The Ultimate Black Friday Technical Checklist: Prepare your infrastructure for Black Friday

Imagine this: a big celebrity mentions one of your products right before Black Friday as if you didn’t already have enough on your plate that day. Are you fully equipped to handle the extra traffic to your website? 

The good news for most eCommerce websites after such an unpredictable time is that more shoppers will be making online purchases this year on Black Friday. eCommerce sites are in a good spot, especially when 47% of shoppers are still unsure about in-store shopping, and 56% of them will continue to shop online even post-pandemic. 

But do you have all of the technical aspects taken care of so your site doesn’t crash? Remember, visitors won’t stick around for long if your page doesn’t load, and even one second makes a huge difference. In fact, a one-second delay reduces customer satisfaction by 16%! See below how you can avoid that.   

One of the first steps you’ll want to take is to analyze your business objectives, see what products begin to trend leading up to Black Friday, and make sure you’re stocking the right products. If you’re finding that it’s not easy to get shipments out on time or to compete with other online businesses, it’s time to consider automation. 

This is where Environment as a Service (EaaS) can really come in handy, an all-in-one application environment. You’ll get massive increases in development speed, along with reduced cloud costs of up to 60%. Not just that, but an EaaS solution supports faster innovation and will eliminate any environment bottlenecks you may be experiencing. You have an amazing testing environment that cuts down on costs, saves your development team time, and improves product quality. 

You’ll be able to speed up everything from customer service to inventory and shipping. The only thing you’ll have to worry about is more profits! If automation is something you’ve already perfected, then check out the next steps you can take to prepare your infrastructure.

The next step is to do an infrastructure discovery analysis – map out your servers, their current size, components, projects, and applications. Additionally, you can also look at the associated costs to get an idea of how much money you’ll need to spend to prepare your technical infrastructure for Black Friday.

Once you’ve drawn a diagram, it’s time to identify possible bottlenecks, meaning the components that might fail due to the sudden increase in traffic. 

A stress test is an analysis conducted under unfavorable scenarios that helps you assess whether your IT infrastructure has sufficient mechanisms in place to withstand the impact of adverse developments. Simply put, a test aimed at all production infrastructure points.

Ok, so why should you perform it? Because you need to know how much your infrastructure can handle and how much you need to scale it to accommodate the Black Friday traffic. 

Note: you’ll never want to stress test on your live infrastructure. Instead, you need to recreate your current infrastructure in the cloud and apply your tests on that instead. 

Checklist

✅ Operating system (limits, IOPS, resources)

✅ Cloud resources (disk sizes, database, web servers, PHP, FPM)

✅ Configurations (nginx, apache, memecache, PHP, MySQL, stand-by processes)

✅ Anything else you might be using

To make sure you’re replicating the situation as accurately as possible, try to mimic your users’ behavior as best you can. To do that you can: 

To perform a stress test, you need to:

Keep in mind that you should try to mimic your users’ behavior as best as possible, otherwise your stress test will not be accurate.

If you’ve done everything correctly, you should see that, under certain conditions, various components of your infrastructure will start to fail. This is when tuning comes into place.

The first component you should look at and tune is the operating system:

Once you figure this out, you can start looking at your cloud components. 

One thing you should keep in mind, though, is that you need to perform a new stress test after every change. If your infrastructure passes the stress test, you can keep the changes. If not, you should revert to the last working instance and start tuning again. 

A few optimizations you can make at the resource level are:

Don’t use autoscaling! During stress tests, you want to figure out just how much your infrastructure can handle before you need to scale. Relying solely on autoscaling on Black Friday might not be reliable enough.  

Once you’ve optimized your resource usage, you need to move on to optimizing your infrastructure’s configuration. This includes all the technologies you use, like nginx, apache, memecache, PHP, etc.

First is the configuration of your web server, PHP, and MySQL. Take a look at your web servers – more specifically, at the number of workers (PHP, FPM), stand-by processes, idle workers, and connections (MySQL). Then, repeat these steps for your database server.

Then comes the configuration of your application. You need to take a look at your MySQL queries and see if any of them are lagging. If yes, you should enable slow-log and see what causes the delay and eliminate the cause. 

Once you’ve finished optimizing your infrastructure at the resources, configuration, and application levels, you should perform another stress test to see if all changes are compatible with one another. Ideally, your infrastructure should pass this test, otherwise, you’ll need to take each component one by one and repeat the process.

While performing this “roundup” stress test, there are 2 things you should keep in mind:

As a general note, if a web server can handle 100 users per second, this doesn’t mean that it can manage a sudden increase from 0 users to 100 users. It’s often precisely because of this that eCommerce websites crash.

You’ve mapped out your infrastructure, identified possible bottlenecks, and came up with solutions for each of them. Now it’s time to take each component one by one and see how you can scale it in case it needs to handle a bigger load than you previously thought.

For your database, you can consider a master-slave or a master-master architecture. 

In a master-slave architecture, you need to decide whether your application will be able to read from a slave (you scale reading). In a master-master architecture, on the other hand, you’ll scale both reading and writing.

The scaling of your web server is fairly easy – you just need to enable autoscaling. What you need to keep in mind is a minimum number of instances and configuring your autoscaling for rapid scaling (meaning, instead of scaling with one instance, at a time, scale with two or more). 

You also need to test how fast new machines are added to your infrastructure. The longer it takes to add new servers that can share the load, the higher the chances your website will crash. Depending on this speed, you’ll determine how many new servers you’ll need (scale-up number).

Even after following the previous steps, your IT infrastructure is not 100% foolproof. So take a step back, look at the whole picture, and try to identify what could go wrong – which component is most likely to fail?

Brainstorm with your team and try to come up with solutions. If you don’t have solutions available (for example, you can’t prepare a backup plan for when your cloud provider is experiencing an outage), the least you can do is prepare your other departments (like marketing or support) to respond in case the worst-case scenario becomes a reality. 

Tip 1: You need to choose the right stress test tool for you. A tool that is not able to emulate the scenario you expect on Black Friday, is a tool that you can’t rely on. 

Tip 2: Always personalize your stress tests. Different websites have different user behaviors – maybe your users browse for a long time before they add products to their cart and check out, in which case you need to optimize your website for high traffic. 

Or maybe they add all the products they want to their cart the night before, and on Black Friday they just log in and pay – in which case you need to optimize your database. 

Tip 3: Use an advanced monitoring system capable of assessing each component’s performance in real-time, and log aggregation to catch all errors (so you can fix them later).

Tip 4: Write down your results after each stress test, associate them with different configurations, and see what issues are solved and what you still need to work on.

As we’ve mentioned at the beginning of the article, performing an infrastructure discovery analysis helps you determine how much you’re spending on your current infrastructure. After figuring out how much you need to scale it, you’ll be able to estimate your Black Friday scaling budget.

You’ve spent so much time and money preparing for this day, it would be a waste if everything went down the drain because of a DDoS attack. Make sure that you also install and configure a Web Application Firewall (WAF) – and include it in your stress tests at the application level – as well as a Rate Limiting for your web server.

For a more efficient configuration, you can install these two tools on an external component (like Cloudflare), instead of directly on your web server. 

If you want to make sure nothing takes you by surprise, draft a pre-mortem – try to think of every possible scenario and come up with a solution. Granted, some issues are completely out of your control, but at least you’ll know about them beforehand. 

Follow the above-mentioned technical checklist that will help you prepare your website for Black Friday. 

In case you’d like a specialized team to help you with your infrastructure, check out how Bunnyshell helps eCommerce websites to prepare for Black Friday.