{"id":1811,"date":"2009-04-30T07:16:56","date_gmt":"2009-04-30T07:16:56","guid":{"rendered":"http:\/\/justthesam.com\/2009\/04\/apache-bench-notes\/"},"modified":"2009-04-30T07:16:56","modified_gmt":"2009-04-30T07:16:56","slug":"apache-bench-notes","status":"publish","type":"post","link":"https:\/\/justthesam.com\/?p=1811","title":{"rendered":"Apache Bench Notes"},"content":{"rendered":"
Many people don't know about Apache Bench, even though it may be installed on their system. For instance it's installed on Mac OS X by default. It's a very simple command line utility to perform basic stress\/performance testing of websites. It can request a given URL repeatedly, then report back statistics. I generally use it in this form:<\/div>\n

<\/p>\n

> ab -n 100 -c 4 http:\/\/www.somewebsite.com\/test\/page.htm<\/span><\/div>\n

<\/p>\n

Dissecting that command:<\/div>\n
\n
    \n
  • ab is the Apache Bench executable itself (found in \/usr\/sbin on my machine)<\/li>\n
  • -n 100 tells it to send the request 100 times<\/span> <\/li>\n
  • -c 4 tells it to use 4 concurrent threads to do so<\/span><\/li>\n
  • finally we have the URL itself.<\/span> <\/li>\n<\/ul>\n

    Even though it's simple, there are some important gotchas worth knowing about:<\/p><\/div>\n

    \n
      \n
    • Remember to put the URL in single quotes if it contains characters that would otherwise be interpreted by the shell. This is often the case for any URL with a query string, as the & characters will mess things up otherwise. <\/li>\n
    • If using a base URL for a site (just host name), you must use a trailing slash. http:\/\/foo.com doesn't work, but http:\/\/foo.com\/ does work.<\/span> <\/li>\n
    • Quite often you may see in the statistics "Failed requests: 5" or similar, followed by a list of the types of failure: "(Connect: 0, Receive: 0, Length: 5, Exceptions: 0)". If the only type of failure that actually occurred is 'Length' then don't be alarmed. This simply means that each request (for the same URL) returned a different length response, which ab regards as suspicious. However it's perfectly normal for dynamic webpages, especially if they include the time or other very dynamic data on the page.<\/span> <\/li>\n
    • I find on one of my machines that it just doesn't like localhost as a hostname, so I have to use 127.0.0.1 instead. I have no idea why, as localhost works fine in other contexts on the same machine.<\/span> <\/li>\n<\/ul>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

      Many people don't know about Apache Bench, even though it may be installed on their system. For instance it's installed on Mac OS X by default. It's a very simple command line utility to perform basic stress\/performance testing of websites. It can request a given URL repeatedly, then report back statistics. I generally use it […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,22,33],"tags":[],"class_list":["post-1811","post","type-post","status-publish","format-standard","hentry","category-mac","category-programming","category-webtech"],"_links":{"self":[{"href":"https:\/\/justthesam.com\/index.php?rest_route=\/wp\/v2\/posts\/1811","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/justthesam.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/justthesam.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/justthesam.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/justthesam.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1811"}],"version-history":[{"count":0,"href":"https:\/\/justthesam.com\/index.php?rest_route=\/wp\/v2\/posts\/1811\/revisions"}],"wp:attachment":[{"href":"https:\/\/justthesam.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1811"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/justthesam.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1811"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/justthesam.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1811"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}