ApacheBench (ab) is a single-threaded command line tool used for measuring the performance of HTTP web servers. Originally designed to test the Apache HTTP Server, it is generic enough to test any web server.
The ApacheBench tool comes bundled with the standard Apache web server and like Apache is open source software distributed under the terms of the Apache License.
Passing the authenticated user cookie to Drupal
The ‘-C’ (uppercase) parameter is used with ApacheBench to specify a cookie. This parameter is case sensitive and should not be confused with ‘-c’ (lowercase) which specifies the number of concurrent requests ApacheBench will make.
Cookie: … SESSbeef3b8bc10ef53ca5a37a0c409b57b6=ncP2hRnsM4sDZweniV0pSbGGARoTklWyGFww2A-beef …
Authenticated: Authenticated user test
ab -n 1000 -c 10 -C 'SESSbeef3b8bc10ef53ca5a37a0c409b57b6=ncP2hRnsM4sDZweniV0pSbGGARoTklWyGFww2A-beef' http://stress.my.site/
Unauthenticated: Anonymous user test
ab -n 1000 -c 10 http://stress.my.site/
While ApacheBench provides useful information about a web server’s performance, it does not predict how a production system will perform under real load from live users.