Which tools can be used to measure performance of a webserver?
To test a webserver, you can use Apache Jmeter.
To see where is the bottleneck you have to flood your server application.
ApacheBench (ab) can do this. Here is a tool to get the server HTTP response code (ab) just says there is an HTTP error, and to automate test runs:
dsec.com/source/ab.c.txt
This program also gives useful tips about how to configure Linux and Windows (TCP/IP system options) to get the best possible performances.
It always depends on the setup.
Depending on the application there can be different bottlenecks.
Sometimes its the CPU, sometimtes the database connections, sometimes the sockets, sometimes the hard disc etc...
Most common practice is to use siege (simple command line tool) and increase the concurrent connections and see how many transactions per second go through.
It will increase per connection until an optimum is reached, then it will slowly decrase.
You can produce a set of urls that are randomly accessed, maby biased and/or send random data, request random ids etc to simulate more "real" clients.
Completely depends on your application whether this is relevant.
Related
I conducted performance testing on e-commerce website and I have the test results with some matrices. I already found some problems on some component for example on checkout or post login with high response time and error. But I also would like to find issues that are limiting the application to scale. I only did the testing on the application server. And I observed that CPU , I/O rate are very stable as well. But still the application gives high response time. Is there any other way I can determine from the test result why it is not scaling well? Thank!
From JMeter test result only - unlikely, JMeter just sends requests, waits for the responses and measures the time in-between plus collects some extra metrics like connect time and latency, see the JMeter Glossary for full list with explanations
The integrated system acts at the speed of its slowest component, possible reasons could be in:
Network issues (i.e. lack of bandwidth, faulty router, long DNS resolution time, etc.)
Your application is not properly configured for high loads. Inspect the current setup of the application in terms of thread pools, maximum number of open connections, any limitations on resource usage, etc. Look for documentation on performance tuning of individual middleware compoments as well.
Repeat your test run with a profiler tool telemetry enabled or look at the APM tool output for the test time frame if the tool is in place, it will allow you do perform a deep dive into what's going on under the hood of this or that function call as it might be inefficient algorithm or a slow database query
I need to test 200.000 VU hitting an app in 10 seconds, so I started to make a test of 10.000 VU, running Jmeter in Non-GUI mode, to see the response of my computer, my internet connection and the site response, but I got 83.50% of Errors.
95% of the errors were these:
Non HTTP response code: java.net.ConnectException/Non HTTP response message: Connection timed out: connect
This means that the internet connection was not enough for the short time of the test?
Thanks.
Running 200K users
Generally speaking in traditional HTTP running 200.000 users from one machine is impossible: there isn't that many ports. I.e. if you maximize your port usage (and it's likely you need to change OS settings to do that, since usually OS will limit number of open ports to somehwere between 1000 and 10000), JMeter will have about 64500 ports to run requests on. Each JMeter HTTP sampler needs a separate port, so you need 200K ports. Thus you need to have at least 4 machines to run 200K requests concurrently.
But that may not be enough: if you have more than one request sequentially (like most performance tests do), you will be able to run even less concurrent requests, since ports are usually not closed right away after request is done, so next request has to use a different port.
Don't forget that server also must be able to receive similar load.
But even that may not be enough: JMeter needs to have enough memory to accommodate 10-30K threads. Size of thread in memory will depend on a few things, and how your script is designed among them.
Bottom line: with all the tweaking, realistically, port availability limits number of concurrent requests JMeter can run from one machine to 10-30K concurrent users. Thus to test 200K users, you need about 7-20 JMeter machines.
Running 10K users
If you were testing in a designated environment (where clients and servers are next to each other with optimized network between them), you should be able to run 10K users from one machine, if other limits, e.g. memory and max ports were properly tweaked. But sounds like you are trying to test them over the internet connection?
Well, 2 problems here:
Performance testing over internet connection is absolutely pointless. You don't know what is between you and servers, and how those things in between are changing the shape of the load. You won't know if it was 10K concurrent requests, or 10K sequential requests. And results will only tell you how fast your internet is.
