- Npm Test Command
- Npm Unit Test
- Stress Test Tool Npm Tutorial
- Npm Run Test
- Windows Build Tools Npm
- Npm Test Specific Test
- Stress Test Tool Npm Tool
AIDA64 is a comprehensive system diagnostic tool designed for professionals. It is packed with many unique features and can be used to stress test every PC component, including GPU, CPU, and RAM. AIDA64 has the ability to detect fake NVIDIA graphic cards with counterfeit PCI identifiers and reflashed BIOS images. A command-line tool for simulating any number of clients; A group of computers that will run this tool simultaneously; A method to control those computers from the comfort of your swivel chair/throne/park bench; Now (finally) you’re ready to begin your stress test in earnest. If all this is new to you, you might not have a production server. Tools Reviewers Use to Stress Test CPU; Here, we will list 5 programs that reviewers use for gauging the performance of most computers. However, keep in mind, these are mostly benchmarking programs rather than a true CPU stress testing tool. 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. Loadview by Dotcom Monitor. Later in this unit, I show you how to configure and run the linter as two separate npm scripts in your npm test lifecycle. Set up the example project. So far you’ve had an overview of testing techniques and some of the tools you can use to automate testing in your npm lifecycle. In this section we set up an example project and write a few tests.
This post is the second in a three-part series describing our investigationsinto scalability for a second screen application we built for PBS. You can readthe introduction here.This guide assumes you have a production server up and running. If you needhelp getting there, check out the final post in theseries for a guide toconfiguring a Node.js server for production.
If you read my harrowing tale on stresstesting, you may beinterested in conducting similar research for your own nefarious purposes. Thispost is intended to help others get a leg up stress testing Node.jsapplications–particularly those involving Socket.io.
I’ll cover what I consider to be the three major steps to gettingup-and-running:
- Building a client simulator
- Distributing the simulation with Amazon EC2
- Controlling the simulation remotely
The Client Simulator
The first step is building a simulation command-line interface. I’llnecessarily need to be a little hand-wavy here because there are so many waysyou may have structured your app. My assumption is that you have someJavaScript file that fully defines a Connection constructor and exposes it tothe global scope.
Simulating many clients in Node.js. Lucky for you, Socket.io separates itsclient-side logic into a separatemodule, and this can runindependently in Node.js. This means that you are one ugly hack away from usingthe network logic you’ve already written for the browser in Node.js (assumingyour code is nice and modular):
Now you can instantiate an arbitrary number of connections iteratively. Be sureto spread these initializations out over time, like so:
As I discussed in the previous post in this series, failing to take thisprecaution will result in heartbeat synchronization. I guess that sounds cool,but it can have unpredictable results on your measurements.
If your connection module is using Socket.io’s top-level io.connect methodto initiate a connection, you’ll have to make an additional modification. Bydefault, Socket.io will prevent the simulator from making multiple connectionsto the same server. You can disable this behavior with the 'force newconnection' flag, as in io.connect({ 'force new connection': true });.
The above example makes use of a clientCount variable. This is just onesimulation variable you will likely want to manipulate at run time. It’s agood idea to support command-line flags for changing these values on the fly. Irecommend using the “optimist”library to help build a usablecommand-line interface.
Date collection. For another perspective on test results, you may decide toscript your simulator to collect performance data. If so, take care in themethod of data collection and reporting you choose. Any extraneous computationcould potentially affect the simulator’s ability to simulate clients, and thiswill lead to unrealistic artifacts in your test results.
