[X2go-Dev] libssh, nagle, and performance issues

[John A. Sullivan III]

Hello, all.  Since moving to the newer clients using libssh, I've
noticed what appears to be a performance degradation.  It smells like
Nagle coalescing packets, e.g., most of the screen will paint, then it
will pause a moment, and then the rest will paint.  Is there any chance
we have neglected to disable Nagle when invoking libssh?

This appears to have affected the SNMP over SSH project:
http://books.google.com/books?id=S62is2vVoVgC&pg=PA29&lpg=PA29&dq=libssh
+nagle&source=bl&ots=F8Iw-pvQxd&sig=f5dfy0K0ewzSZOhqzTJRSKsDKZ8&hl=en&ei=KppzTrCZD4LJgQeMxLzzDA&sa=X&oi=book_result&ct=result&resnum=1&sqi=2&ved=0CBwQ6AEwAA#v=onepage&q=libssh%20nagle&f=false

This is in section 4.1. The difference was a latency of over 800ms to
one of under 60ms.  That seems to be about what I am seeing. There is a
delay of roughly a second and then the rest of the screen comes through.
Thanks - John