Load Testing Blog
IE 11 Support Added in Latest Load Tester 5.5 patch
Earlier last month, Microsoft began rolling out IE 11 updates for Windows 7 users. Now, with the most recent release of Load Tester 5.5, you can rest assured that Load Tester will continue to allow you to record your testcases using the upgraded IE 11.
IE 11 includes a number of new enhancements (many of which are reserved for Windows 8.1 customers). However, on Windows 7, users can still benefit from improved performance and standards support.
One of the interesting modifications of note is a new change to IE’s user agent header. Starting with IE 11, the … Continue reading »
Google Pagespeed 1.1 Performance with PHP
For the past week I’ve been testing out the performance of the new Google Pagespeed module for Apache, mod_pagespeed, and with the memory locking option turned on, the performance was a definite improvement for static pages. The fact is, though, there are much faster web servers for static content, and CDNs make scaling static pages very, every easy. Standard testing procedure, though, is to start as simple as possible, and test every variation separately. The next step, then is to test how Pagespeed works on dynamic pages.
As before, this new test uses our own corporate site, except now … Continue reading »
Google Pagespeed 1.1 Scalability with Memory Locking
In last week’s blog post looking at the overhead of running Google Pagespeed, there was a marked scalability penalty to be paid that was caused by an approximate doubling of CPU load. Several people suggested some options to try, the easiest of which was turning on an experimental memory locking option. (The default mod_pagespeed config uses file locking.) I was also informed as to the plethora of tuning options to tailor the behavior to each site, but decided to keep it simple and experiment with each option separately. As with Apache itself, there’s lots … Continue reading »
Google Pagespeed Scalability Benchmark
Premise
Google Pagespeed is an easy way to optimize web page rendering time without having to recode your website. The pagespeed analyzer gives suggestions on what needs to be changed, while mod_pagespeed is an Apache add-on that makes those modifications automagically.
The one question that hasn’t been answered is “what is the performance cost for installing mod_pagespeed”. Pagespeed addresses only client-side performance, which is completely different from server scalability. The actual page load times that customers see in practice is affected by both the page design and layout, and the actual speed of the server under load. … Continue reading »
Setting Apache2 ulimit for Maximum Performance
As strange as it seems, when you start up the standard RedHat or CentOS release, it is not configured for running Apache2 with any sort of performance! In fact, even on a large server you’ll be lucky to handle 100 concurrent users on even simple web pages. So many websites have very few visitors so often its not noticeable, but even if you adjust all of the other apache2 settings, if you don’t bother to adjust the ulimits, the site will be handicapped by really bad performance.
Web Performance Consulting
The Fastest Webserver?
Looking for the snappiest, fastest web server software available on this here internet? So were we. Valid, independent, non-synthetic benchmarks can be difficult to find. Of course, we all know that benchmarks don’t tell us everything we need to know about real-world performance; but what’s the fun of having choices if we can’t pick the best?
Exactly. I decided to do a little research project of my own.
Test Plan
I selected for this exercise recent (as of October 2011) versions of Apache, Nginx, Lighttpd, G-WAN, and IIS — a list that includes the most popular web servers as well as web servers … Continue reading »
Load Testing Back to Basics: Avoiding the KeepAliveTimeout Race Condition
You’ve recorded your test case, configured your datasets, and run your replays. You start up the load test and … you see numerous errors like this:
“The connection with the server was unexpectedly closed before starting the response.”
What’s going on? Well, one common reason for this error is a connection-related race condition between Load Tester and the web server due to the server’s configured persistent connection timeout.
Persistent connections are an HTTP mechanism for minimizing network connection overhead between the browser and the web server. If the client has the Connection request header set to Keep-Alive, and the server responds with the … Continue reading »
Load Testing with IE 8.0, Firefox 3.5
The performance improvements in the latest browsers (Internet Explorer 8.0 and Firefox 3.5) have been eagerly awaited for many months…though they come at a price.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree in Computer and Electrical Engineering at Purdue University, he found himself writing software for industrial control systems. His first foray into testing software resulted in an innovative control system for testing lubricants in automotive engines. The Internet grabbed his attention and he became one of the first Sun Certified Java … Continue reading »
Measuring the Performance Effects of mod_deflate in Apache 2.2
Enabling mod_deflate can reduce the bandwidth usage on a particular file by up to 70%, but also reduces the maximum load a server can handle and may actually reduce site performance if the site compresses large dynamic files. Read the full report for a complete analysis.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree in Computer and Electrical Engineering at Purdue University, he found himself writing software for industrial control systems. His first foray into testing software resulted in an innovative control system … Continue reading »
Open Source PHP Accelerator Increases Performance 2.8 Times
The latest installment in our PHP performance series takes a look at the open source APC module, which is described this way: “APC is a free, open, and robust framework for caching and optimizing PHP intermediate code.” The results were dramatic, as the module increased the user capacity of the reference PHP application by 2.8 times.
Read The Article
Michael CzeiszpergerFounder of Web Performance, Inc
B.S. Electrical & Computer Engineering
The Ohio State University
LinkedIn Profile
www.webperformance.com