For example, you may want to store the time that each “client” receives a givenmessage. A naive approach would look something like this:
Most Node.js developers maintain a healthy fear of any function call thatstarts with fs. and ends with Sync, but even the asynchronous version couldconceivably impact your simulator’s ability to realistically model hundreds ofclients:
To be safe, I recommend storing test statistics in memory and limiting thenumber of disk writes. For instance:
Now, you could have the simulator periodically write the data to disk andflush its in-memory store:
…but you still run the risk of simulation artifacts from conducting I/Ooperations in the middle of the procedure. Instead, consider extending yoursimulator to run a simple web server that responds to HTTP GET requests by“dumping” the data it has collected:
This approach allows for a clean separation of data gathering and datareporting. You can run your simulation for some period of time, pause it, andthen run the following command to get at your statistics:
Of course, this also introduces the overhead of running a web server. You willhave to weigh this against the performance impact of immediate I/O operations,and this is largely dependent on the amount of data you intend to collect (bothin terms of size and frequency).
Scripting clients. In some cases, having “dumb” clients that merely connectand wait for data will be enough to test the system. Many applications includecomplex client-to-client communication, so you may need to script more nuancedbehavior into the simulator. That logic is extremely application-specific whichmeans I get to “leave it as an exercise to the reader” to build a script thatmakes sense for your application.
Although you now have a mechanism to simulate a large number of clients on yourlocal machine, this approach would be far too unrealistic. Any tests you runwill likely be bottlenecked by your system’s limitations, whether in terms ofCPU, memory, or network throughput. No, you’ll need to simulate clients acrossmany physical computers.
Distributing with EC2
Taking a hint from Caustik’swork,I began researching details on using Amazon WebService‘s Elastic Compute Cloud (EC2) to distribute mynew simulation program. As it turns out, Amazon offers a free usage tier fornew users. The program lasts for a year afterinitial sign up and includes (among other things) 750 hours on an EC2 “Micro”instance. This is enough to run one instance all day, everyday, or (moreimportantly) 20 instances for one hour a day. All this means that you can runyour simulation on 20 machines for free!
The first thing you’ll need is an Amazon Machine Image (or “AMI” for short).This is a disk image from which each machine will boot. Amazon hosts an entireecosystem of user-made AMI’s, and you can likely find one that suits yourneeds. I recommend creating your own since it is so easy and you can never besure exactly what might be running on a home-made AMI. Just select a free AMIauthored by Amazon to begin. We’ll be using this as a base to create our owncustom AMI to be cloned as many times as we wish.
You can use many of the AMI’s offered by Amazon at no charge under the AWS freetier.
As part of this process, you will need to create a key pair for starting thisAMI. Hold on to this: you’ll need it to launch multiple instances in the nextstep.
By default, AMI’s do not support remote connections though SSH. This is theunderlying mechanism of our administration method (more on this below), soyou’ll need to enable it. Use the AWS ManagementConsole to create a custom security groupthat allows connections on port 22 (to make this easy, the interface has apre-defined rule for SSH).
In this example, the security group named “bees” has been configured tosupport SSH access.
Next, you’ll want to customize the AMI so that it can run your simulationimmediately after being cloned. You can install Node.js from your operatingsystems software repository, but please note that the version available may bewell behind latest. This has historically been the case with Debian and Ubuntu,for instance, which currently supply version0.6.19 despite the latest stablerelease being tagged at0.8.16. Installing Node.jsfrom source may be your best bet (if you need guidance on that, check out thispage on the Node.js wiki).
While you could use a utility likescp to copy your simulation code tothe AMI, I recommend installing your version control software (you are usinga VCS, right?) and fetching from your repository. This will make it much easierto update the simulation later on.
Currently, your simulation script is likely tying up the terminal. Whenconnected over SSH, this behavior would prevent you from issuing any othercommands while the simulation runs. There are a number of ways you can“background” a process, thus freeing up the command line. Since you havealready installed Node.js, I recommend simply using the “forever” utility fromNodejitsu. Install it globally with:
Now, when connected remotely, you can effectively “background” the followingcommand:
by instead running:
When you’re done, just run:
to cancel the simulator.
Now that you’re able to run the simulation on this customized setup, it’s timeto save it as your own personal AMI. With your EC2 instance running, visitthe EC2 Dashboard and view the running instances. Select the instance you’vebeen working with and hit “Create Image”. In a few minutes, your custom AMIwill be listed in the dashboard, along with a unique ID. You’ll need to specifythis ID when starting all your simulator instances, so make note of it.
