Dragonfly has some version of it already from commit [1].
>
> In FreeBSD there is the framework for this with by defining PCBGROUP.
> Also the explanation of it at [2] and [3].
> It can achieve approximately the same features of SO_RESUSEPORT of linux.
> The only thing missing is the marketing behind it and i think and better
> RSS support.
> By looking at dates the support is there before linux so all you guys
> looking for it can experiment with it.
>
> What i was trying to accomplish was something else from performance
> improvement and
> maybe put a sysctl behind it to make it more acceptable..
>
> [1]
> http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/740d1d9f7b7bf9c9c021abb8197718d7a2d441c9
> [2]
> http://fxr.watson.org/fxr/source/netinet/in_pcbgroup.c?im=bigexcerpts#L51
> [3] http://lists.freebsd.org/pipermail/svn-src-head/2011-June/028190.html
>
>
> On Fri, Nov 29, 2013 at 7:03 PM, Oleg Moskalenko <mom040267_at_gmail.com>wrote:
>
>> Tim, you are wrong. Read what is "multicast" definition, and read how UDP
>> and TCP sockets work in Linux 3.9+ kernels.
>>
>> Oleg .
>>
>>
>> On Fri, Nov 29, 2013 at 9:59 AM, Tim Kientzle <kientzle_at_freebsd.org>wrote:
>>
>>>
>>> On Nov 29, 2013, at 4:04 AM, Ermal Luçi <eri_at_freebsd.org> wrote:
>>>
>>> > Hello,
>>> >
>>> > since SO_REUSEADDR and SO_REUSEPORT are supposed to allow two daemons
>>> to
>>> > share the same port and possibly listening ip …
>>>
>>> These flags are used with TCP-based servers.
>>>
>>> I’ve used them to make software upgrades go more smoothly.
>>> Without them, the following often happens:
>>>
>>> * Old server stops.  In the process, all of its TCP connections are
>>> closed.
>>>
>>> * Connections to old server remain in the TCP connection table until the
>>> remote end can acknowledge.
>>>
>>> * New server starts.
>>>
>>> * New server tries to open port but fails because that port is “still in
>>> use” by connections in the TCP connection table.
>>>
>>> With these flags, the new server can open the port even though
>>> it is “still in use” by existing connections.
>>>
>>>
>>> > This is not the case today.
>>> > Only multicast sockets seem to have the behaviour of broadcasting the
>>> data
>>> > to all sockets sharing the same properties through these options!
>>>
>>> That is what multicast is for.
>>>
>>> If you want the same data sent to all listeners, then
>>> that is multicast behavior and you should be using
>>> a multicast socket.
>>>
>>> > The patch at [1] implements/corrects the behaviour for UDP sockets.
>>>
>>> You’re trying to turn all UDP sockets with those options
>>> into multicast sockets.
>>>
>>> If you want a multicast socket, you should ask for one.
>>>
>>> Tim
>>>
>>> _______________________________________________
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>>>
>>
>>
>
>
> --
> Ermal
>



-- 
Ermal