Re: compressed TIME-WAIT to be decomissioned

On Wed, Jan 12, 2022 at 10:48:59AM -0800, Gleb Smirnoff wrote:
T> * Many of HTTP connections were made by older browsers, which were not able
T>   to use persistent HTTP connections.  Those browsers that could, would
T>   recycle connections more often, then today.  Default timeouts in Apache
T>   for persistent connections were short.  So, the ratio of connections
T>   in TIME-WAIT compared to live connections was much bigger than today.
T>   Here is sample data from 2008 provided to me by Igor Sysoev:
T> 
T>   ITEM         SIZE     LIMIT      USED      FREE  REQUESTS  FAILURES
T>   tcpcb:        728,   163840,    22938,    72722, 13029632,        0
T>   tcptw:         88,   163842,    10253,    72949,  2447928,        0
T> 
T>   We see that TIME-WAITs are ~ 50% of live connections.
T> 
T>   Today I see that TIME-WAITs are ~ 1% of connections. My data is biased
T>   here, since I'm looking at servers that do mostly video streaming. I'd
T>   be grateful if anybody replies to this email with some other modern data
T>   on ratio between tcpcb and tcptw allocations.

Yes, my data was quite biased. I found evidence that for smaller assets served
by HTTP the ratio of tcptw/tcpcb can be up to 35% these days.

-- 
Gleb Smirnoff