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On 07/01/13 18:32, Martijn Grooten wrote: > > ab? > > http://httpd.apache.org/docs/2.2/programs/ab.html ab is good for simple load testing. But what we Richard asked about is how it behaves in a browser, which can be radically different. As Matt suggests caching can make a big difference, but also things like social media plugins. One of the chat plugins I used on sites provided Avatars for the users, which were delivered with absolutely lousy cache values, and javascript that killed performance in some versions of Firefox (You make one setting change to the plugin and knock 60s of page load time kind of "killed"). All the developer plugins (Chrome, IE and Firebug for Firefox) all provide graphical views of page load, showing time taken for each component, with the option to show or hide cached items of various kinds. I usually use "ab" for finding what change to fetches per second a particular change makes on a particular page, but for things like themes, and plug-ins that include links to other sites, you need to look deeper, and it isn't always easy. For example when you test your DNS is probably already primed with results (or at least name servers for domains) of all the sites you are using, and the browser then caches this information again, where as a new visitor to your site might be fetching all this stuff from scratch. One issue we had was lousy server side caches of users data, which worked really well in the one or two user test server, and were inefficient in the real case. But then we've already gone to ripping out Google Analytics, and Facebook like, because they were a significant chunk of page load and don't add as much as you might think in many cases. Some Wordpress sites also give you some stats to play with such as: http://stackoverflow.com/questions/14873/how-do-i-display-database-query-statistics-on-wordpress-site which can be useful if you don't have nice well connected server to test other well connected servers, or don't want to set it all up locally (usually a good plan with a site). Appreciate a lot of folks (myself included some times) are dangling off variable size bits of wet string, which adds a larger layer of unpredictability than server variability in some cases, resulting in of course the need to run more tests, and burn more precious bandwidth, to get reliable results. PS: I don't think Wordpress is "Off topic", it is free software, and is predominantly run on GNU/Linux. -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/listfaq