[ovs-discuss] Setting the tcp buffer

[Deepak Singh]

We are creating the priority queue .For low priority packet-in packets are pre-empted . So high priority packet-in cannot be send to odl when TCP buffer on the openflow switch is congested . To avoid the problem ,TCP buffer size has to be configurable if needed.

-----Original Message-----
From: Ben Pfaff [mailto:blp at nicira.com] 
Sent: 14 January 2015 11:17
To: Deepak Singh
Cc: discuss at openvswitch.org
Subject: Re: [ovs-discuss] Setting the tcp buffer

I'd like a better explanation of the problem first.  So far, your explanation is so barebones that I'm not confident that TCP buffer size is the solution.

On Wed, Jan 14, 2015 at 05:44:47AM +0000, Deepak Singh wrote:
> Could you suggest the way i can do this ?
> 
> -----Original Message-----
> From: Ben Pfaff [mailto:blp at nicira.com]
> Sent: 14 January 2015 10:47
> To: Deepak Singh
> Cc: discuss at openvswitch.org
> Subject: Re: [ovs-discuss] Setting the tcp buffer
> 
> I'm afraid that none of this makes sense to me, sorry.
> 
> On Wed, Jan 14, 2015 at 05:14:49AM +0000, Deepak Singh wrote:
> > I am using the unix socket . From ovs-vsctl side i am opening a client socket who send the size of the TCP buffer . And ovs-vswitchd side i am opening the server socket who keep running for client and receive the buffer size and call the setsockopt for fd .
> > For this FD i am creating a new thread who will get the stream->fd(br->ofproto->ofconn->rconn->vconn_stream->stream->fd) . But one problem is coming when i using HMAP_FOR_EACH (br, node, &all_bridges) and further calling the find_controller_by_target to get ofconn pointer but this ofconn is coming NULL .
> > 
> > 
> > -----Original Message-----
> > From: Ben Pfaff [mailto:blp at nicira.com]
> > Sent: 14 January 2015 10:23
> > To: Deepak Singh
> > Cc: discuss at openvswitch.org
> > Subject: Re: [ovs-discuss] Setting the tcp buffer
> > 
> > It's hard to imagine how ovs-vsctl can change the TCP buffer sizes in ovs-vswitchd, maybe you could explain further?
> > 
> > On Wed, Jan 14, 2015 at 02:02:13AM +0000, Deepak Singh wrote:
> > > packet-in high priority cannot be sent to ODL when TCP buffer on the OFS is congested .
> > > Yes lib/stream-tcp.c has the code but i have to hand-tune  from ovs-vsctl binary. 
> > > 
> > > ________________________________________
> > > From: Ben Pfaff [blp at nicira.com]
> > > Sent: 14 January 2015 02:48:19
> > > To: Deepak Singh
> > > Cc: discuss at openvswitch.org
> > > Subject: Re: [ovs-discuss] Setting the tcp buffer
> > > 
> > > On Tue, Jan 13, 2015 at 08:49:01AM +0000, Deepak Singh wrote:
> > > > How can i get the socket fd (send socket) ?  Is the stream_fd  data structure which i have to get ?
> > > > Actually i am tuning the tcp buffer size from the ovs-vsctl . ovs-vsctl and ovs-vswitch are different binary so i am using the unix sockets to access the socket fd . Is it the right approach ?
> > > 
> > > What are you really trying to accomplish?  It isn't usually useful 
> > > to hand-tune TCP buffer sizes.
> > > 
> > > lib/stream-tcp.c has the code that opens and accepts TCP 
> > > connections, so that might be a good place to adjust buffer size.