Stress (Load) testing.

Table of Contents

Apache HTTP server benchmarking tool

ab is a tool for benchmarking your Apache Hypertext Transfer Protocol (HTTP) server. It is designed to give you an impression of how your current Apache installation performs. This especially shows you how many requests per second your Apache installation is capable of serving.


  • multiple time test
  • content type
    • static
    • dynamic
  • KeepAlive (on/off)
    • allow multiple requests to be sent over the same TCP connection


ab -c 512 -n 102400 -g out-01.tsv ''


  • -c concurrency
  • -n requests
    • number of requests
  • -k
    • enable the HTTP KeepAlive feature
  • -g gnuplot-file
    • Write all measured values out as a ‘gnuplot’ or TSV (Tab separate values) file
  • -r
    • Don’t exit on socket receive errors


  • socket: Too many open files (24)
    • nofile too small, try ulimit -n 1024
  • apr_socket_recv: Connection reset by peer (54)
    • use ‘-r’ option