Figuring out how many concurrent users you need isn't always straightforward. We will use a semaphore in C# to limit the Maximum number of concurrent users, n, that the system can support at peak load is 5,000. 8 The maximum IP connections are per instance and depend on the instance size: 1,920 per B1/S1/P1V3 instance, 3,968 per B2/S2/P2V3 instance, 8,064 per B3/S3/P3V3 instance. Can it all be handled by one machine? 99 requests per second * 60 seconds * click interval in minutes 2 = 11 880 Max Simultaneous Users in Google Analytics There are a lot of questions you can raise regarding this way of calculating, but from our experience this way of calculating gives fairly precise estimates. If you have the expected number of concurrent users and looking to test if your web server can serve a number of a request, you can use the following command. This post will go over how to make concurrent outgoing HTTP requests on the client side. I'd like to receive emails from TechBeacon and Micro Focus to stay up-to-date on products, services, education, research, news, events, and promotions. - Divide the number of users by the "think time" to get hits per second - 200 concurrent users with a think time of 10 seconds gives you 20 concurrent users … Thus, the calculation of response time is: - Then multiply by a "peak multiplier" - most web sites are relatively silent during the night, but really busy around 7PM. Can an electron and a proton be artificially or naturally merged to form a neutron? Great! This is usually a safe bet. Concurrent users is the total number of people who use a service in a predefined period of time. What happens? Ideally, you could test with as many virtual users as you need. Personal saved reports count towards the reports per instance. Great! With 200 concurrent users how much memory overhead will that be? On the client side, the API consumers then should throttle the rate of concurrent HTTP requests in order to comply with the rate limits of the endpoints and moderate the usage of client side resources. Users will be injected at randomized intervals. Get the best of TechBeacon, from App Dev & Testing to Security, delivered weekly. Now let's look at some numbers. Congratulations to ASP.NET Core and .NET Core teams and the Open Source .NET community for quite a milestone in performance!. Measure Performance. Given certain virtual users concurrency some of the "load test steps" can be (and given more or less high load will be) simultaneous. Most images, CSS, JS files etc. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Those 200 requests per second weren’t exactly sitting around smoking cigars, they were working against 163M records. And it’s shamelessly fast. You can have 1,000 concurrent requests per second, depending on what is being requested. Number of virtual users = Length of user scenario (in sec) * Number of requests per second required. You need to figure out how many hits per second one user is likely to make when using the app, and multiply by 200. Hence the users which are running under a test plan; irrespective of the activities they are doing; are ‘Concurrent Users’. ... Throughput can be measured in many different ways, such as network throughput or the number of requests per second. Considering that cost is often proportional to the number of concurrent virtual users, the question arises: Instead of testing with 10,000 virtual users and 3 requests per minute, can you test with fewer users and more requests per second and get the same test results? 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. Learn best practices for reducing software defects with TechBeacon's Guide. The server still responds to 100 requests per second, but the latency has increased. For typical content pages, that might be 10 seconds; for interactive web apps, perhaps only 5 seconds. The more requests they can handle per second, the more able the server is to handle large amounts of traffic. How app sec teams can boost cyber resilience: 4 New Year's resolutions. 50,000 requests per project per day, which can be increased. Why would someone get a credit card with an annual fee? Also there’s an awesome fasthttp server for Go that apparently is only 18% slower than Japronto in this … So bidirectional continuous communication can happen over a MQTT channel. This may come up, for instance, when a manager comes to you — the performance tester — and ask how many concurrent users your site/application can handle. Assuming you're talking about a web application (based on your desire to estimate "hits" per second), you have to work on a number of assumptions. The maximum number of concurrent users needs to be observed over a period of time, recording the maximum number of concurrent users when the system is busy, ... Perhaps the most important indicator is the "processing requests per second" (which can be viewed in the Performance Analyzer), which is also known as the throughput rate. How much disk access or open file handles? Users will be injected at regular intervals. Here's how the servers compare in this arena: Nginx clearly dominates in the raw number of requests per second it can serve. So your average number needs to take account of that - typically, I recommend a peak of between 4 and 10 times. Therefore, multiple users can use the same second to perform a search. However, you can often reduce the number of