Need advice on sys5 shm and zero copy sockets

[Eduardo Morras]

Don't have original message, i reply to a reply sorry.

> On 2/8/13 4:22 AM, gary mazzaferro wrote:
> > Hi,
> >
> > I was told to post this question here (Ken Merry), it would be a good
> > place to get some help. I'm not sure this is doable without a kernel
> > module, which I don't want to add.
> >
> > I'll explain what I'm attempting..
> >
> > I'm designing a high speed rest motor for cloud execution environment.
> >
> > 1) I'd like to eliminate copy from the tcp stack to the application(s).
> >
> > 2) I'm also sharing the buffers across processes and jails. So I'd
> > like to preserve the zero-copy in a msg pipe/unix socket
> >
> > 3) Some buffers will go to disk file systems.
> >
> >
> > Wish list:
> > 4) I'd like it to work with sctp because I like it for local  networking :)
> >
> > 5) I'd like to provision memory pools on a per
> > application/connection/ip port basis.
> >
> > Ultimate Goal:
> > 6) Additionally, I'm injecting "code" from a foreign process into the
> > workflow of another process (state machine). The connection between
> > them will be a signal and shared state information.
> >
> > I'm assuming item (6) is a separate issue, but it may impact the direction..
> >
> > I've tried shm with zero copy sockets with linux and it just will not work !!
> >
> > BTW, I'm returning to freebsd after far too many years
> >
> > cheers,
> > gary

For question (1)

Are you using secure rest with TLS/SSL? Does your rest implementation uses openssl? If yes to both, then you don't need to use tcp. SSL already does all the work tcp does, resending lost/damaged packets and reordering received packets, so you can use plain udp without much pain. Openssl has since 0.9.8 this capability implemented with udp, don't remember if udplite.

Check RFC 6347

HTH

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Eduardo Morras <emorrasg at yahoo.es>