[tor-bugs] #7707 [Tor]: Impose a minimum write size for TLS writes

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#7707: Impose a minimum write size for TLS writes
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 Reporter:  nickm                  |          Owner:                    
     Type:  defect                 |         Status:  new               
 Priority:  normal                 |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor                    |        Version:                    
 Keywords:  tor-relay performance  |         Parent:                    
   Points:                         |   Actualpoints:                    
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 Reported pseudonymously:

 If our TokenBucketRefillInterval is very low, we'll frequently wind up
 with very small writes, which can be exceptionally bad with TLS.  One
 answer is to say "don't do that then" and keep TokenBucketRefillInterfal
 to about 100msec or so.  Another answer is to nagle our TLS writes, and
 never write less than the full amount in the output buffer, or one cell,
 whichever is smaller.

 For non-TLS writes, the kernel should nagle for us, so we're probably
 fine, though it might be sensible to impose a write threshold there too.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7707>
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