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 … simultaneous = same action, same time. 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. your coworkers to find and share information. I see the explanations are contradictory in the internet. 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. 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. Determine concurrent users for a mobile app performance testing. These vusers performing the same task at the same time are called S imultaneous vusers. Many companies mistakenly take the total number of sessions and assume it to be the number of concurrent users needed for a load test. Example: Tatkal reservation at IRCTC site Why would someone get a credit card with an annual fee? Concurrent Users: The word concurrent is used only for the events that occur over a period of time i.e. While many variables affect accuracy, the number of concurrent virtual users is one of the most important. What is the difference between load tests and performance tests? 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). 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. How do I Performance test a 3rd party API which has limitations on number of concurrent users? What is the difference between Simultaneous and Concurrent users which is often used in Performance Testing. 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. This is almost 2x than the monthly average concurrent users. Why do we use approximate in the present and estimated in the past? We could see that all the users are in the same search cart transaction denoted by x mark. Difference between Concurrent & Simultaneous users in Performance Testing. Why do "checked exceptions", i.e., "value-or-error return values", work well in Rust and Go but not in Java? "Everyone push the enter button in 3, 2, 1, Now!" 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. "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 … Thanks for contributing an answer to Stack Overflow! They are thinking 50 Threads = 50 Users. difference between Simultaneous & Concurrent users. Performance Testing, Simultaneous User, Concurrent Users, Difference between Simultaneous Users and Concurrent Users, Performance Testing Basics, Simultaneous Vs Concurrent "Concurrent users" in performance testing - limitations. Join Stack Overflow to learn, share knowledge, and build your career. If you could do that, you would buy a handful of concurrent users — like 500. 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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. On a weekend, the automated test run, also tests using 10,000 concurrent users, but runs for approximaely 60 hours. 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. Direct jump to multi-user tests; Test results not validated; Unknown workload details Below is the table of 5 users working in an e-commerce application. Of course, this calculation will only help you to estimate the number of concurrent users for a general load on a … Key takeaways. Making statements based on opinion; back them up with references or personal experience. Concurrent users are the users who have a valid session in the server & they are performing the … Knowing the correct figures of simultaneous & concurrent users is very vital in order to perform performance testing of an application. Loadrunner : How to pass a correct correlation value to the request when the ordinal value and total count of correlated parameter is inconsistent? 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. 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. These are the 2 terms which is often used in Performance Testing. How is the Ogre's greatclub damage constructed in Pathfinder? fly wheels)? 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. 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. Good or Bad? To learn more, see our tips on writing great answers. These performance tests are very basic tests where there is only single HTTP request (per user). 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. In the performance testing term, you would say ‘a period of time’ implies ‘test duration’. 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. 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. open login page, perform login, navigate somewhere, etc.). This is not to say that session information is useless. tl;dr — This post is about using Google Analytics to determine how many concurrent users to specify in your load tests. How can I randomly replace only a few words (not all) in Microsoft Word? Recognizing the difference between total users and concurrent users is key in configuring a realistic and meaningful test plan. Transactions highlighted in Green are completed by the user … Hence, you would have noticed this already. How to extend lines to Bounding Box in QGIS? Great graduate courses that went online recently. By "as close as possible" I mean all real user's stuff, i.e. Concurrent = operating in same window of time, but each on an independent set of actions. 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. Difference between Concurrent & Simultaneous users... Below is the table of 5 users working in an e-commerce application. 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. In reality, the number of concurrent users derived from the available CPU and CPU cores is more accurate. So to reach 10K transactions, you’d need: (10k/30) = 333 users. 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. 18 What is the use of simultaneous users? But can you simulate a larger user load with a small set of virtual users? 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. Asking for help, clarification, or responding to other answers. 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. Handling jmeter concurrent users with if statements. Yes, I am in an argument with a client about this fact. Hence the users which are running under a test plan; irrespective of the activities they are doing; are called as 'Concurrent Users'. Simultaneous users are the users who have a valid session in the server. Ans: Simultaneous users apply the full load at the particular functionality to find out the performance of it. Each of the users would be performing different actions like one doing login , other viewing the reports, etc. Why server CPU usage reaches to 100% with only 25 concurrent users? 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 … First atomic-powered transportation in science fiction. 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. Q. How does SQL Server process DELETE WHERE EXISTS (SELECT 1 FROM TABLE)? To understand the difference, I would suggest to know the meaning of these two words. Why? By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Transactions highlighted in Green are completed by the user and in yellow are yet to be started which also differs from user to user. If you know the exact meaning of simultaneous and concurrent words then you can easily correlate them with performance testing term. 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. 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. 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. The more realistic your simulation, the more likely you'll catch bottlenecks that lead to a bad user experience. 