Is it even possible to fake the traffic, considering your network connection will have a bandwidth limit? If I create a test for 1000 users, visiting 3 pages a second, will the results really represent this scenario if done in real life (not simulation)?
Should I create an executable to perform the load test, and run it from separate network connections?
It looks like you have a concern that the network bandwidth limit of the test machine will invalidate the accuracy of the test. To determine if your concern is legit, perform the following rough assessment. Let say your three pages have sizes 20k, 40k and 60k respectively. To load test them you would need to generate the following maximum bandwidth:
1000x (20k+40k+60k)= 120Mbps
Make an adjustment for compression if you use it. Factor in the requests sizes if they are significant. If you test with browser caching emulation enabled, increase the size of the first requests by the size of static resources. Then compare the maximum bandwidth with your network adapter bandwidth. If it is 100 Mbps, then the network adapter will be a bottleneck. If it is 1 Gps or more, then the network adapter will not be a bottleneck.
Alternatively, skip calculations and just run the test. On the bandwidth graph in VSTS find the max value. If it is by far smaller than your network adapter limit, then you can run this test from one machine.
Keep in mind that requesting 1000 x 3 pages per second does not guarantee that you will receive responses from 1000 X 3 pages per second due to the server speed limit.
Related
I need to load test my website with 10k req/sec for 1 hour using JMeter. I am confused with the values of loop count, number of thread, ramp-up period and duration.
Also will my laptop (i5 8GB) be able to do that? If not what is the alternative.
PS: I checked every question/answer on stackoverflow for this but I couldn't find any help. Please dont mark it repeated question.
You can use "Constant Throughput Timer" and define target throughput and select throughput based on "all active threads".
Define maximum number of users count in your script so that it will be enough for 10K req/sec.
Also if you are using windows machine then I think you will face this issue "https://www.baselogic.com/2011/11/23/solved-java-net-bindexception-address-use-connect-issue-windows/"
I will recommend to use distributed testing or use more than 1 machine.
The easiest way of configuring JMeter to send X requests per second is using either Precise Troughput Timer or Throughput Shaping Timer in combination with the Concurrency Thread Group. The number of threads needs to be sufficient, the exact number mainly depends on your application response time, if response time is 1 second - you will need 10k threads, if it's 500ms - you will need 5k threads, if it is 2 seconds - you will need 20k threads, etc.
Only you can answer whether your laptop can kick off the required number of virtual users as there are too many factors to consider: nature of the test, the size of the requests/responses, number of pre/post processors and assertions, etc. Make sure to follow JMeter Best Practices and monitor CPU, RAM, Network, etc. usage using i.e. JMeter PerfMon Plugin as if your laptop will be overloaded - JMeter won't be able to send requests fast enough and you will not be able to conduct 10k requests per second even if the server supports it. If your laptop hardware specifications are too low for the test scenario - you will have to go for Distributed Testing
You have a number of issues in play
test design. Use more than one load generator. In fact, use no fewer than three, evenly matched in hardware. Take one and load only one user of each type. This is your control set. If this set degrades at the same rate as your other load generators then you have a common issue, likely the site. If the control set does not degrade, but the other load generators do, then you likely have an overloaded generator. On the commercial test tool side of the fence, generating all load from one host have never been considered a good practice in performance testing.
10K requests per second. This is substantial. I have worked on some top 20 eCommerce sites and I can tell you that even they do not receive this type of traffic to the origin servers. Why? Cache! Either this his a Content Delivery Network where the load is spread across the county, OR there is a cache node directly in front of the load balancer(S) for the site (thing varnishcache of equivalent), OR both for a multi-staged cache. You might want to look for an objective reference in production to pin this to as a validation poinnt, if and only if (IFF) your goal is to represent end user behavior. Running a count of requests grouped by second from the HTTP access logs should be able to validate this number. Also, check the cache plan for fixed assets - it could be poorly managed and load would drop significantly just by better managing the sites cache settings to the client. If your goal is simply to saturate a SOAP/REST interface to the point of destruction then you might have a better path.
If you are looking to take a particular SOAP or REST set of remote procedure calls to the point of destruction, consider a classical stress test. Start your test at zero load, increase with the smallest step interval possible over the longest possible period of time. The physical analogy to this would be the classical hospital style stress test where a nurse comes around every minute and increases the speed OR the incline on the treadmill OR both until some end of test condition is achieved. For a hospital style test that is moving into Oxygen debt, an inability to keep pace, etc... For your application/interface it could be the doubling of response times from what is acceptable, a saturation of resources in the finite resource pool (CPU, DISK, MEMORY, NETWORK) on the back end hosts, etc...
Is that possible to execute 10000 concurrent user in jmeter?
