Blog

Gatling Multiplier Parameter

Published: November 3, 2019

Typically, when load testing a system with Gatling, I create a simulation script which consists of a number of scenarios which are executed simultaneously at different ratios. Execution of the scenarios would look something like this:

setUp(
    BouncerHome.inject(rampUsers(360) during (300 seconds)),
    BrowserCategory.inject(rampUsers(60) during (300 seconds)),
    Searcher.inject(rampUsers(40) during (300 seconds)),
    Uncached404.inject(rampUsers(40) during (300 seconds)),
    UncachedPdp.inject(rampUsers(60) during (300 seconds)),
    PurchaseIntent.inject(rampUsers(10) during (300 seconds))
).protocols(httpProtocol)

I then run the simulation a number of times, gradually increasing the load to identify the breaking point.

For example, after running at the ratios above I might double the load as follows:

setUp(
    BouncerHome.inject(rampUsers(720) during (300 seconds)),
    BrowserCategory.inject(rampUsers(120) during (300 seconds)),
    Searcher.inject(rampUsers(80) during (300 seconds)),
    Uncached404.inject(rampUsers(80) during (300 seconds)),
    UncachedPdp.inject(rampUsers(120) during (300 seconds)),
    PurchaseIntent.inject(rampUsers(20) during (300 seconds))
).protocols(httpProtocol)

Then triple (and so on and so forth).

Expected 404s and Gatling

Published: November 1, 2019

For many websites, for one reason or another (bots?), a not insignificant amount of traffic winds up hitting a 404 page. When load testing a website like this it is important that this traffic is represented for an accurate simulation.

Whitelisting Your Load Test Server IP at Cloudflare

Published: October 31, 2019

Recently I needed to load test an application that sat behind Cloudflare. I tried Google and didn’t find much beyond a thread on the Cloudflare forum’s titled “How to whitelist load testing IPs”.

The thread concludes with sandro suggesting using an “access rule”.

Testing Authorize.NET Credentials with cURL

Published: July 18, 2019

Recently, a client supplied me with Authorize.NET to configure a custom application. When I plugged them in I received the following error:

E00007: User authentication failed due to invalid authentication values.

I needed to get back to them that the credentials weren’t working, but wanted to provide evidence that the error wasn’t due to a coding error in the custom application.

Catalog Permissions Indexer Crashing Magento 2

Published: June 10, 2019

I recently investigated an issue where running a full reindex would cause a Magento 2 site to crash. Of course it’s not best practice to run full reindexes, however, at the same time, it should be possible to do them without crashing the entire website. In this post we’ll explore the issue.

Alert on SSH Login from new IP with OSSEC

Published: May 27, 2019

A useful security alert condition is a login from a new IP address. In this post we’ll explore how to set this up with OSSEC.