I'm doing performance testing of a native application on Windows and I need to calculate how much more internet traffic new application version produce compared to previous version. Because application is meant to be working in environment with limited internet connection.
Fiddler displays only HTTP and FTP requests and only those that were sent through proxy. In theory application can ignore proxy and use other protocols or sockets.
Resource Monitor seems to contains only average network activity for last minute (Total B/sec). It is not enough for me because network traffic produced by application is not constant.
Network-related performance counters doesn't contain no relevant counters to look at.
TCPView for some reason do not show information for some processes. It display traffic for specific connection rather than application and when connection is closed information is lost.
After more detailed research I found that Sysinternals Process Explorer looks like appropriate tool for internet traffic estimation. You can add Network Send Bytes and Network Recieve Bytes columns to processes table and manually calculate their values difference at the time range boundaries that you are interested in. In order to this to work you need to start Process Explorer as administrator.
My area recently got 4g internet and it has sped things up to much. Yes, you read right, I want to be able to slow down my browser so that I can watch websites loading. Both for testing my own site so that I can see what other people with slower connections see. Plus I have found that with a lot of sites what I want to see is at the top, so with a slower connection when what I want to see has loaded I can stop downloading the rest of the site and save some of my bandwidth for other things.
Is there a program, or add-on for Firefox that would allow me to do such a thing? If I have to I could limit the connection its self. I am on a window 7 machine with Verizon mobile broadband that plugs into a flash drive.
You can use chrome to simulate internet speed directly.
See this: https://developers.google.com/web/tools/chrome-devtools/network-performance/network-conditions
You can use Fiddler and it's feature Simulate modem speed.
Main menu -> Rules -> Performance -> Simulate Modem Speeds
Here is what I found in:
http://www.charlesproxy.com/documentation/proxying/throttling/
"Charles can be used to adjust the bandwidth and latency of your Internet connection. This enables you to simulate modem conditions using your high-speed connection.
The bandwidth may be throttled to any arbitrary bytes per second. This enables any connection speed to be simulated.
The latency may also be set to any arbitrary number of milliseconds. The latency delay simulates the latency experienced on slower connections, that is the delay between making a request and the request being received at the other end"
There are couple of tools in the market which can throttle your network speed both uplink and downlink. http://bandwidthcontroller.com/trafficShaperXp.html is one such tool. There are couple of others as well. We generally do it via shunra emulator.
Background
I want to create a test application to test the network performance of different systems. To do this I plan to have that machine send out Ethernet frames over a private (otherwise non-busy) network to another machine (or device) that simply receives the message and sends it back. The sending application will record total roundtrip time (among other things).
The purpose of the tests is to see how a particular system (OS + components etc.) performs when it comes to networking traffic. This is illustrated as machine A in the picture below. Note that I'm not interested in the performance of the networking infrastructure (switches, cables etc) - I'm trying to test the performance of network traffic inside Machine A (i.e from when it hits the network card until it reaches user space)
We will (try to) measure all kind of things, one thing is the total roundtrip of the message but also things like interrupt latency of Machine A, general driver overhead etc. Machine A will be a real-time system. But to support these tests, I need a separate machine that can bounce back messages and in other ways add network stimuli to the tested system. This separate machine is Machine B in the picture below and is what this question is about.
My problem
I want to develop an application that can receive and return these messages with as consistent (and preferably low) latency as possible. I'm hoping to get latencies that are consistent within a few microseconds at least. For simplicity, I'd like to do this on a general purpose OS like Windows or Linux but I'm open for other suggestions. There will be no other load (CPU or otherwise) on the machine besides the operating system and my test application.
I've thought of the following approaches:
A normal application running in user space with a high priority
A thread running in kernel space to avoid the userspace/kernelspace transitions
An of-the-shelf device that already does this (I haven't found one though)
Questions
Are there any other approaches or perhaps frameworks that already does this? What else do I need to think of to gain a consistent and low latency? What approach is recommended?
You mentioned that you want to test the internal performance of Machine A, but "need a separate machine"; yet, you don't want to test network infrastructure performance.
You know much more about your requirements than I do; however, if I was testing network infrastructure in Machine A, I would set up my test like this:
There are couple of reasons for this:
You can use an Ethernet loopback cable to simulate the "pong" function performed by Machine B
Eliminating transit through infrastructure you don't care about is almost always a better solution when measuring performance
If you use this test method, be sure to note these points:
Ethernet performs a signal to noise test on the copper before it sets up a link. If you make your loopback bends too tight, you could introduce more latency if ethernet decides to fall back to a lower speed due to the kinks in the cable. There is no minimum length for copper ethernet cabling.
As you're probably aware, combinations of NICs / driver versions / OS can have a significant affect on intra-host latency. I work for a network equipment manufacturer, and one of the guys in the office used to work as an applications engineer for SolarFlare. He claims that many of the Wall Street trading systems use SolarFlare's NICs due to the low latency SolarFlare engineers their products for; he also said SolarFlare's drivers give you user-space access to the NIC buffers. Caveat: third-hand info, and I cannot verify myself.