If so how?
What should be the ram-up time for this scenario??
JMeter's limit of virtual users per Thread Group is very high, to be precise it's 2,147,483,647
The question is: do you have good enough hardware to simulate 10 000 users from a single machine. The process of checking it looks as follows:
Make sure to follow JMeter Best Practices
Set up monitoring of the CPU, RAM, Network, Swap, Disk usage on JMeter side, it can be done using JMeter PerfMon Plugin
Start with 1 virtual user and gradually increase the load at the same time looking into CPU, RAM, etc. usage. Here there could be 2 options:
you will be able to reach 10 000 users without issues, if this is the case you should be good to go
you will run out of resources earlier, in this case look into i.e. Active Threads Over Time listener to see how many users you were able to simulate from this machine and extrapolate the value to determine how many load generators you will need for 10 000 users using Distributed Testing approach
There is no golden rule for ramp-up time calculation, the good practice is to onboard the users gradually, this way you will be able to correlate increasing load with increasing response time, increasing number of errors, etc. Adding 3 users each second so in 1 hour you will have 10 000 seems a valid starting point to me.
I have a scenario with 5K HTTP requests. When I start JMeter with it, JMeter simply hangs after about 170 users. I followed all the guidelines for successful stress testing (no listeners, headless, increased heap space).
I must say that some of those requests are a little big, the overall file is ~115M.
When I only take a subset of the requests (~100), the simulation works better (faster initialization of users, holds more than 170 users, etc).
My question is, first, as I understand JMeter loads the scenario tree and every threads plays it, there should not be any duplication, so what exactly causes this extensive load? and second, what can I do about it?
PS: when I view the system bottlenecks I notice both CPU and memory are at very high values on the long file, both of the metrics have low values on the shorter version. Anyone can explain?
PS2: the requests have about 7 seconds of delay between them
First I need to let you know that if you are using a single system to do the load testing, the maximum your hardware or the port can handle at a time is 1 Gig of data. and your firewall(if any) would again receive/pass not more than I Gig of data. Try doing the same load test with Distributed System of load testing in Jmeter(Master-Slave-Distributed System). Even then, I don't think it would run for 4k requests(if these requests are heavy).
Best possible solution:
Try Distributed system as I mentioned above.
Try running the load test in Non GUI Mode- CLI
Increase the ramp up time as needed.
Increase the Ram of your system and allocate maximum available heap space to jmeter.
Drastic change- Use 1. Blazemeter cloud or 2. Move the complete setup of your load testing to Amazon Server which is more reliable and scalable.
Hellow
Which is the maximun number of virtual users that can be testet at a Jmeter distributed test? Is it possible to reach one million of virtual users?
Thak you.
It depends on may factors, technically the limit on JMeter end is very high (I think it should be 231 − 1 or 2 147 483 647 virtual users)
Nature of your application: use cases, is it more about consuming ore creating content, average request and response size, response time, etc.
Nature of your test: again, request and response size, need to use pre/post processors and assertions
Hardware specifications of your load generators
Number of load generators
So I would recommend the following approach:
Start with a single JMeter instance
Make sure you have optimal JMeter configuration and amended your test according to JMeter best practices
Make sure you have monitoring of baseline OS health metrics on that machine
Start with 1 virtual users and gradually increase the number of running users until you start running out of hardware resources (CPU or RAM or Network or Disk IO will be close to maximum)
Mind the number of active users at this stage (you can use i.e. Active Threads Over Time listener) - this is how many users you can simulate for particularly that test scenario. Note, the number might be different for other application or other test scenario.
Multiply the number you get by the number of the load generators you have - if there is > 1M - you are good to go.
If you won't be able to simulate that many users there is a workaround, but personally I don't really like it. The idea is that real users don't hammer application non-stop, they need some time to "think" between actions. Normally you should be simulating these "think times"using JMeter Timers. But if you lack load generators you can consider the following:
Given 1 virtual user needs 15 seconds to think between operations and response time of your application is 5 seconds, it means that each user will be able to execute only 3 requests per minute. So 1M of users will execute 3M requests per minute which gives us 50 000 requests per second which is also high, but more likely to be achievable.
We have a simple Java web application and we are performance testing it with a test case, where we upload a 1 MB file to the application under test. We have several locations around the world where we can test it. From some far locations the transaction response time seems to grow very fast under load, but from most places it stays steady. The used load is not high and network shouldn't be a limiting factor. What else could it be?
Your remote network saturation is the limiting factor.
If it was inbound then all locations using the same inbound interface would be subject to the delay. As you indicate that only some of the locations are impacted we can use the non impacted as control elements of the test to determine that it is not the common inbound interface.