Website Performance Testing / Vulnerability Testing You Can Do Yourself

Performance testing is conducted to ensure the performance of a website and prevent problems such as servers crashing under heavy load once the website goes live.
Vulnerability testing is conducted to detect weaknesses in a website in order to prevent tampering, information leaks, and external attacks that exploit security vulnerabilities.
Here, we will introduce various types of tests designed for different purposes.

This test is conducted to verify whether the website has sufficient display and processing speed when actually viewed, and whether it reaches a level of performance that satisfies users.

This test intentionally generates a large amount of traffic to a website in order to verify what kinds of bugs or issues occur.
It allows you to confirm at what level of traffic errors begin to occur or data corruption happens.

This test temporarily increases the load on a website to verify whether it can withstand the expected peak load conditions.
Its purpose is to measure and quantify how much performance degrades as the load shifts from normal conditions to peak conditions, as well as how many users the system can support.

This test is specifically focused on verifying the maximum number of users that an application managed on a website can support.

This test applies a sustained load to a website over a long period of time to verify whether it can maintain stability.

Performance testing offers a variety of benefits.
It allows you to check response times, the processing capacity limits for concurrent users, which content is causing performance degradation, and what kind of impact unexpected loads may have.
These results serve as indicators for determining what kinds of countermeasures are necessary.
For example, if it becomes clear that the server cannot handle a large amount of traffic, you may need to consider improving server performance.
It can also serve as a guideline for planning future server expansion and redundancy in anticipation of increased numbers of users.

k6

k6 is a load testing tool provided by the Swedish company k6 (formerly Load Impact). (Free to use up to 5 times per month.)
It is an open-source load testing tool that allows you to write test scenarios in JavaScript and perform load testing.
With the paid version, you can also increase the number of concurrent connections.

Apache JMeter

Apache JMeter is a free performance testing tool and an open-source application that can be operated through a GUI.
It allows testing under various scenarios. For example, you can finely configure response times, loop counts, user numbers, and more, making it very convenient for testing websites according to their specific needs.

There are many free performance testing services available on the web.
Be sure to look for a tool that best matches the characteristics of the website you want to test.

In addition to performance testing, vulnerability testing is another important measure to consider.
Websites are constantly exposed to threats from malicious attacks.
Conducting tests is extremely important in order to reduce risks such as personal information leaks, tampering, and operational disruptions.
※ Before conducting tests...
If you are using a rental server or similar service, it is a good idea to inform the server administrator about the test in advance.

OWASP ZAP

This is an open-source tool that scans websites for vulnerabilities free of charge.
It also supports Japanese, making it relatively easy for beginners to use.
However, if you are using a shared rental server rather than your own environment, the tool may insert test records into the database or send a large number of requests to dynamic content such as forms. In some cases, the server administrator may mistake this for an actual attack and change passwords or take other security measures. Therefore, it is best to notify the system administrator in advance before performing the test.

※ Caution ※
Vulnerability testing should only be performed on websites for which you have permission to test or websites that you personally manage.

No matter how excellent a website may be, it would be a waste if it could not withstand a large amount of traffic.
After all, you want as many people as possible to access your site.
Performance testing may sound a little difficult, but it’s definitely worth taking on the challenge in order to build a robust website.
If you would like to learn more about vulnerabilities and security knowledge, a good starting point is to read the official IPA documentation, which explains the fundamentals of web security.

Reference: IPA “How to Build Secure Websites”

IPA (Information-technology Promotion Agency, Japan) “How to Build Secure Websites”