Administration
The last step is building a means to administer all those instances remotely.You’ll want to make running a test as simple as possible, and it can certainlybe easier than manually SSH’ing into 20 different computers.
There’s an old saying that goes, “There’s nothing new under the sun.” Besidessounding folksy and whimsical, it has particular relevance in the open-sourceworld: it means that someone else has already done your job for you.
In this case, “someone else” is the fine folks over at the Chicago Tribune.Back in 2010, they released a tool named “Bees with MachineGuns”.This was designed to administer multiple EC2 instances remotely. There’s onecatch, though: it was built specifically for the Apache Benchmark tool.
In order to use it to control your Node.js client simulator, you’ll need a moregeneralized tool. I made a quick-and-dirty fork of theproject to allow forrunning arbitrary shell commands on all the active EC2 instances (or inbeeswithmachineguns lingo, “all the bees in the swarm”). I’m no Pythonista,though, and I encourage you to fork it and help me clean itup!
There are a number of flags you will need to specify in order to get your beesoff the ground. These include the key pair for your custom AMI and the name ofthe custom security group you created. Type bees --help for details.
Here’s an example of how you might start up 10 bees:
Bear in mind that you are on the clock for as long as these instances arerunning, regardless of whether or not you are actually conducting your tests.Even with the free usage tier, you run the risk of being billed forlong-running instances. Once you are finished, do not forget to deactivatethe EC2 instances!
To play it safe, I recommend keeping the EC2 Management Console open duringthis procedure. This lets you keep an eye on all currently-running instancesand can help assure you that yes, they really are all off.
You can invoke your client simulator using the exec command along with theforever utility we built in to the AMI:
And if you ever want to change your simulator logic on the fly, you can use thesame API to pull the latest code:
Just remember that the next time you run your tests, you will bere-initializing machines from your custom AMI, so these on-the-fly patcheswon’t stick.
With Great Power…
Summing up, you now have a complete stress-testing framework ready to go:
- A command-line tool for simulating any number of clients
- A group of computers that will run this tool simultaneously
- A method to control those computers from the comfort of your swivelchair/throne/park bench
Now (finally) you’re ready to begin your stress test in earnest. If all this isnew to you, you might not have a production server to test. Sure, you couldtest your development machine, but we’re striving for realism here. Not toworry: in the final part of this series, I detail my approach to creating aproduction-ready Node.jsserver.
What is network stress testing?
Network stress testing is the practice of putting your network under a heavy load to discover breaking points and areas for improvement.
By using network testing tools, you can determine the limits of your hardware, and help get an understanding of how much traffic you can take on before you need to expand your resources.
Here is our list of the best network stress testing tools for 2020:
- SolarWinds WAN Killer Traffic Generator(FREE TRIAL) – An easy to use and feature-rich toolkit ideal for stress testing the networks of medium to large-sized businesses.
- Nping – Free open-source command-line tool for packet crafting and network testing.
- Packet Sender – Free network stress tester with a graphical interface.
- Ostinato – Provides API integrations, support, and reporting.
- NetScanTools Pro – A bundle of tools that includes a Packet Generator and Packet Flooder to perform stress tests.
Why is network stress testing important?
Network stress testing is important when planning network expansions, as well as when looking to upgrade equipment such as switches and firewalls.
Knowing exactly what your network can and cannot handle will keep you prepared for growth, and help avoid any outages based on hardware limitations. In addition to growth, there are a few other reasons why a business or sysadmin would want to stress test their network.
If you’re an MSP, or service provider that guarantees a certain SLA, you’re going to want to ensure that your network can not only keep your business running but keep your client’s services running as well. Network stress testing can help find unconventional ways end-users could accidentally overload the network and cause service outages that directly impact productivity.
