Testing RTMP Live Streaming with Flazr In this test we want to load test a Wowza origin server itself to see the direct effect of a lot of users on CPU load and RAM usage. This test is performed with Flazr, via RTMP on port 1935. First published on MSDN on Aug 01, 2018 Authored by Edwin Hernandez In this post, we would like to talk about Performance Testing Tools. The market for Performance Testing has evolved over time with some newcomers and also test tools that have been around for 10-20 years and have been updating their features to rise up to the challenges of modern applications. StreamTest load testing supports RTMP. For further details, see our full FAQ. What do I need to start my load test? To start a LoadTest you will need to provide a compatible streaming link, the number of test users required, the bitrate of your stream, and the locations to test from. For more information, see the full FAQ. Will the load testing.
Even the most novice among website owners has at some point or other tested their website performance. However, most of these tests normally focus on loading speed or user experience indices.
But what about load testing?
Although most websites are prone to traffic levels that are usually quite regular, there may be occasions when some sites will have to deal with heavy loads. Examples of these include online stores, or even some government websites.
Rtmp Url
If your website gets an unexpected spike in the number of visitors over a short period, how well are you equipped to handle it?
Understanding Load Testing
What is load testing?
Load testing is bench-marking a website to see how it performs under various loads.
For example, a test may simulate an increasing number of concurrent visitors landing on your site. It will also record how your site handles them and records them for your reference.
What types of “load” are tested?
Depending on the tool you choose to load test your site with, each may come with different features. The most basic will simply involve simulating an ever increasing load and halting when your site crashes.
Other tools may be capable of generating a simulated load that mimics different user behaviour, such as performing queries, changing pages, or loading other functions. Some may even be able to map out logical flows for each individual scenario.
Load Testing Tools to Consider
Depending on their complexity, some load testing tools can be quite expensive. However, there are cheaper options in the market and some are even free for use. I’ve included a mixture of these below for your reference, including a couple of open source options.
1. Loadview by Dotcom Monitor
Price: From $199/mo, free trial available
Loadview is one of the more complete solutions available in the market and today is based on a cloud service model. This means that whatever type of simulation you need from them, you only pay for the service – there is zero investment in hardware or anything else.
Feature wise, Loadview offers a very complex solution that can include anything from straight up HTTP load tests to a sophisticated mix of your choice. It is able to simulate dynamic variables and even geo-location diversity in its tests.
Features
- Post-firewall tests
- Handles dynamic variables
- Detailed waterfall charts
- Load test curves
2. K6 Cloud (formerly Load Impact)
Price: From $49/mo
K6 is a cloud-based, open source load testing tool that’s provided as a service. One of the things that makes this tool interesting is that it is priced on a variable-use model which means that the cost of entry can be relatively low depending on your needs. It is, however, mainly developer-centric.
Aside from load testing, K6 also offers performance monitoring. Its load testing side is focused on high loads and can handle various modes such as spikes, stress testing, and endurance runs.
*K6 does not run in browsers nor does it run in NodeJS
Features
- Developer-friendly APIs.
- Scripting in JavaScript
- Performance monitoring
3. Load Ninja
Price: From $270.73/mo
Load Ninja lets you load-test with real browsers based on recorded scripts and then helps analyze performance results. Its use of real browsers at scale means that this tool helps recreate a more realistic environment and end result for testing.
Results can be analyzed in real-time and thanks to the handy tools the system provides, your scripting time can be reduced by as much as 60%. Internal applications can be tested as well, both with proxy-based fixed IPs or your own range of dynamic IPs (by using a whitelister).
Features
- Test with thousands of real browsers
- Diagnose tests in real-time
- Insights on internal application performance
4. LoadRunner by Micro Focus
Price: From $0
With an entry-level free community account that supports tests from 50 virtual users, LoadRunner is available even to the newest website owners. However, if you scale it up to high levels the cost rises exponentially.
This Cloud-based service also offers the use of an Integrated Development Environment for unit tests. It supports a wide range of application environments including Web, Mobile, WebSockets, Citrix, Java, .NET, and much more. Be aware that LoadRUnner can be pretty complex and has a steep learning curve.
