Direct jump to multi-user tests; Test results not validated; Unknown workload details It seems like on every new project, there is a need to educate members of the project team on the difference between concurrent users and simultaneous users as it applies to load testing applications. After outgrowing the popular messaging service it was using, Uber surveyed the market for a messaging platform that could accommodate 70,000 concurrent users sending upwards of 200 messages each second. It is also true that good tools that can test thousands of virtual users cost an arm and a leg. Quick Steps Overview 1. Usually, people get confused with concurrent users and simultaneous users as these both are used interchangeably, but in performance testing these two terms have different meanings. How to extend lines to Bounding Box in QGIS? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Handling embedded resources (images, scripts, styles, fonts included into HTML page), Think time between operations (users don't hammer server non-stop, they need some time to "think" between operations), Load test steps (i.e. Currently, I have all the test runs automated so that every night, a 10,000 concurrent user test is initiated that runs for approximately 12 hours. But can you simulate a larger user load with a small set of virtual users? In load testing, the number of concurrent users is a pretty standard measure of throughput, and generally, it means the number of users that are accessing an application at any one point in time. Key takeaways. How do you run a test suite from VS Code? Each of the users would be performing different actions like one doing login , other viewing the reports, etc. Handling jmeter concurrent users with if statements. Q. In Europe, can I refuse to use Gsuite / Office365 at work? The answer is “may be” — though most likely yes! If you could do that, you would buy a handful of concurrent users — like 500. Ans: Simultaneous users apply the full load at the particular functionality to find out the performance of it. It helps in identifying and measuring the problems in system parameters such as response time, throughput, deadlock occurrence or any other issues related simultaneously. How is the Ogre's greatclub damage constructed in Pathfinder? What is concurrent user hits in load testing? Most of you probably know the term Concurrent User. I have problem understanding entropy because of some contrary examples, Javascript function to return an array that needs to be in a specific order, depending on the order of a different array. These vusers performing the same task at the same time are called S imultaneous vusers. Session information (total number of sessions, average length of the sessions) is helpful in … 'Also JMeter concurrent threads are not "concurrent users" as real-life people do pauses between actions on web pages. fly wheels)? This article will describe the steps you need to take to easily run a load test with 50k concurrent users test (as well as bigger tests with up to 2 million users). In Microfocus LoadRunner this is represented by a concept called rendezvous. "Hourly Sessions x Average Session Duration (in seconds) / 3,600" is the formula we recommend to get started It’s always good to take the guesswork out of your load testing and test … What are the earliest inventions to store and release energy (e.g. Simultaneous = users executing the same code at the exact same time. Making statements based on opinion; back them up with references or personal experience. What is the difference between load tests and performance tests? Why server CPU usage reaches to 100% with only 25 concurrent users? And even on Flood, we use it because it's a really good rule of thumb. Determine concurrent users for a mobile app performance testing. That means a single user will execute (60/2) = 30 transactions in an hour. Transactions highlighted in Green are completed by the user and in yellow are yet to be started which also remains the same for all users. Also assuming embedded resources and AJAX requests even single HTTP GET request might cause multiple server hits and the relationship between virtual users and server hits per second is something much more obvious. Concurrent user testing measures how long it takes the server to respond to a specified number of simultaneous requests. If you don't set any pauses in your tests then 20 concurrent threads will stand for something like 200-250 concurrent users.' On the other hand simultaneous vusers is more to do with rendezvous points. VB Script to delete a set of files based on file extension, Standard deviation and its importance in performance testing, lr_read_file Loadrunner Function to read the content of a text file, SaveOffset attribute in web_reg_save_param, web_concurrent_start & web_concurrent_end, Loadrunner scripting for Rest API services - web_custom_request, Parameterization in TruClient Protocol Loadrunner - JavaScript Based (Method 2 - LR.getParam), C Program to write loadrunner parameter output to text file, Pacing Calculation in Loadrunner - Performance Testing, Understanding the relationship between hits per second & throughput in performance testing. Knowing the correct figures of simultaneous & concurrent users is very vital in order to perform performance testing of an application. Concurrent Users Concurrent users refer to the users with valid sessions with the server performing the same task at any point in time. "Everyone push the enter button in 3, 2, 1, Now!" Whenever someone asks us how many concurrent users they “should” use in a test to understand their performance baseline and prepare for a big wave of traffic, we like to follow a … What are the common mistakes