Any ISP will have a limit on number of connections from one IP, and it will be well below 10K. Not to mention that some ISPs may flag / temporary ban your IP for such flood.
Bottom line: whoever asked you to test 10K or 200K concurrent users, should also provide a set of JMeter machines to run this test from. Those machines should be close to tested servers, preferably without any extra routing in between (or with well known and well configured routing)
I don't think that stressing your application by kicking off 200k users at once is a good idea (same applies to 10k users) as the results, even in case of success, won't tell the full story. Moreover, in case of error you will be able to state only that 10k users in 10 seconds is not possible, however you won't have the information like:
What was the number of users when errors start occurring
What is the correlation between number of concurrent users and response time and/or throughput
What is the saturation point (the maximum system performance)
So I would recommend re-running your test and increasing the load gradually from one virtual user to 10 000 and see when it breaks. The breaking point is called bottleneck and the cause can be determined like:
First of all make sure you're following JMeter Best Practices as default JMeter configuration is not suitable for high loads and if JMeter is not capable of sending requests fast enough you will not get accurate results. Most probably you will have to run JMeter in Distributed mode, it is highly unlikely you will be able to mimic 20k requests per second from a single machine (or it has to be a very powerful one)
Set up monitoring of the application under test in order to ensure that it has enough headroom in terms of CPU, RAM, Disk, etc. You can use JMeter PerfMon Plugin for this
Check your application infrastructure, like JMeter the majority of middleware components like web/application servers, load balancers, databases, etc. default configurations are suitable for development and debugging, they need to be tuned for high throughput.
Check your application code using profiler tools telemetry, the reason could be in i.e. slow DB query, inefficient algorithm, large object, heavy function, etc.
I would like to measure loading time of a document in my testing web app. I have used JMeter for this, but I am getting different values for each run. I am measuring average time in the summary report.
I am not sure, that the value is proper or not.Is this approach is correct or Is there any plugin JMeter available?
I have used HTTP watch to get rendering time, but I can't use that tool for more than 1 user (Load Testing). I am using JMeter 2.13. Could you please help me in this?
With the help of aggregate report or csv / xml results you get required information regarding response times BUT
In Jmeter, Response time = Processing time + Latency(time taken by network while transferring data)
In Browser, Response time = Processing time + Latency + Rendering time
Hence you will found a difference between http watch response times and jmeter response times.
If you need to include rendering times also in your response times, then use tools, like loadrunner (commercial), selenium (open source) and so on. Personally in my opinion client side rendering is not a measurable value, unless all of the users accessing the application are having same configuration of hardware, software and network access. However, while JMeter test running with peak load to the system, manually browse the site using various browsers and with the help of developer tools you can find rendering times.
I am getting different values for each run - this will depends upon test data you are using, server health status, network delays and so on.
I doubt you'll be able to get 2 fully identical test run results, there always will be some form of fluctuation caused by underlying hardware and software implementations. You should be receiving similar results with some statistical noise.
If this is not the case, your JMeter test might be misconfigured. From "realness" perspective mind the following configuration:
Make sure you have Retrieve All Embedded Resources from HTML Files box checked and you Use concurrent pool. The easiest way to configure it for all the samplers is using HTTP Request Defaults
Add HTTP Cache Manager to your test plan. Previous setting "tells" JMeter to fetch embedded resources like scripts, styles, etc. from the pages. Real browsers do it as well but they do it only once, on subsequent requests these resources are being returned from browser's cache.
Add HTTP Cookie Manager to your test plan. It represents browser cookies, enables cookie-based authentication and maintains sessions.
Add HTTP Header Manager to represent browser headers like User-Agent, Content-Type, encoding, etc.
When you use a straight HTTP Protocol layer virtual user, independent of the tool (Jmeter, LoadRunner, SOASTA, Grinder, ...) then what you will be timing will be the request/response information coming from the server with very low coloration from the local processing on the client for JavaScript and the final "drawing on the screen" which is rendering.
