{"id":1223,"date":"2012-06-17T19:53:02","date_gmt":"2012-06-17T18:53:02","guid":{"rendered":"http:\/\/kudzia.eu\/b\/?p=1223"},"modified":"2012-06-18T06:23:30","modified_gmt":"2012-06-18T05:23:30","slug":"higher-tcp-icw-real-world-tests","status":"publish","type":"post","link":"https:\/\/kudzia.eu\/b\/2012\/06\/higher-tcp-icw-real-world-tests\/","title":{"rendered":"higher TCP ICW &#8211; real world tests"},"content":{"rendered":"<p><a href=\"http:\/\/samsaffron.com\/archive\/2012\/03\/01\/why-upgrading-your-linux-kernel-will-make-your-customers-much-happier\">this<\/a> post inspired me to check how much performance can we gain by just upgrading to more recent kernel on the internet-facing proxy servers at work.<br \/>\n<!--more--><br \/>\ni&#8217;ve run few benchmarks timing repeated HTTP\/1.0 downloads with server located in Szczecin &#8211; Poland and one client in Hong Kong [ ~350ms ], another client in Stockholm &#8211; Sweden [ ~44ms ]. first test was run with proxy server running debian&#8217;s stock kernel 2.6.32, second &#8211; with 3.2.0 from backports.<\/p>\n<p>benchmark results:<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/docs.google.com\/spreadsheet\/pub?key=0Au9ThZ9PVUwldDlYeXc3Q3VCeWpsYUtMQlBwczdmbmc&amp;single=true&amp;gid=0&amp;range=a1%3Ah7&amp;output=html&amp;widget=true\" frameborder=\"0\" width=\"790\" height=\"170\"><\/iframe><\/p>\n<p>full data &#8211; <a href=\"https:\/\/docs.google.com\/spreadsheet\/ccc?key=0Au9ThZ9PVUwldDlYeXc3Q3VCeWpsYUtMQlBwczdmbmc\">here<\/a> or <a href=\"https:\/\/kudzia.eu\/b\/wp-content\/uploads\/2012\/06\/201206-tcp-icw.xls\">here<\/a>.<\/p>\n<p>all in all this looks promising and gives reasonable speedup that will be useful in our case [downloads of gzipped xmls each ~5-10kB after compression, occurring every few minutes which is rarely enough not to benefit from persistent http connections].<\/p>\n<p>side notes:<\/p>\n<p>installation of backports kernel for debian:<\/p>\n<pre>echo http:\/\/backports.debian.org\/debian-backports squeeze-backports main &gt;&gt; \/etc\/apt\/sources.list\r\napt-get update\r\napt-get install -t squeeze-backports linux-image-3.2.0-0.bpo.2-686-pae\r\nreboot<\/pre>\n<p>methodology: for each size, location and kernel version i&#8217;ve run 100 downloads using <a href=\"http:\/\/httpd.apache.org\/docs\/2.0\/programs\/ab.html\">ab<\/a>. for each of measurement sessions i&#8217;ve rejected 2 slowest downloads.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>this post inspired me to check how much performance can we gain by just upgrading to more recent kernel on the internet-facing proxy servers at work.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[47,40],"class_list":["post-1223","post","type-post","status-publish","format-standard","hentry","category-tech","tag-linux-networking","tag-performance"],"_links":{"self":[{"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/posts\/1223","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/comments?post=1223"}],"version-history":[{"count":18,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/posts\/1223\/revisions"}],"predecessor-version":[{"id":1246,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/posts\/1223\/revisions\/1246"}],"wp:attachment":[{"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/media?parent=1223"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/categories?post=1223"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kudzia.eu\/b\/wp-json\/wp\/v2\/tags?post=1223"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}