done in Performance Testing? When configuring a test plan for our clients we want to establish a realistic number of concurrent users, in other words, the number of users actually in the system, actively using the application at a given time. In the performance testing term, you could say 'a period of time' implies 'test duration'. How can I randomly replace only a few words (not all) in Microsoft Word? The idea behind concurrent user testing is to identify the response time of a website for a specified number of simultaneous users making requests to a website. Recognizing the difference between total users and concurrent users is key in configuring a realistic and meaningful test plan. I see the explanations are contradictory in the internet. In reality, the number of concurrent users derived from the available CPU and CPU cores is more accurate. "Concurrent users" in performance testing - limitations. Join Stack Overflow to learn, share knowledge, and build your career. Most probably they have the same meaning. Why do we use approximate in the present and estimated in the past? The more realistic your simulation, the more likely you'll catch bottlenecks that lead to a bad user experience. Do GFCI outlets require more than standard box volume? Why do "checked exceptions", i.e., "value-or-error return values", work well in Rust and Go but not in Java? Simultaneous users are the users who have a valid session in the server. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Interesting articles that improve the performance of performance testing... Understanding the difference between the Concurrent and Simultaneous users is very much important in generating the type of user load for performance testing. So to reach 10K transactions, you’d need: (10k/30) = 333 users. Stack Overflow for Teams is a private, secure spot for you and The goal of load testing is to find problems before they impact users. While many variables affect accuracy, the number of concurrent virtual users is one of the most important. How does SQL Server process DELETE WHERE EXISTS (SELECT 1 FROM TABLE)? Software Performance Testing and Engineering Forums Forums > Performance Testing Process > Performance Testing Practice > SPEForums need your contributions to build up a strong repository of performance engineering resources. Concurrent user licensing allows firms to purchase computer systems and software at a lower cost because the maximum number of concurrent users expected to use the system or software at any given time (those users all logged in together) is only a portion of the total system users employed at … If you know the exact meaning of simultaneous and concurrent words then you can easily correlate them with performance testing term. In load testing, without any time difference when multiple users hit on the same event of an application under the load test is called a concurrent user hit. Transactions highlighted in Green are completed by the user and in yellow are yet to be started which also differs from user to user. Concurrent user testing is also called simultaneous user testing. Once done you can set up a Load Test with anticipated amount of concurrent users, let say 10 to determine performance baseline and execute this short smaller test periodically and in automated manner (i.e. Translating requests per second into concurrent users. Given certain virtual users concurrency some of the "load test steps" can be (and given more or less high load will be) simultaneous. your coworkers to find and share information. To understand the difference, I would suggest to know the meaning of these two words. We could see that all the users are in the same search cart transaction denoted by x mark. By "as close as possible" I mean all real user's stuff, i.e. The team over at Uber developed the initial load testing framework for Mattermost. Hence, you would have noticed this already. Also, if you calculate the average concurrent sessions between 8 PM and 9 PM on that day when there are more users, the average concurrent sessions are 41.4808. In the context of load and performance testing, this metric is often claimed the measure of all things, accompanied by the mentioning of astronomically high numbers we can’t really verify and that sometimes are simply used as sales argument for overpriced software products. for a span of time. rev 2021.1.11.38289, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide, Difference between Simultaneous and Concurrent users, the relationship between virtual users and server hits per second, Podcast 302: Programming in PowerPoint can teach you a few things. Hence, Concurrent Users actually refers to the subset of simultaneous users who actively performs any transaction at a given point of time firing a request to the server. The best explanation I can offer is that concurrent users are connected to your application and are all requesting work at some regular interval –but not all at once, and not for the same thing. Difference between Concurrent & Simultaneous users... Below is the table of 5 users working in an e-commerce application. Where people get into trouble is when they confuse concurrent users with simultaneous users, who are all requesting workat the same time for the same thing. Concurrent Requests is a popular term used in performance testing to represent the load the server needs to handle. Asking for help, clarification, or responding to other answers. Yes, I am in an argument with a client about this fact. make it as a part of your continuous integration pipeline) - this way you will get confidence that the new functionality or bug fixes will not cause performance degradation. Simultaneous testing is a type of testing that is performed to identify the defects in a software, system and application when multiple users login to the respective application. Loadrunner : How to pass a correct correlation value to the request when the ordinal value and total count of correlated parameter is inconsistent? In the context of load and performance testing, this metric is often claimed the measure of all things, accompanied by the mentioning of astronomically high numbers we can’t really verify and that sometimes are simply used as sales argument for overpriced software products. Hi there, We are using JMETER 3.2 to do a series of performance tests (stress testing) with a large number of concurrent users (3000, 4000). simultaneous = same action, same time. