Anybody who has used internet or visited a website must have encountered the term ‘website crash’. What exactly it is, have you ever explored? In a simple language, it is the inability of a website or a webservice to withstand load. The traffic surge puts pressure on the website server and it may fail to respond to all commands and queries received. There can be other reasons, too, like bandwidth issues, etc.
In this post, we intend to walk you through:
1. What is load testing?
2. How to do load tests
· Creating and performing load tests
· Other important steps in load testing
3. Load testing strategies
So, let’s begin!
a. What is load testing?
Load testing is nothing but performance testing. It involves testing how the web service or API will work in a given set of conditions. Load testing services create simulated environments to find how the web service will work in response to various types of external and internal factors.
b. How to do load tests?
Load tests require creating different types of loads that may impact functions first. The load testing services have a full-blown repertoire of loads to create. Not only do they design load testing strategies of various kinds, they also offer the intelligence of validating the tests done to their clients. The process is demarcated into various parts, such as:
· Create a new load test
Load testing services employ automated tools to do performance tests. The tool comes with a navigation panel. Common steps involved in creating a new load test are:
a. Go to Navigator Panel
b. Right click on the test instance or case
c. Select ‘New Load Test.’
d. Enter the load test name in subsequent dialog box, for example, SampleLoadTest
This opens the LoadTest editor. Now you are all set to configure and perform the created test.
· Perform the load test
Performing the load test involves following steps:
· Creating a dedicated test environment for starting the load test
· Determine load test scenarios, by preparing following criteria:
o Prepare data report transaction-wise
o Predicted number of user at any instance
o Types of connections plausibly used by people
o Types of operating systems and browsers users are likely to use
o Web, application and DB server configurations
· Execute tests scenarios in various combinations, monitor and collect various metrics
· Result analysis and recommendations
· Apply all system fine-tuning procedures
· Repeat the performance test on all chosen grounds
Best load testing strategies
Load testing services adopt different strategies to test web service performance. Load testing is done in simulated conditions. However, there are some strategies that can help perform load tests as realistically as possible. These strategies are:
a. Adding more virtual users: In real conditions, the web service is utilized by several virtual users simultaneously. The load testing services may create bottlenecking conditions at the login point. And, keep adding the users simultaneously.
b. Adding different use instances:The real working capacity of the web service can be checked by exposing it to various use instances. Load testing experts can employ user data in different combinations in the web service fields. However, the focus is to be on testing service by putting different information each time. Playing back the results for the same person using various information fields interfere with the sanctity of the result.
c. Switch from simulated to real browsers: It is nothing but leveraging the virtual users on real browsers. The process involves:
· Understanding and assessing how the web service will work in different devices and browsers.
· The performance check on different bandwidths plausibly used by the web service users.
· Since the users may spend different times on various pages, the page performance comprising load time, think time, etc. can be found out.
d. Set the load duration:All users don’t access the web service concurrently. Some may have just logged in, others may be at the checkout page, and so on. The users enter their scenario, complete it, and also, the load is maintained for that duration. The tester may have run the scenario for ten minutes for a 2 min long instance. So, experience of 5 concurrent users can be assessed by using load duration time of 10 mins.
How to analyze the load test results
Load means how well a system or application can handle multiple requests coming from concurrent users. The load test results are analyzed based on the following parameters:
- Page Load Time
- Request and response throughput
- Response load time
- Errors and warnings
a. Page load time: A short page load time means better user experience and engagement. The web service does not take more than a second to load. Thus, the web service may enter an SLA with the developer where they agree upon having a page load time. There is a challenge of bottleneck to combat too. It arises when the page load time differs due to the nature of content.
b. Request and response throughput: It is dependent on the amount of data the web service is required to handle. Bandwidth reaches a plateau after a certain point of data handling. The point of reaching the highest use is mostly due to firewalls. Load test allows to find what setting will be required to ensure that the bandwidth does not reach the maximum use.
c. Response load time: This analysis-worthy point helps understand the reason why any page behaves the way it does. The response load time helps find which activity or instance is consuming the most time or resource. All the tests done in load test can be integrated into various kinds of web service performance monitoring tools.
d. Errors and Warnings: This point of analyzing loads gives an overview of what kind of errors occur on any web service’s page and at what instance. Load testing services may make a list of all the errors and warnings that occur. Further, the analysis is done to find how the errors occur and change when the load intensifies or cools down.
e. Hosts: The current ecosystem of web service comprises ads and analytics servers, content delivery networks, social media and syndicated content, multiple hosts are put to use. The hosts serving the web service may be a source of lag due to the response times involved in processing requests. All those lags need to be understood to take appropriate action. When any host is found painfully slow, the factors and the remedies need to be outlined.
Important tips for load testing
Online retail faces the most load on Black Friday. It is the day after Thanksgiving and is no less than an acid test for web services or applications. To manage the unprecedented situations like this day, load testing is essential. Important tips are:
a. Test the load well in advance
b. Test the web service’s full stack
c. Monitor the backend results
d. Gauge user experience
e. Test in real life scenarios too, after testing it in simulated conditions.
The load is a challenge as well as the opportunity. Makers of web service find the load handy in understanding the design and functionality requirements, and any other changes it requires. They can do scaling up or down of resources by taking cues from the results of load tests.