How to adjust JMeter repeat requests? - jmeter

I'm testing the performance of my website using JMeter.
1000 users were forced to log in sequentially and call the sub-page periodically (using Loop Controller).
The interval for sub-page calls was made to be called every 10 seconds using the Constant Timer.
As 1000 users accessed DB data at the same time every cycle, the CPU load of DB increased by 100%.
Can only 50 out of 1000 logged-in users access the sub-page every second?

You can put the "sub-page" request under a Throughput Controller and specify the desired frequency of the requests execution there:
More information: Running JMeter Samplers with Defined Percentage Probability
However you should realize that artificially limiting the load will lead to false positive results so you might want to perform the query optimization or increase the DB server resources instead

Related

JMeter How to prevent concurrent calls when running stepping thread group

Ok so I am experiencing an issue where I am supposed to ramp up 10 vusers in 1 minute till it reaches 200 Vusers and hold the load for 60 minutes. However, as it calls 200, it is calling all of them concurrently which is affecting the performance of my test. Right now, I want to call the 200 vusers which each users being called with an interval timing in between instead of one shot concurrent call.
The real users don't hammer the system under test non-stop, they need some time to "think" between operations.
Well-behaved JMeter test must mimic real user using a real browser with 100% accuracy including cookies, headers, cache, etc.
This "think time" is also uber-important, real users need to read the content of the page before navigating to the next one. If they're supposed to type/write/upload something - they will need even more time.
So in order to accurately simulate this "think time" you need to add a suitable Timer(s) and configure them properly in order to introduce reasonable delays between requests.

Validate newly created server support the same load

We are creating a new hosted server for one of our APIs on managed containers (Kubernetes) and we're trying to validate that it can handle at least the same amount of traffic load requests.
We've started with one of the APIs, where we would need to handle at least 140k requests per minute, all endpoints combined.
To verify this, I created a simple JMeter test as follows:
-Test Plan
---Thread Group Endpoint1
-----HTTP Request -> a GET request with query params for /path1
---Thread Group Endpoint2
-----HTTP Request -> a GET request with query params for /path2
For a local test, I used the following setup:
Thread Groups Endpoint1 and Endpoint2 are set to 200 threads (users), ramp-up period of 1s, loop count = forever and duration 60s.
Using a Summary Report listener when running the test gets me a total of ~9300 # Samples.
Using this approach, is it safe to just increase the number of threads (users) for the Thread Groups until I reach the desired 140k requests per minute?
Note: I only used JMeter a little before, so I'm aware that the entire approach may be wrong, therefore any suggestions and steering to the right path are more than welcomed.
Your approach is viable as long as it represents real-life application usage. If it has 2 endpoints with equally/evenly distributed load - your setup is just fine. If there are more endpoints and some of them are used more than the others - consider defining the workload correspondingly either using different Thread Groups or other distribution mechanism such as Throughput Controller
Increasing the number of threads is also fine, however consider increasing the load gradually, to wit increase ramp-up time so your test could have:
Arrivals phase
Time to hold the load
Ramp-down phase
This way you will be able to correlate various metrics like increasing response time, throughput, number of errors, etc. with the increasing load. Also you will be able to state what was the number of threads/requests per second when the system reached saturation point/breaking point and does it recover when the load gets back.
Also make sure you're following JMeter Best Practices as 2300/2500 requests per second is not something JMeter can support out of the box and you will need to do some tuning, at least increase JVM Heap size allocated to JMeter.
You may not be able to achieve the desired 140k requests per minute using a single Jmeter Machine, in that case you'll need Distributed Load Testing approach here.
refer: http://jmeter.apache.org/usermanual/jmeter_distributed_testing_step_by_step.html
Also keeping the ramp-up period of 1 second will lead to spike and unrealistic load in the system which will not give proper result unless you've pre-warmed your server, you should gradually increase the load as per real/estimated traffic pattern.