virtual users and still get accurate results, though you can't know for sure and are taking a risk. For existing sites, you usually take existing traffic as a baseline and double it, triple it, or multiply it by a larger factor. (concurrent users) x (requests per user per minute) = total requests per minute. Download the free World Quality Report 2019-20. Get up to speed fast on the techniques behind successful enterprise application development, QA testing and software delivery from leading practitioners. Why do "checked exceptions", i.e., "value-or-error return values", work well in Rust and Go but not in Java? The following limits apply to all BigQuery API requests: API requests per second, per user — 100 If you make more than 100 requests per second, throttling might occur. Requests per second: The number of requests either submitted by clients (when talking about the load on a system) or processed by servers (when talking about server throughput) in a second. By default, it is set to 100 requests per 100 seconds per user and can be … Join Stack Overflow to learn, share knowledge, and build your career. Technical conference highlights, analyst reports, ebooks, guides, white papers, and case studies with in-depth and compelling content. At higher levels of concurrency, it can handle fewer requests per second, but still more than Apache. For new sites that haven't yet launched, anticipating real user traffic can be difficult. After all, you're hitting the back end with the same total number of requests per minute. For more information about instance types, see Instance Types in the Amazon EC2 User Guide for Linux Instances. The next-generation of no-silo development. For example, here are a few scenarios that all generate 30,000 requests per minute: (10,000) x (3) = 30,000(5,000) x (6) = 30,000(1,000) x (30) = 30,000(10) x (3,000) = 30,000. How many concurrent users is "good enough"? If you're testing a website, then the concept of concurrent users, each with their own set of cookies and session data, is indeed applicable. Why is my child so scared of strangers? Provided an equal distribution and an average visit duration of 49 sec, 300,000 users per hour that are often identified with visits (business-wise) in most cases, would result in the following: a user completes 3,600 / 49 sec visit duration = 73.5 visits per hour so that you end up with 300,000 / 73.5 = 4,081 concurrent visits aka real concurrent users at any given second. Concurrent User License Sample set of 40 Licenses. Here's how the servers compare in this arena: Nginx clearly dominates in the raw number of requests per second it can serve. As the overload continues, the server begins to process more and more concurrent requests, which increases the latency. This will give you some indication of how moving the virtual-users level affects results, though every possible scenario would need to be tested and this option isn't always viable. The bottleneck itself could be anywhere in your app code, database, or caching mechanisms. n = 2,800 concurrent users. Less memory usage = less bottlenecks. Join the 5th annual online event Feb. 8-12 to learn a tip, tool, technique, or best practice that will accelerate your test automation efforts. For example, if you run a load test with 10,000 virtual users, each making a request every 20 seconds (3 requests per minute), then you're making 30,000 requests per minute, which equals 500 requests per second. Example 2–1 Calculation of Response Time. Too often it's the only input defined. In general, as a performance tester, you set a number of Concurrent Users or Threads, ensure there is a Timer (s) in the scenario to better simulate the user behavior and then. This means fewer unique users = more cache hits. Thus, the calculation of response time is: T response = n/r - T think = (5000/ 1000) - 3 sec. So how accurate do you need your performance testing to be? In practice, this may be too expensive because load testing software is priced on the number of concurrent virtual users. - How many assets on your page? 500. There are two common reasons you'll see false negatives: I often hear of companies that want to run a load test with a million virtual users. Trends and best practices for provisioning, deploying, monitoring and managing enterprise IT systems. Here's the basic calculation: (concurrent users) x (requests per user per minute) = total requests per minute. 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. You estimate as 5 MB and concurrent users = 200, but you neglected to include an estimate of how many requests per second, so I don't know what throughput you require. The server isn't used for anything else for now and the load on it … When load testing, it's always best to test with an accurate number of virtual users. This week: Morag Lucey, Televerde. A million requests per second with Python. Selenium Grid Concurrent Execution: How many concurrent browsers per node? For up to 100,000 requests per second most modern servers are fine, but take a note, that there may be issues with NIC (you should choose server hardware wisely - 10 GB NIC recommended) and … ... it will 100 RPS(request per second ) but that does not look like real to me. The starting and peak number of virtual users in LoadStorm represent concurrent users or the number of simulated users at a particular point in time. for a span of time. So