Measuring Web Latency in the Browser

We’ll go out on a limb and assume that anyone reading these words is probably familiar with the classic ping command. Depending on which operating system you worship the options might be slightly different, but every variation of this simple tool does the same thing: send an ICMP echo request and wait for a response. How long it takes to get a response from the target, if it gets one at all, is shown to the user. This if often the very first step to diagnosing network connectivity issues; if this doesn’t work, there’s an excellent chance the line is dead.

But in the modern web-centric view of networking, ping might not give us the whole picture. But nature it doesn’t take into account things like DNS lookups, and it certainly doesn’t help you determine what (if any) services the target has available to you. Accordingly, [Liu Zhiyong] has come up with a tool he calls “pingms”, which allows you to check web server latency right from your browser.

Rather than relying on ICMP, pingms performs a more realistic test. It takes the list of targets from the file “targets.js” and connects to each one over HTTP. How does it work? The code [Liu] has come up with will take each target domain name, append a random number to create a gibberish filename, and then calculate how long it takes to get a response when trying to download the file. Obviously it’s going to be getting a 404 response from the web server, but the important thing is simply that it gets the response.

With this data, [Liu] has come up with a simplistic but very slick interface which shows the user the collected data with easy to understand color-coded graphs. As interesting as it is to see how long it takes your favorite web sites or service providers to wake up and start talking, watching the colored bars hop up and down the list to sort themselves is easily our favorite part of pingms.

[Liu] has released pingms under the GPLv3 license, so if you’re looking to utilize the software for your own purposes you just need to provide a list of test targets. If you need to perform low-level diagnostics, check out this handy network tester you can build for cheap.

Listen Up: iPhone Hack Diagnoses HVAC

We all know that guy (or, in some cases, we are that guy) that can listen to a car running and say something like, “Yep. Needs a lifter adjustment.” A startup company named Augury aims to replace that skill with an iPhone app.

Aimed at commercial installations, a technician places a magnetic sensor to the body of the machine in question. The sensor connects to a custom box called an Auguscope that collects vibration and ultrasonic data and forwards it via the iPhone to a back end server for analysis. Moving the sensor can even allow the back end to determine the location of the fault in some cases. The comparison data the back end uses includes reference data on similar machines as well as historical data about the machine in question.

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