How do I load test sequential APIs one by one using Jmeter

I'm using Jmeter to load test an application.
No: of threads is 100.
First HTTP request is the home page.
Second HTTP request is login page where the actual login is made
.
.
n APIs are there.
and what I want to achieve is:
First 100 threads hit the home page concurrently.
Then 100 threads hit the login page concurrently.
.
.
Then 100 threads hit the nth API concurrently.
Add Synchronizing Timer as a child of each request which you need to execute "concurrently"
Set Number of Simultaneous Users to Group by to be equal to the number of concurrent users, in your case 100
Reference: Using the JMeter Synchronizing Timer
Although above approach answers your question better scenario would be starting with 1 virtual user and gradually increase the load, in this case you will be able to correlate increasing load with performance metrics like Response Time, Transactions Per Second, resources consumption of the application under test, etc. as the situation when 100 users open login page and then hit "Login" button at exactly the same moment is highly unlikely to happen and well-behaved load test needs to represent real usage of the application by real users as close as possible.
Threads number 100 ,You need to put each request with synchronizing timer under 3 controllers, See tutorial

jmeter calculate page load time, the which type of thread to be used to observe the maximum load in which server is stable

I am new to jmeter and scripted for login authentication. Project requirement is to see the load for 10K concurrent users.
Script is working fine but to enhance I need suggestions on how to do the following thigs:
How can I see that how much time/average time the server takes to load a page.
which thread grp (studied Ultimate thread group but it is not very clear to me), should be used to see the maximum load the server can sustain in a particular time, for that rampup time need to be adjusted (correct me if I am wrong).
Please tell how to adjust the rampup time with respect to users/waiting time etc., in short how to do incremental/proportional observation to see the server performance(there is no Gateway error etc)
If you're looking for your server capacity boundaries I would rather stick to "requests per second" rather than to "concurrent users" as users may work with different applications in a different way.
For instance, if it is image gallery - the majority of users will be browsing images and do this rather frequently, for instance request next image i.e. each 2 seconds. Given image load time 1 second it will be an image per 3 seconds - 20 images per minute. In this case 10000 users will create the load of 3333 requests per second.
If your site is articles collection, users will need some more time to read an article, i.e. 2 minutes. In that case 10000 users will create 83 requests per second load.
JMeter provides Constant Throughput Timer out of the box, you can set desired target throughput in requests per minute using it. And once you're already aware of JMeter Plugins project, it offers Throughput Shaping Timer - more advanced test element with extended functionality.
If you go "throughput" way, no matter which Thread Group you choose as the load will be orchestrated by aforementioned timers.
See What is the Relationship Between Users and Hits Per Second? article for more detailed explanation.
Once you design your test scenario run it in non-GUI mode (as JMeter's GUI is very resource intensive) as:
jmeter -n -t /path/to/your/testplan.jmx -l /path/to/resultsfile.jtl.
When the test finishes, open JMeter GUI, add Aggregate Report listener and inspect min/max/average response times per requests.

Something like thread.join in JMeter?

I have a jmeter test with about 50 users. the beginning of the test performs a login and some set up stuff. I don't want this all to happen at the same time as there would be way too much contention for a part of the test I am not interested in. So I have a ramp up period of 10 seconds. There is then one specific HTTP request where I want the 50 users sending over 1 second interval i.e. a HTTP request every 20 ms. This is to ensure the 50 users are excuting this part concurrently. Ideally, something like a thread.join() after the login / ramp up would help out here, followed by another guassian timer.
Is there something similar to thread.join() in jmeter?
To mimic thread.join you can use a Synchronising Timer, this will block n threads until they reach a point and then execute them all at the same time.
If you want this request load of 1 every 20ms to continue (rather than a single burst) then you can use a Constant Throughput Controller to define the actual rate of requests you want JMeter to run. You can configure each thread to run at a rate of 60 requests per minute and this will give you one hit every 20ms (based on 50 threads with response times always less than 1 second). You can also tell JMeter to just make sure your load is 1/20ms no matter how many threads you use and it will dynamically adjust. This option is perhaps more useful in the context of load testing.
Note. When using a CTT controller, you would probably want to put the login request either in a Once Only COntroller or in a setup thread group.

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