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. These are the 2 terms which is often used in Performance Testing. Why would someone get a credit card with an annual fee? Why is there no Vice Presidential line of succession? This is not to say that session information is useless. These performance tests are very basic tests where there is only single HTTP request (per user). Hence for a web site, the number of simultaneous users would be always greater than the concurrent users.For example , a banking web site has the workload of about 30000 simultaneous users & 5000 concurrent users. Most of you probably know the term Concurrent User. Concurrent users are the users who have a valid session in the server & they are performing the … To learn more, see our tips on writing great answers. Concurrent Users: The word concurrent is used only for the events that occur over a period of time i.e. How do airplanes maintain separation over large bodies of water? We could see that each user is in a different transaction denoted by x mark. First atomic-powered transportation in science fiction. On a weekend, the automated test run, also tests using 10,000 concurrent users, but runs for approximaely 60 hours. Great graduate courses that went online recently. Transactions highlighted in Green are completed by the user … We could see that each user is in a different transaction denoted by x mark. Of course, this calculation will only help you to estimate the number of concurrent users for a general load on a … Many companies mistakenly take the total number of sessions and assume it to be the number of concurrent users needed for a load test. tl;dr — This post is about using Google Analytics to determine how many concurrent users to specify in your load tests. Performance Testing, Simultaneous User, Concurrent Users, Difference between Simultaneous Users and Concurrent Users, Performance Testing Basics, Simultaneous Vs Concurrent In performance testing there should be only one term: virtual user which must represent real user, that's it. Example: Tatkal reservation at IRCTC site Also assuming embedded resources and AJAX requests even single HTTP GET request might cause multiple server hits and the relationship between virtual users and server hits per second is something much more obvious. for a span of time. Good or Bad? difference between Simultaneous & Concurrent users. It is usually calculated with a short time period of 1 to 30 minutes. While designing your load test, look at the right numbers and right time frames. Below is the table of 5 users working in an e-commerce application. Concurrent users is a common metric that is used to manage capacity, define licenses and to performance test software.The following are illustrative examples of concurrent users. This is almost 2x than the monthly average concurrent users. Well-behaved load test has to represent real user as close as possible, otherwise it will not make a lot of sense to run such a test. open login page, perform login, navigate somewhere, etc.). They are thinking 50 Threads = 50 Users. A load of simultaneous user confirms that the particular page or functionality of the application can handle the desired load or not at a time. When we set rendezvous points we instruct the system to wait till a certain no of vusers arrive so that they all can do a particular task simultaneously. 18 What is the use of simultaneous users? Thanks for contributing an answer to Stack Overflow! For HTTP (S) test each Load Injector can handle approximately up to 1000 concurrent HTTP users. How to run web performance test for 200 users in VS 2013? Why? Concurrent = operating in same window of time, but each on an independent set of actions. Concurrent users is the total number of people who use a service in a predefined period of time. For Web page or Web application test each Load Injector can handle approximately up to 25 concurrent users. Performance: A brief history. So, it’s better to go for a solution where there is a large scale testing of million concurrent users at the HTTP level and using real browsers when the required load is not too much. Difference between Concurrent & Simultaneous users in Performance Testing. Concurrent = users on the system using resources. How do I Performance test a 3rd party API which has limitations on number of concurrent users? : Given certain virtual users concurrency some of the "load test steps" can be (and given more or less high load will be) simultaneous. Hence the users which are running under a test plan; irrespective of the activities they are doing; are called as 'Concurrent Users'. In the performance testing term, you would say ‘a period of time’ implies ‘test duration’. Concurrent Users: The word concurrent is used only for the events that occur over a period of time i.e. Loadrunner - Replacing a character in a text file... Best Practices for Loadrunner Vugen scripting. 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