Features
- Patented auto-correlation engine
- Supports 50+ technologies and application environments
- Reproduces real business processes with scripts
5. Loader
Price: From $0
Rtmp Load Testing Tool Comparison Chart
Compared to what we’ve shown so far, Loader is a much simpler and more basic tool. Its free plan supports load testing with up to 10,000 virtual users which is enough for most moderate traffic websites.
Unfortunately you will need to have a paid plan to access more advanced features such as advanced analytics, concurrent tests, and priority support. It is easy to use though since basically you just add your site, specify the parameters, then let the test run.
Features
- Shareable graphs & stats
- Useable in a GUI or API format
- Supports DNS Verification and priority loaders
6. Gatling
Price: From $0
Gatling comes in two flavors, Open Source or Enterprise. The former lets you load-test as an integration with your own development pipeline. It includes both a web recorder and report generator with the plan. The Enterprise version has on-premise deployments or alternatively, you can opt for a Cloud version based on Amazon Web Services (AWS).
Although both of these versions are feature-packed, the Enterprise version supports a few extras that don’t come with Open Source. For example, it has a more usable management interface and supports a wider range of integrations.
Features
- Multi-protocol scripting
- Unlimited testing and throughput
- Gatling scripting DSL
7. The Grinder
Price: From $0
Grinder is open sourced all the way and is probably the only truly free option on this list. However, it has to be run locally in your own development environment and needs a few extra such as Java in order to work.
However, being open source it has been adopted widely and developers have come up with a plentiful number of plugins which vastly extend it in terms of both use-ability and functionality. Still, unless you’re a developer or so oriented, The Grinder might be a bit of a handful for you to use.
Features
- Flexible scripting based on Jython and Clojure
- Highly modular with tons of plugins
- Distributed framework and mature HTTP support
Rtmp Load Testing Tool Kit
When to Load Test Your Website?
If you’ve had a look at most of the tools available, you will probably have noticed that many of them offer either trial accounts or some form of limited free version. This makes them readily available for use for a wide audience.
Most website owners need to be concerned about hosting performance since it affects far more than simply user experience. For many business owners, the availability of your website is also a matter of brand reputation.
Sites which are growing need to be especially cautious of availability and scalability of the resources used to hosting your website. In most cases a high percentage of user response time is spent on the surface of your site. However, as sites grow in traffic volume this might change.
More traffic usually means a disproportionate growth in backend processing and your system will struggle as that spikes. Much will depend on variables unique to your site development, so it isn’t possible to give you a solid number of visitors at which point this will happen.
To realistically see how your site performance you need load testing to be done. Exactly when to do it is debatable, but my advice would be to plan ahead and test early.
What to Check for When Load Testing?
As the very name implies, your core function should be the basic of how your site performs under loads. This will let you observe a number of things such as:
- At what point your site performance starts to degrade
- What actually happens when service degrades
When I mentioned how different sites may react differently based on their architecture, that was a signal meant for you to understand that not all sites fail in the same way as well. Some database-intensive sites might fail on that point, while others may suffer IO failures based on server connection loads.
Because of this, you need to be prepared to set up a variety of tests to understand how your site and server will cope under various scenarios. Based on those, keep a close eye on a few key metrics such as your server response time, the number of errors cropping up, and what areas those faults may lie in.
Generating complex scripts and runs along with the accompanying logic can be difficult. I suggest that you approach load testing incrementally. Start with a brute force test that will simply test your site under a continuously increasing stream of traffic.
As you gain experience, add on other elements such as variable behaviour, developing your scripts and logic over time.
Conclusion: Some is Better than None
When it comes to load testing, starting with the basics is better than not getting started at all. If you’re a beginner to all of this, do try to do your testing on an alternate mirror or offline where possible – avoid load testing a live site if you can!
If you’re just starting out now, make sure to create a record of your tests. Performance testing is a journey that should accompany the development of your site as it grows. The process can be tiring but remember, not having a record can make future assessments much more difficult for you.