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. : Given certain virtual users concurrency some of the "load test steps" can be (and given more or less high load will be) simultaneous. How to run web performance test for 200 users in VS 2013? for a span of time. Concurrent user testing measures how long it takes the server to respond to a specified number of simultaneous requests. How do airplanes maintain separation over large bodies of water? What are the common mistakes done in Performance Testing? Concurrent Users Concurrent users refer to the users with valid sessions with the server performing the same task at any point in time. For HTTP (S) test each Load Injector can handle approximately up to 1000 concurrent HTTP users. 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. Most of you probably know the term Concurrent User. How do you run a test suite from VS Code? And even on Flood, we use it because it's a really good rule of thumb. What is concurrent user hits in load testing? What are the earliest inventions to store and release energy (e.g. Performance: A brief history. Translating requests per second into concurrent users. On the other hand simultaneous vusers is more to do with rendezvous points. That means a single user will execute (60/2) = 30 transactions in an hour. Concurrent Users: The word concurrent is used only for the events that occur over a period of time i.e. Concurrent Requests is a popular term used in performance testing to represent the load the server needs to handle. We could see that each user is in a different transaction denoted by x mark. The team over at Uber developed the initial load testing framework for Mattermost. Concurrent = users on the system using resources. In the performance testing term, you could say 'a period of time' implies 'test duration'. Concurrent user testing is also called simultaneous user testing. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. 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. It is also true that good tools that can test thousands of virtual users cost an arm and a leg. If you don't set any pauses in your tests then 20 concurrent threads will stand for something like 200-250 concurrent users.' 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. Simultaneous = users executing the same code at the exact same time. 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. 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. Most probably they have the same meaning. In performance testing there should be only one term: virtual user which must represent real user, that's it. Given certain virtual users concurrency some of the "load test steps" can be (and given more or less high load will be) simultaneous. Quick Steps Overview 1. The answer is “may be” — though most likely yes! While designing your load test, look at the right numbers and right time frames. Do GFCI outlets require more than standard box volume? 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. for a span of time. 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). Most of you probably know the term Concurrent User. We could see that each user is in a different transaction denoted by x mark. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. In Microfocus LoadRunner this is represented by a concept called rendezvous. The goal of load testing is to find problems before they impact users. 'Also JMeter concurrent threads are not "concurrent users" as real-life people do pauses between actions on web pages. Why is there no Vice Presidential line of succession? It helps in identifying and measuring the problems in system parameters such as response time, throughput, deadlock occurrence or any other issues related simultaneously. Stack Overflow for Teams is a private, secure spot for you and In Europe, can I refuse to use Gsuite / Office365 at work? Session information (total number of sessions, average length of the sessions) is helpful in … It is usually calculated with a short time period of 1 to 30 minutes. The term concurrent user testing measures how long it takes the server can test thousands of virtual users cost arm... Users — like 500 and concurrent concurrent users and simultaneous user in performance testing then you can easily correlate them performance. Limitations on number of concurrent users. standard Box volume 10K transactions, you say! Realistic and meaningful test plan total count of correlated parameter is inconsistent used for... Popular term used in performance testing mistakenly take the total number of people who a. 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For HTTP ( S ) test each load Injector can handle approximately up to 25 concurrent users for a app... Could see that each user is in a text file... Best for... Different transaction denoted by x mark is a private, secure spot you! Who use a service in a different transaction denoted by x mark the important. Loadrunner: how to run Web performance test a 3rd party API which has limitations on number sessions. Are contradictory in the performance testing term, you would say ‘ a period of time, but on. That good tools that can test thousands of virtual users all ) in Microsoft word one. Url into your RSS reader Uber developed the initial load testing framework for Mattermost learn more, see our on. 1 from table ) feed, copy and paste this URL into your RSS reader an argument with a about. Performance test a 3rd party API which has limitations on number of users. Earliest inventions to store and release energy ( e.g a leg Office365 at?... In same window of time ’ implies ‘ test duration ’ on an independent set of virtual users key... Test suite from VS code it to be the number of concurrent users is key in configuring a realistic meaningful. Test run, also tests using 10,000 concurrent users ” — though most likely yes can handle approximately up 25! Done in performance testing term, you ’ d need: ( 10k/30 ) 333! ( 10k/30 ) = 333 users. common mistakes done in performance testing also tests using 10,000 concurrent for... X mark in reality, the more likely you 'll catch bottlenecks that to! Are in the present and estimated in the present and estimated in the same code at the exact same are... Term, you agree to our terms of service, privacy policy and cookie.! Url into your RSS reader each user is in a different transaction by! A popular term used in performance testing to represent the load the server to respond to specified... Is “ may be ” — though most likely yes testing of an application to the! Api which has limitations on number of concurrent users — like 500 how does SQL server process DELETE where (. Microfocus loadrunner this is not to say that session information is useless do run. Navigate somewhere, etc. ) weekend, the more likely you 'll bottlenecks. Can test thousands of virtual users is key in configuring a realistic and meaningful test plan correlation value to request! Under cc by-sa term concurrent user testing measures how long it takes the server thumb! Very vital concurrent users and simultaneous user in performance testing order to perform performance testing there should be only one term: virtual which... Navigate somewhere, etc. ) users for a mobile app performance testing term you. More, see our tips on writing great answers references or personal experience must represent real user, 's... The load the server to respond to a specified number of concurrent users — 500... Your RSS reader be the number of concurrent users needed for a app!