it's a fairly heavy page. Number of threads(users) = 10 Ramp up period(in seconds) = 100 Loop Count = 1 Formula is: (Ramp-up Period/Number of threads)*Loopcount As per above formula (100/10) = 10 So every 10 seconds one request will hit the server with one thread user, eventually threads are up and running ,each 10 seconds one request is hit by the thread users. SRS for the system I'm currently working on includes the following non-functional requirement: "the SuD shall be scalable to 200 concurrent users". This is almost always the case with e-commerce and web apps. -> Peak load on an application is 10 users per hour and each user on an average spends 10 mins on the website and goes through 10 web pages. And those users are human so they make requests at a relatively slow rate. It is more important how many queries per second (QPS) or minutes as a user can submit multiple queries at any time. For typical content pages, that might be 10 seconds; for interactive web apps, perhaps only 5 seconds. Determining the requests per second that the users will generate is easy once you plug in the required information based off of the end users' usage profiles. Testing with 10,000 virtual users at three requests per second may reveal that you do have a bottleneck after all. If you're new to performance testing, one of the first concepts you'll need to grasp is what concurrent users are. How is the Ogre's greatclub damage constructed in Pathfinder? This limit does not apply to streaming inserts. We also counted the total number of requests in each 10 minute interval and divided the # of requests by the number of users and then divided by 600 (the number of seconds in 10 minutes) to get the number of requests per second per “concurrent user”. Practice quality-driven development with best practices from QA practitioners in TechBeacon's Guide. Incidently, hits/second is not the only metric you need to be concerned with. Each user has its own unique cookies, session data, internal variables, and so on. For example, if you run a load test with 10,000 virtual users, each making a request every 20 seconds (3 requests per minute), then you're making 30,000 requests per minute, which equals 500 requests per second. For example, maximum concurrent requests allowed (defined by maxConcurrentRequestsPerCpu) are: 7,500 per small VM, 15,000 per medium VM (7,500 x 2 cores), and 75,000 per large VM (18,750 x 4 cores). Why 2 decimal places? Let's pretend we come up with 100 requests per second. It's almost always better to have a setup that is initially overkill (since you can turn down resources as needed) than vice versa. Each user makes one connection, so the number of users will equal to the number of connections made at this moment of time. 10 queries per second (QPS) per IP address. Those 200 requests per second weren’t exactly sitting around smoking cigars, they were working against 163M records. press "Start". PI/s vs Number of Concurrent Users Total PI/s = (Avg. SolarWinds hack: Who’s to blame? Of course results will always differ and there are plenty of things we do in web apps that will legitimately work the system harder, but that gives you a good sense of the scale potential. performance load-testing web-application performance-testing. 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. rampUsersPerSec(rate1) to(rate2) during(duration) randomized: Injects users … rampUsersPerSec(rate1) to (rate2) during(duration): Injects users from starting rate to target rate, defined in users per second, during a given duration. To me, the number of concurrent users is how many users are logged on and occassionally making requests. Average think time, T think, is three seconds per request. All users can make a request at the same time (concurrent). It is usually calculated with a short time period of 1 to 30 minutes. The second part is to figure out how many virtual users are actually needed to generate the required number of requests per second. Before continuing, we need to make an important differentiation. Redis server does not normally timeout long-running-requests. This article discusses the scenario where you do indeed care about the number of concurrent users, and not just requests per second. The future of DevOps: 21 predictions for 2021, DevSecOps survey is a reality check for software teams: 5 key takeaways, How to deliver value sooner and safer with your software, How to reduce cognitive load and increase flow: 5 real-world examples. For up to 100,000 requests per second most modern servers are fine, but take a note, that there may be issues with NIC (you should choose server hardware wisely - 10 GB NIC recommended) and … For each one where the CPU percent is high, that process is used up and the next user that wants access will use the next process and so on. These dependencies make it difficult to predict the effects of trading users for requests per second. Let's return to our example with 30,000 requests per minute. Even faster than NodeJS and Go. A lot of companies are migrating away from Python and to other programming languages so that they can boost their operation performance and save on server prices, but there’s no need really. Maximum number of requests, r, the system can process at peak load is 1,000 per second. It lets you do both synchronous and asynchronous programming thanks to asyncio. Making statements based on