Concurrency
How many simultaneously open connections must a server handle?
- 1,000,000 hits per day
- 12 hits per second average
- upwards of 50 hits per second peak (bursts, diurnal cycle)
- latency:
- 10 milliseconds (out of memory) ==> 1 connection
- 50 milliseconds (off of disk) ==> 3 connections
- 200 milliseconds (CGI + disk) ==> 10 connections
- 5 seconds (CGI to DB gateway) ==> 250 connections
Depending on expected usage, need very different concurrency models