Stress tests can also help identify weaknesses that an attacker could use to overwhelm your infrastructure. DDOS attacks have evolved in complexity over the years, so testing the limits of your network both internally and externally can give you an idea of what it would take to bring down your network.
On the flip side, not all floods of traffic are malicious. In the age of viral content, a successful marketing campaign could drive massive amounts of traffic to a website or service. Not having a plan for these types of events could lose new customers or bring down services that existing customers use in the process.
What causes network stress for businesses?
Network stress can be caused by several factors and can be divided into two segments: internal and external.
Internally on the LAN, most causes of network stress are found to be caused by unregulated traffic taking up too much bandwidth. A great example of this that you may have experienced yourself is when multiple people are streaming Netflix or Hulu and everything grinds to a halt. This can also happen if too many people are moving large files across the intranet or parts of your LAN.
From externally on the WAN, malicious traffic can attempt to overload services that may impact outward-facing products your customers use such as websites and online tools. Attacks could be thwarted with a simple CAPTCHA, but sometimes it’s not that simple. Attackers can create malformed packets and send them to your exposed ports at incredible volumes. Being able to not just stop, but withstand this type of attack is critical for any business that relies on the internet.
How do I fix network stress?
So what can be done to regain control of your network? It all starts with the Quality Of Service (QoS). QoS is available in nearly all-business-class firewalls and routers and allows you to set limits on how much resources a specific source of traffic can use.
Say you’d still like to allow employees to listen to music at work, but don’t want the network getting overloaded by music streaming packets. You can set the QoS to limit music streaming services so that it doesn’t interfere with day to day operations. Ideally, it’s a win-win for everyone. QoS allows you to get as granular as you’d like. You can even set rules based on individual ports and set exclusions based on certain IP addresses.
Of course, all of this would be in vain if you had a legitimate physical bottleneck in your network, like old wiring or a failing switch that brought down your speeds. That’s when running a thorough network stress test can help you map out what parts of your network need improving, and just how much traffic it can take.
How to stress test a network
Stress testing a network can be as simple as sending packets to a machine, or as complex as running an automated tool to report back it’s findings. On a very simple scale running a ping check across your network can give you an idea if a device is dropping packets or experiencing high latency.
For instance, if you know a device is behind a specific firewall or switch, you can ping another device that isn’t behind that switch to help get a better idea of where the bottleneck is coming from. The downside of this is that it’s tedious, and doesn’t provide much insight into what is causing the problem.
Alternatively, you can move a 1GB file across the LAN to another workstation, VLAN or server, and measure the speed. The file size doesn’t have to be 1GB but should be large enough to take some time. This will give you a rough idea of what the speeds are on your LAN to that destination.
A proper network test would involve a bit more detail. With network stress testing tools you can craft specific packets of any size, and control the exact amount of times a device is sent traffic. This level of customization gives you better flexibility.
Most sysadmins will agree that having a proper network stress testing tool saves tons of time, and is a valuable part of their everyday toolkit.
The best network stress testing tools
1. SolarWinds WAN Killer Traffic Generator (FREE TRIAL)
WAN Killer Traffic Generator is one of the many tools you can find in the SolarWinds Engineer’s Toolkit. This tool enables you to go beyond basic stress testing by creating specific packets tailored to your specified protocols inside of any Windows environment.
This opens up near-limitless possibilities when it comes to testing how your servers, applications, and overall network will behave under certain conditions. Through the traffic dashboard, you can control the size, protocol, and destination of your traffic before sending it. This allows you to simulate certain applications, or how your end users are likely to behave in a real-life scenario.
While most network stress testing tools simply blast out traffic, WAN Killer gives you the option to customize traffic patterns to replicate human behavior and set random intervals. This method of testing gives you a more realistic set of data to analyze, and better reflect a live environment.
Npm Test Command
The true value in WAN Killer comes from its ability to mimic your network over time. As you configure WAN Killer you can create traffic patterns that reflect how your network usually functions. As you test new applications you can use this traffic flow as a baseline to better understand how your live environment will react to bandwidth changes and limited network access.