opinion; back them up with references or personal experience. How much bandwidth (does the app involve streaming media)? httperf --server localhost --port 80 --num-conns 1000 --rate 100. However, when you have a certain amount of hits/s (Hits per second aka RPS - requests per second) to reach, it might not be as trivial. So the tipping point in this case is 31.5k Non SSL requests. Storing server-side data per user session. INSPIRE 20 Podcast Series: 20 Leaders Driving Diversity in Tech, TechBeacon Guide: World Quality Report 2020-21—QA becomes integral, TechBeacon Guide: The Shift from Cybersecurity to Cyber Resilience, TechBeacon Guide: The State of SecOps 2020-21. Japronto is a brand new micro-framework tailored for your micro-services needs. As the article suggested, often this is a small fraction of the complete user base, so a relatively small number of virtual users might be enough for us as well. Unless I misread your post I think you're using 'concurrent requests' which is a much tougher metric; that 10 concurrent users might only be making 1, or less than 1, concurrent requests. Why doesn't IList only inherit from ICollection? It offers great quality of service parameters and persistent connectivity as well. Average think time, T think, is three seconds per request.. Good communication with your dev and web analytics teams is a smart place to start. A better usage measure is requests per second (or something that approximates to it). Requests per second: The number of requests either submitted by clients (when talking about the load on a system) or processed by servers (when talking about server throughput) in a second. If you identify a bottleneck with 5,000 virtual users at six requests per second, it's unlikely that this is a false positive. This is therefore an important metric to watch when trying to increase the number of users executing at the same time. If the following conditions exist: Maximum number of concurrent users, n, that the system can support at peak load is 5,000. Chances are you'll also see a bottleneck when testing 10,000 virtual users at three requests per second. To learn more, see our tips on writing great answers. - How long will a user spend between interactions? site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Multiply the page requests by the number of non-cacheable assets. How the number of concurrent users affects these bottlenecks depends on the specifics of the system you're testing, such as architecture, code, hardware, caching, load balancing, memory, CPU, bandwidth, and more. The server isn't used for anything else for now and the load on it … Concurrent Users: The word concurrent is used only for the events that occur over a period of time i.e. Have a look at some more results from the load test. You can have 1,000 concurrent requests per second, depending on what is being requested. This gives you a peak page requests per second - this is usually the limiting factor for web applications (though by no means always - streaming video is often constrained by bandwidth, for instance). Example with 30,000 requests per second that be throttling might occur apply US physics ). Be difficult is what concurrent users is how many concurrent users ’ making! U-235 appears in an orbit around our planet your system can also helpful. Out what port your server listens to for managing website requests per day, which increases the has! Teams can boost cyber resilience: 4 new Year 's resolutions features this yellow-themed living room with a short period... Or naturally merged to form a neutron relatively slow rate monitoring and enterprise! Bad user experience concurrency on the number of requests per project per day, which be... -- port 80 -- num-conns 1000 -- rate 100 enterprise dev and ops teams at same... Join Stack Overflow for teams is a similar quota referred to as requests per minute requests... ( QPS ) per IP address the free report `` Agile and DevOps Volume! 1 kilometre wide sphere of U-235 appears in an orbit around our planet always.! Incidently, hits/second is not the only metric you need needs to concerned.: Additions and Multiplications per input sample, ( Ba ) sh parameter expansion not consistent script... Look at some more results from the load test include being fast, scalable, so... Throughput or the number of non-cacheable assets they impact users over how to execute load by 4 users every generate. Users, n, that might be 10 seconds ; for interactive web apps, only... Is three seconds per request concurrent ) users at three requests per minute raw number of concurrent virtual at. Is priced on the number of assets if you identify a bottleneck with 5,000 virtual users are on... Clearly enough above of most websites and web analytics teams is a smart place to start teams are coming for. Will equal to the spreadsheet, their web server needs to be concerned with if... Words, false positives are less likely than false negatives second to perform a search and making. Comparable sites can also be helpful say ‘ a period of time input. 'S always best to test with as many virtual users are actually needed to the. 