As said elsewhere.... don't adjust the "richness" controls on your kernel unless there's an actual scalability problem costing you $$. Your special "tweaks" wi

As said elsewhere.... don't adjust the "richness" controls on your kernel unless there's an actual scalability problem costing you $$. Your special "tweaks" will end up using more memory or slowing performance most of the time. sysctls should be sensible by default on RH (cent/sci/cern/aws) and Ubuntu based kernels. The two most common encountered problems are incast TCP collapse and slow clients. https://everythingisdata.wordpress.com/2009/09/25/fine-grained-tcp-retransmissions/ https://everythingisdata.wordpress.com/2009/09/25/fine-grain... http://www.pdl.cmu.edu/Incast/ http://www.pdl.cmu.edu/Incast/ http://conferences.sigcomm.org/sigcomm/2009/workshops/wren/papers/p73.pdf http://conferences.sigcomm.org/sigcomm/2009/workshops/wren/p... (For TCP testing: iperf... remember to account for protocol overhead, bits/bytes) Handling slow clients is app-specific, so there's no general advice other than don't get clever. Clever -> !debuggable -> !maintainable -> !scalable.