Lastly, WAN Killer gives you tools to measure SLA levels as well as using performance metrics to ensure that not just speeds are met, but that productivity isn’t impacted as well.
You can test out WAN Killer as well as the other 60+ tools in the Engineer’s Toolkit completely free for 30 days.
2. Nping
Nping is an open-source tool used to test response times while targets on a network are under heavy traffic loads. Through a simple command-line interface you can craft packets and set their destination for a wide variety of load balancing and stress testing purposes.
Users of Nping will have full control over every aspect of the traffic sent. Configurations such as custom header, protocol type, size, and speed can all be set up through the terminal interface. Just like WAN Killer, you can specify a target for either multiple hosts or even multiple ports.
In addition to network stress testing, this utility can also prove useful in different security checks as well. Simulate and test for ARP poisoning vulnerabilities by crafting fake ARP messages over your network, or recreate common Distributed Denial Of Service (DDoS) attacks to see how your network holds up.
Nping also comes with an echo mode that gives you a first-hand look at how traffic is changed or manipulated in real-time as it moves through the network. This is an important feature to have, especially if you utilize network address translation across your firewalls or suspect traffic might be getting manipulated.
While Nping is a powerful tool, it does lack official support which is critical for business environments that rely on high up times. There is also no graphical interface for Nping, which could be considered a downside to some sysadmins.
Nping is completely free and available for Windows, Linux, or macOS.
3. Packet Sender
Pack Sender is an open-source packet traffic generator that was developed for testing how networked devices react to specific traffic.
Similar to Nping, Packet Sender can issue multiple types of traffic to any given device, or port on your network and comes with both a command-line interface as well as a GUI. All data can be defined as either ASCII or HEX and this data can be shared either through the Packet Sender Cloud or through an exported report.
While Packet Sender may look simple, it’s still a powerful and free tool that you can use to stress-test your network. Packet Sender is available for Windows, Linux, and macOS.
4. Ostinato
Ostinato is a paid packet sending tool that can be used to stress test devices on your network. Ostinato has a simple and easy to use interface that gives you an overview of your current traffic speeds, volume, port, and device.
On the backend, Ostinato comes with a full API library to allow for integrations into your custom tools or plugins. Traffic tests can be configured to fire randomly, in a pattern, or in a constant stream.
You can set up Ostinato to record data and provide simple reporting on the overall performance or the test, or on how an individual target handled specific traffic. Pricing for Ostinato starts at $19.00 (£14.75) and is available for Windows, Linux, and macOS.
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5. NetScanTools Pro
Last but not least is NetScanTools Pro, which contains a bundle of network testing tools that include a Packet Generator, as well as a Packet Flooder.
Stress Test Tool Npm Tutorial
With Packet Generator, you can craft any type of packets you’d like and send them across your network. You’ll have the full ability to specify how those packets are built, as well as replay captured packets that come across your network. Packets can either be imported from a WinPcap file or captured live on the network in real-time.
The NetScanTools bundle runs on modern Windows environments, is available for testing through a 30-day demo, and starts at $249 (£193.18) per license.
Npm Run Test
Conclusion
Windows Build Tools Npm
We’ve determined that network stress testing is an important part of keeping your environment running smoothly, as well as planning for expansions. So which network stress testing software is right for you?
If you’re managing a medium to large-sized company SolarWinds WAN Killer will give you the best mix of features, ease of use, and support. The ability to craft customized stress tests and produce data-rich reports so conveniently puts WAN Killer at the top of our list.
Npm Test Specific Test
For departments on a budget or home hobbyist networks, Pack Sender is a great free software that will provide plenty of packet crafting and traffic flooding features you’d need to test your environment. The main downside to these free tools is that if you run into a problem, you’re on your own when looking for support.
Stress Test Tool Npm Tool
Do you stress test your network? Do you think it’s an important part of network testing? Let us know in the comments below.