Up until the point where the server is degraded due to number of requests or network limitations the only area where you can tune is in the page architecture, which if you are waiting to the last 100 yards before deployment to address then you are likely in trouble.
Steve Souders has written quite a bit on the subject of page architecture in his books "High Performance Websites" and related works. In short, the rule of thumb comes down to making fewer requests, smaller responses and serving the data from the closest possible location to the client. These have the effect of minimizing the most expensive finite resource to a web client, the network. For instance, a browser sprite reduces the number of calls for images, minification and compression reduce the size of the transmission and a CDN changes the number of hops to the requested item to a location closer to the end client.
In order to affect changes to page architecture you need to move upstream into your development cycle and your functional testing cycle. You will need to work with development to implement hard gates where code/pages cannot be submitted to the project without first passing performance gates related to design. Your development team and functional testing members will need to respect those gates. As to what the gates should be, I refer you back to the works of Mr Souders as a great source of data for construction of your gate rules.
This gets you to the level of "works for one: Performant for one." Then you can use that as a known good to answer the questions related to server scalability and at which point the service to the client from requests begins to degrade. If you have a CDN in your organization, be sure to take that into account in your test model, for if you do not then you will overload your server vs production.
As far as actual speeding of the "rendering" or drawing on the screen? You need to purchase a faster video card barring changes from the browser manufacturer. Speeding up JavaScript? Make sure that all of your JavaScript is as small and as lean as possible. Have your functional test team test on very dirty browsers with lots of add-ins as well as lower powered hardware for a view of maximum out of spec response. If you need a view of what your standard hardware model looks like from your clients (Browser/OS/some hardware into) then you can process the data in your HTTP request logs and specifically the user agent related to client configuration information.
Our client asked us to run a stress test on their Web application simulating 62,000 users (threads), the test consists of 13-15 HTTP requests, with 1 second delay between every HTTP request, the test should run for 10.5 hours continuously.
I had previous experience with JMeter running up to 10,000 users, but have not tried for larger number.
Is there a limit for the number of threads that JMeter can handle, or is this limited by the hardware of test server?
agreed with Ray when you run jmeter for this much amount of thread the distributed testing is the best option, and the hardware and network shall be capable to handle this kind of load, and in case you want to do that in short go for http://blazemeter.com, they are Scalable from 1,000 to 100,000 concurrent users.
In principle it is limited by several factors including the configuration (CPU/Mem) of your JMeter machine. That said, it is a VERY large number of threads for just one JMeter. To be honest: I wouldn't run even 10000 threads on one machine. You might want to look into using JMeter distributed, see the manual (http://jmeter.apache.org/usermanual/jmeter_distributed_testing_step_by_step.pdf).
Except running script remotely, you'll need to configure your script with minimal usage of CPU and memory.
Use JMeter best practices and JMeter tuning tips to reach it
I'm planning to do a load test of our ASP/.NET web application and need to simulate about 600 concurrent users on our system.
Initially we'll just be running the load test tools (probabaly JMETER or WCAT/WAST) from our personal workstations which are Windows 7/32 Bit Dells (Dual Core processors). I was wondering about how many users I can expect to be able to simulate from one client.
If I can easily do 200 users per client, I'll need to identify 2-3 more clients for the test.
I wanted to ask the community based on their experience how many users I should expect per client on a standard windows box.
Any help is appreciated!
This highly depends on the test plan itself and cannot be answered that easily.
If you for example have 500 users that just do one request and then have a waiting timer for five minutes, this should work. If all users constantly do requests without waiting, this will put much more load on your machine.
It depends on the samplers in use. HTTP requests are less costly than SOAP requests for example.
It also depends on the listeners you have active.
For a normal load test I usually have around 100-300 threads active. I would suggest to start with such a number and to monitor the load (CPU, network) on your client to see how much potential there is.
Without more details about the test scenarios and the hardware, it is hard to give specific answers. But our Load Tester product can (usually) handle this level of users pretty easily on a single machine (assuming relatively modern hardware). The testing tool should scale linearly up to a point, so you should be able to get a good estimate by running 50 users through a scenario that is similar to what you expect to test.