Re: [PATCH net-next] sctp: support per-association stats via a new SCTP_GET_ASSOC_STATS call

On Mon, Oct 29, 2012 at 04:11:50PM -0400, Vlad Yasevich wrote:

On 10/29/2012 12:38 PM, Neil Horman wrote:

quoted

On Sat, Oct 27, 2012 at 11:48:33AM -0400, Vlad Yasevich wrote:

quoted

On Oct 27, 2012, at 7:35 AM, Michele Baldessari [off-list ref] wrote:

quoted

Hi Neil & Vlad,

On Fri, Oct 26, 2012 at 10:37:04AM -0400, Neil Horman wrote:

quoted

We already have files in /proc/net/sctp to count snmp system-wide totals,
per-endpoint totals, and per association totals.  Why do these stats differently
instead of just adding them the per-association file?  I get that solaris does
this, but its not codified in any of the RFC's or other standards.  I would
really rather see something like this go into the interfaces we have, rather
than creating a new one.

I also am a bit confused regarding the stats themselves.  Most are fairly clear,
but some seem lacking (you count most things sent and received, but only count
received gap acks).  Others seems vague and or confusing (when counting
retransmitted chunks and packets, how do you count a packet that has both new
and retransmitted chunks)?  And the max observed rto stat is just odd.  Each
transport has an rto value, not each association, and you cal already see the
individual transport rto values in /proc/net/sctp/remaddr.

thanks a lot for your time reviewing this. I will try to address all
your comments in a second version of the patch. One thing I am not too
sure though: do you prefer me extending /proc/net/sctp/* or implement a
new call.

I ask because from a previous private communication with Vlad the new
socket option seemed to be the preferred approach.
I am fine either way just let me know ;)

socket option is preferable as /proc doesn't scale very well as number of associations grows.

-Vlad

I completely agree with that notion, but at the same time, the socket option is
limited in that these stats will only be accessible to the process that owns the
socket.  I imagine that someone will eventually ask for these stats to be made
available to utilities outside of the owning socket.
Neil

I am sure they will, but I know of several applications that as part
of debugging information periodically fetch the stats.  For them it
is much simpler to use socket options.

-vlad

Ok, fair enough.
Neil

quoted

quoted

quoted

cheers,
--
Michele Baldessari            [off-list ref]
C2A5 9DA3 9961 4FFB E01B  D0BC DDD4 DCCB 7515 5C6D

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