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Speculation about NIC hardware being improved with regards to latency.
- people seem to think certainly possible, but unsure whether it will
get fast enough
Mendel & others on some NICs having complex microcode for multiple ring buffers,
virtualization, etc.
- big vendors, however (intel, broadcom), generally have functionality
in silicon, not microcode – faster
Suggestions to use infiniband, or something other fancy, for prototyping.
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Question about retransmit rates expected
- nobody seems to have data
Jeff Mogul brings up incast problem
- overflowing buffers in intermediate switches bad, leads to secondary
failures (synchronization possible)
Retransmit whole requests? If loss rare, why not?
- partial retransmits could reduce probability of incast problem
What happens when there's network congestion?
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Jeff Dean: Use second core that shares same cache as the RPC handler core to
prefetch packet data into cache.
- no synch. needed
Keith Adams again: plug this stuff into memcached!