There are two types of test I’ll describe below. First of all using Apple HLS streams, which is HTTP Live Streaming via port 80, supported by iOS and Safari, and also by Android (apps and browser). Then we have Adobe’s RTMP over port 1935, mostly used by Flash players on desktop, this covers browsers like Internet Explorer and Chrome on desktop. These tests apply to Wowza server but I think it’ll also cover Adobe Media Server.
All links to files and software mentioned are duplicated at the end of this post.
It’s worth noting that you can stick to HLS entirely by using an HLS plugin for Flash video players such as this one, and that is what we’re doing in order to make good use of Amazon’s CloudFront CDN.
For the purpose of testing you may also wish to simulate some live camera streams from static video files, see further down this post for info on how to do that on your computer, server or EC2.
Testing RTMP Live Streaming with Flazr
In this test we want to load test a Wowza origin server itself to see the direct effect of a lot of users on CPU load and RAM usage. This test is performed with Flazr, via RTMP on port 1935.
Assuming you’ve set up your Wowza or Adobe Media server already, for example by using a pre-built Wowza Amazon EC2 AMI. We’re using an m3.xlarge instance for this test as it has high network availabilty and a tonne of RAM – and we’re streaming 4 unique 720p ~4Mbit streams to it, transcoded to multiple SD and HD outputs (CPU use from this alone is up to 80%).
Installing flazr
First up, for the instance size and test configuration I’m using I modified flazr’s client.sh to increase the Java heap size to 8GB, otherwise you run out of RAM. Next up FTP and upload (or wget) flazr to a directory on your server/EC2 instance. Then SSH in and:
The order of parameters does seem to matter in later versions of flazr, but either way this test runs for 60 seconds, with a load of 1000 viewers. Given all the transcoding our CPU was already feeling the pain, but there was no sign of trouble. We managed 4500 before anything started to stutter in our test player from another m3.xlarge instance.
Of course this only matters if you are not using a CDN, but it’s good to know this EC2 instance can handle a lot of HD viewers.
Testing HLS Live Streaming (or a CDN such as Amazon CloudFront) with hlsprobe
Onto HLS streaming, the standard for mobile apps and sites. We have used Wowza CloudFront Formations to set up HLS caching for content delivery, so that we can handle a very large number of viewers without impacting on the CPU load or network throughput of the origin server, and to giver us greater redundancy. Given CloudFront works with HLS streams we are not using RTMP for this test, so we cannot use Flazr again. To test HLS consumption –that being the continuous download of .m3u8 files and their linked .ts video chunks– we can use a tool called hlsprobe, which written in python.
If you’re on a Mac and don’t have python I recommend you install it via brew to get up and running quickly. If you don’t have brew, get it here.
hlsprobe also relies on there being an SMTP server running, not that you need a fully functional one but:
Then to install hlsprobe’s dependencies and hlsprobe itself:
A sample config is linked at the end of the post.
Running hls probe is as simple as this (note the -v verbose mode, you can turn that off once you have it working).
Now if you fire up the Wowza Engine Manager admin interface, you should still see the connection count and network traffic, but the traffic. If you’re testing your CDN such as with CloudFront, you should note that your CPU usage does not increase substantially as you add thousands of clients.
Simulating cameras to Wowza via nodeJS
It’s good to be able to simulate live streams at any time, either from your computer or in my case, from some EC2 instances. To do this I’ve written a simple nodejs script which loops a video, optionally transcoding as you go. I recommend against that due to high CPU use and therefore frame-loss; in my sample script I am passing through video and audio directly, the video is already using the correct codecs, frame size and bitrate via Handbrake.
The script runs ffmpeg, so you’ll need to install that first:
Edit the js script to point to your server, port, and video file, the run the script with:
If the video completes, it’ll restart the stream but there will be a second of downtime, some video players automatically retry, but make sure your video is long enough for the test to be safe.
These are just a couple of ways of load testing a live streaming server, there are 3rd parties out there but we’ve not had great success so far, and this way you have a lot more control over the test environments.
Links
Rtmp Load Testing Tool Boxes
fakestream.js – NodeJS script to simulate live streams
config.yaml – Sample config for hlsprobe
hlsprobe – Tool for testing HLS streams
Flazr – Tool for testing RTMP streams
OSMF-HLS – OSMF HLS Plugin to support HLS in Flash video players