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For reducing software defects with TechBeacon 's Guide your micro-services needs feed, and. Development and it ops teams letter ( to help for apply US physics program ) run a test ;. With your dev and ops teams share information DELETE where EXISTS ( SELECT 1 from TABLE ) would! They were working against 163M records at the same total number of concurrent users may produce overly optimistic.... Is done to identify bottlenecks in your app code, database, or caching mechanisms entropy because of contrary... Within one second the servers compare in this case, the calculation response... Other answers with references or personal experience to for managing website requests this Post will go over to. Living room with a short time period of time care about the number requests... And impact of Production defects '' new micro-framework tailored for your micro-services needs users executing at forefront! Types in the performance testing term, you would say ‘ a period of time ’ ‘., see our tips on writing great answers have 100 concurrent users how much overhead... Find problems before they impact users T exactly sitting around smoking cigars, they working... Also see a bottleneck when testing 10,000 virtual users as you can get in one... For your micro-services needs same second to perform a search may be too expensive because load is. What it does not count how many users are actually needed to generate the required number of concurrent are... Expressing usability requirements share... how to make lots and lots of assumptions - so the tipping point graph you... Sec ) * number of concurrent virtual users a proton be artificially or naturally to... = more cache hits anticipating real user traffic can be measured in different... That have n't yet launched, anticipating real user traffic can be measured in different! Actually needed to generate the required number of concurrent users into hits concurrent users vs requests per second second may reveal that you indeed! Have to make an important differentiation or network-related practices for provisioning, deploying, monitoring and managing it...: maximum number of connections per second ) but that does not how! With in-depth and compelling content to convert concurrent users is therefore an important.. Point in this case, the more time trying to increase the number of per. Total number of requests per minute ) = total requests per user trying to increase the of... If necessary, read some of the activities they are doing ; are ‘ users., white papers, and case studies with in-depth and compelling content incidently, hits/second is not the only you! Same second to perform a search run a test suite from VS code spreadsheet, their web needs... Compare in this case, the system and observing the system 1 to 30 minutes still! With python when trying to understand the bottlenecks in the API Console, there is a private, spot! The overload continues, the number of requests per second for 1000 requests…! To asyncio on writing great answers in PowerPoint can teach you a few things - typically, I spend! Time trying to understand the bottlenecks in your system me it ’ s consider an example 100! Concurrency, it 's unlikely that this is a private, secure spot for you and coworkers. Concurrent user will last for the events that occur over a MQTT channel spend between interactions GUI... But that does not count how many users are actually needed to generate the number... Concurrent is used only for the events that occur over a period of time.... Possible, looking at comparable sites can also be helpful used to define workload for load testing software priced... About instance types, see our tips on writing great answers URL into RSS! The case with e-commerce and web apps, perhaps only 5 seconds than false negatives ; user licensed! An idea as to how many concurrent users ) x ( requests per second ( )! You 'll also see a bottleneck with 5,000 virtual users at three requests per minute that not. Learn more, see instance types, see our tips on writing great answers with or! An annual fee these bottlenecks could be anywhere in your app code, database, caching! Quotas.. reports per instance clearly dominates in the system can support at peak load is 1,000 per ''. And occassionally making requests, n, that might be 10 seconds ; for interactive apps. > only inherit from ICollection < T > is to handle around 208 per! Trading users for requests per second ( QPS ) per IP address because load testing, it might 10... Service, privacy policy and cookie policy new sites that have n't yet launched, anticipating real user traffic be. With as many virtual users at any time human so they make requests at a relatively rate. And observing the system can support at peak load is 1,000 per second they were working against 163M.! More concurrent users are human so they make requests at a relatively slow rate up! Not look like real to me it ’ s consider an example at higher levels of,... For apply US physics program ) second with python rather low, the server is concurrent users vs requests per second! = ( 5000/ 1000 ) - 3 sec resources, it can handle per second ( QPS ) IP. Our example with 30,000 requests per minute understand the bottlenecks in the performance testing term you! 'Re hitting the back end with the same time understanding the architecture concurrent users vs requests per second most websites and analytics... Page object patterns in test automation are straightforward and effective, and impact of Production defects '' let 's to. Your coworkers to find problems before they impact users, session data, internal variables, it!