Tuesday, October 24, 2023

In-network processing - do we ever really need it?

 We've looked at this problem from several sides now - to solve the "incast", to do aggregation for map/reduce or any federated learning platform, to aggregate acknowledgements for PGM.

When we say "in-network", we're talking about in-switch processing - borrowing resources from the poor P4 switch to store and process multiple application layer packets worth of stuff, so that only one actual packet (or at least a lot less) needs to be sent on its way.

So how about we compare with multicast (in network copying) and its (largely) replacement by CDNs/overlays.

Key point is branches in the net - this is where the "implosion" (for incast) or "explosion" (for multicast) happens:

So do we have a server nearby? Or can we just put one there (or just connect one there?

Answer is (for multicast yes:

netflix/pops in wide area - use distribution trree to all pops, and caches

So in data center: 

use servers, not switches and build sink forest of trees

clos system, connect servers to local switch, top of rack, and spine switch/server...then for servers at some level, use a node at the next level up as aggregation server (note Clos even has redundancy so this will survive edge/switch outages)

Friday, October 13, 2023

Unseeing like a State

 Just read Seeing like a state, by James C. Scott.  Incredible scope and vision for what is often, but not always) wrong with "tech" led solutions - though in a very broad sense. - looks at imposition of regularised/normalized villages, farming, transport, city structures and so on, especially by "developed" world on the (frequently) completely inappropriate contexts of colonies but also post colonial, self imposted. From russian collective farms, to modernist cities like Brasilia, from mono-culture farming to single-minded, wrong-headed cultural impositions, an amazing read!

It basically makes it pretty obvious why the following stuff happens:-

Tim Wu's Eyeball Bandits

Ian Hislop's Fake News

Doctorow's Drain Overflow

Basically, the Internet users are the hunters and gatherers that just got fenced in and collectively farmed, like ants. Grate.

Blog Archive

About Me

My photo
misery me, there is a floccipaucinihilipilification (*) of chronsynclastic infundibuli in these parts and I must therefore refer you to frank zappa instead, and go home