With all the customers running Tideways on their Magento, Oxid or Shopware shops I was interested in how in the aggregated average, those shops usually perform on Black Friday compared to the 8 weeks before and the weeks after leading up to Christmas.
A lot of e-commerce shops have either large Black Friday, Cyber Monday or week long christmas campaigns, which can increase the traffic to the shops significantly. Both with and without caching a lot of this traffic will directly slow down PHP application servers because of the additional requests that compete for the same amount of Server, CPU & Memory resources.
To quantify this effect across all our customers we looked at the aggregated, anonymized historical data of all our customers with either a Magento, Oxid or Shopware shop for the years 2016 and 2017. We only looked at shops that had at least 100.000 requests on Black Friday and at least 14 days of data reported before and after that date. The sample size of this study is 168.
What change in requests can you expect on Black Friday?
On average across all 168 applications we saw an increase in the number of PHP backend requests (behind any potential caches) of 66% on Black Friday. The maximum increase was 874%.
30 of the 168 shops did not run specific Black Friday campaigns as their requests were equal or lower than each day before. Shops without Black Friday campaigns seem to have a dip in requests and then recover immediately in the time afterwards. Another interpretation that we cannot see from our data is that their shops were not available 100% on Black Friday due to too much traffic.
In the days after Black Friday the increase in PHP requests compared to October and November still amounted to 20% on average across all 168 shops with the highest increase being 287%.
How does increased BlackFriday traffic affect performance?
From the Tideways perspective the changes in requests are not the most interesting part that we can study from our historical data, but we are interested in subsequent performance changes.
Of our 168 applications we found that 49 were optimized by their operators in the time before Black Friday or received additional computing resources (we can't see that from our data), leading to a better performance on Black Friday and afterwards.
If we look at all the shops that haven't optimized their performance or scaled computing resources before Black Friday sufficiently, then we can see that their 95% percentile performance increases by around 29% on average. The shops that got hit hardest were bogged down by 95% percentile increases of 500% and more, sometimes leading to response times way above 10 seconds.
Even if your shop uses caching for most of your frontend, getting hit by these performance increases means that the basket and checkout process is much slower than usually and can lead to aborted carts and customer that leave your shop because of slowness.
The relationship of slow performance with increased page abandonment has been studied by Google, Amazon and many other major e-commerce players. They leave no doubt that it is important to get in front of your shop performance when planning small and large Black Friday, Cyber Monday and Christmas campaigns.
And if you know that your shop can't handle a large increase in traffic, then maybe optimize your campaigns to be smaller and more spread across christmas season.
Ready for Black Friday with insights from Tideways Profiler
If you run a Magento, Spryker, Oxid, Shopware or any other PHP based webshop, then Tideways can help you find out about the endpoints with the highest impact on performance, bottlenecks, slow SQL queries and help you find optimizations to get ready for Black Friday and Christmas season.
This includes the personalized Black Friday preparation report that we will sent you in the aftermath of Christmas 2018 and again next year in August.