[ovs-discuss] a struct to keep flow scores

[Avi Cohen (A)]

Thanks Ben,
We need to test another eviction criteria - not LRU, 
but learn the flows other scores   such as flow effective time / flow usage , and to do eviction based on these scores
Best Regards
avi

> -----Original Message-----
> From: Ben Pfaff [mailto:blp at ovn.org]
> Sent: Thursday, 11 May, 2017 4:42 PM
> To: Avi Cohen (A)
> Cc: ovs-discuss at openvswitch.org
> Subject: Re: [ovs-discuss] a struct to keep flow scores
> 
> OVS already has mechanisms for this kind of thing.  For datapath flows, OVS
> already evicts flows based on these criteria.  For OpenFlow flows, OVS already
> supports approximate-LRU eviction.  I'm not sure what you're going to
> additionally get out of adding more to these mechanisms.  Do you have a high-
> level goal?
> 
> On Thu, May 11, 2017 at 06:42:26AM +0000, Avi Cohen (A) wrote:
> > Thanks  Ben,
> > The general idea is to store flow info (pkt, bytes, last_time_used)
> > which is updated every dumping phase and learn about flow behavior To
> calculate  flow-usage and and flow-span scores in order to evict  flows based
> this criteria.
> >
> > I thought of 2 implementation methods:
> > 1st  impl. Methiod
> > Store   the flow statistics  (pkt, bytes, last_time_used)  which is updated every
> dumping phase in a  flow ring-buffer
> > So we need to store info  of flows that are in openflow tables that
> > were installed  at least one time  at dp-cache and currently are or aren't in
> dp-cache The question is where to allocate this ring buffer ?
> >
> > 2nd impl. Method:
> > Maintain a global sliding window contains all flows statistics, then
> > at eviction phase - calculate the scores based on the sliding window
> information The question is where to allocate this sliding window ?
> > Best Regards
> > avi
> >
> >
> > > -----Original Message-----
> > > From: Ben Pfaff [mailto:blp at ovn.org]
> > > Sent: Thursday, 11 May, 2017 6:49 AM
> > > To: Avi Cohen (A)
> > > Cc: ovs-discuss at openvswitch.org
> > > Subject: Re: [ovs-discuss] a struct to keep flow scores
> > >
> > > On Wed, May 10, 2017 at 07:12:27AM +0000, Avi Cohen (A) wrote:
> > > > I need to keep some score information per flow - which exist in
> > > > the open-flow
> > > tables at user space , not necessarily in the data-path cache.
> > > > These scores are learned during flow dumping phase - but should be
> > > > saved
> > > also when flow is evicted from data-path.
> > > > The udpif_key struct is not suitable for this since it exist only
> > > > when flow exist
> > > in the data-path.
> > > > What is the suitable structure to keep this info ?
> > >
> > > What kind of information is this?  How to deal with it depends on what it is.