I've been seeing really slow scp performance on our 10G core network, like dialup sort of speeds. Turns out the root cause was something I committed to my ~/.ssh/config more than twenty years ago:
Host *
Compression yes
@th Indeed! it's counter intuitive that it's faster to transfer than to compress nowadays :)
@colin_mcmillen @th I'm not certain that's true, and I think the devil may be in the details here. I know that @tastytronic did his dissertation on measuring compression tradeoffs, and the one thing he told us at the time was to just always do at least zlib level 1 compression on anything that goes over the wire, if you can.
@spacehobo @colin_mcmillen @th @tastytronic
Is It possible to set it up in a way that compression is somehow parallelized across cores?
I have no idea and it's probably something very complex, but you never know.