If you loop the frames to Machine A, set the source and destination mac-address to the burned-in-address on the NIC
Even if you need to receive a modified "pong" frame from Machine B, you could still use this topology and simply rewrite packet fields on the receive-side of your code in Machine A. Put as many (or few) instrumentation points as you like in Machine A's "modules" to compare frame timestamps.
FYI:
The embedded systems I mentioned in my comments on your question are for measuring latency of network infrastructure, not end hosts. This is the best method I can think of for instrumenting host latency.
As an off the shelf solution, I would suggest taking a look at Solace, Tibco and AMQP. These are all enterprise messaging frameworks used extensively in trading applications. AMQP is open source and capable of handling throughputs of up to 100,000 messages per second. I am not sure of the latencies of other frameworks. There is a Java or C++ implementation of the AMQP message router. The C++ one of course returns higher performance.
Edit I've just heard of a new product called UltraMessaging which can provide 7,000,000 messages per second throughput with Java, C++ or C# clients. Crikey.
Best regards,
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I know this is kind of an odd question. Since I usually develop applications based on the "assumption" that all users have a slow internet connection. But, does anybody think that there is a way to programmatically simulate a slow internet connection, so I can "see" how an application performs under various "connection speeds"?
I'm not worried about which language is used. And I'm not looking for code samples or anything, just interested in the logic behind it.
Starting with Chrome 38 you can do this without any plugins. Just click inspect element (or F12 hotkey), then click on "toggle device mod" and you will see something like this:
Among many other features it allows you to simulate specific internet connection (3G, GPRS)
P.S. for people who try to limit the upload speed. Sadly at the current time it is not possible.
P.S.2 now you do not need to toggle anything. Throttling panel is available right from the network panel.
Note that while clicking on the No throttling you can create your custom throttling options.
If you're running windows, fiddler is a great tool. It has a setting to simulate modem speed, and for someone who wants more control has a plugin to add latency to each request.
I prefer using a tool like this to putting latency code in my application as it is a much more realistic simulation, as well as not making me design or code the actual bits. The best code is code I don't have to write.
ADDED: This article at Pavel Donchev's blog on Software Technologies shows how to create custom simulated speeds: Limiting your Internet connection speed with Fiddler.
Google recommends:
Network Link Conditioner on OSX
Clumsy on Windows
Dummynet on Linux
On Linux machines u can use wondershaper
apt-get install wondershaper
$ sudo wondershaper {interface} {down} {up}
the {down} and {up} are bandwidth in kpbs
So for example if you want to limit the bandwidth of interface eth1 to 256kbps uplink and 128kbps downlink,
$ sudo wondershaper eth1 256 128
To clear the limit,
$ sudo wondershaper clear eth1
I was using http://www.netlimiter.com/ and it works very well. Not only limit speed for single processes but also shows actual transfer rates.
There are TCP proxies out there, like iprelay and Sloppy, that do bandwidth shaping to simulate slow connections. You can also do bandwidth shaping and simulate packet loss using IP filtering tools like ipfw and iptables.
You can try Dummynet, it can simulates queue and bandwidth limitations, delays, packet losses, and multipath effects
Use a web debugging proxy with throttling features, like Charles or Fiddler.
You'll find them useful web development in general. The major difference is that Charles is shareware, whereas Fiddler is free.
Also, for simulating a slow connection on some *nixes, you can try using ipfw. More information is provided by Ben Newman's answer on this Quora question
You can use NetEm (Network Emulation) as a proxy server to emulate many network characteristics (speed, delay, packet loss, etc.). It controls the networking using iproute2 package and it's enabled in the kernel of most Linux distributions.
It is controlled by the tc command-line application (from the iproute2 package), but there are also some web interface GUIs for NetEm, for example PHPnetemGUI2.
The advantage is that, as I wrote, it can emulate not only different network speeds but also, for example, the packet loss, duplication and/or corruption, random or defined delay, etc., so apart from the slow connections, you can also emulate various poorly performing networks and transmission errors.
For your application it's absolutely transparent, you can configure the operating system to use the NetEm as a proxy server, so all connections from that machine will be routed through it. Or you can configure only a specific application to use that proxy.
I have been using it to test the performance of an Android app on various emulated poor-performance networks.
Use a tool like TCPMon. It can fake a slow connection.
Basically, you request it the exact same thing and it just forwards the exact same request to the real server, and then delays the response with only the set amount of bytes.
For Linux, the following list of papers might be useful:
A Comparative Study of Network Link Emulators (2009)
KauNet: A Versatile and Flexible Emulation System (2009)
Dummynet Revisited (2010)
Measuring Accuracy and Performance of Network Emulators (2015)
Personally, whilst Dummynet is good, I find NetEm to be the most versatile for my use-cases; I'm usually interested in the effect of delays, rather than bandwidth (i.e. WiFi connection issues), and it's super-easy to emulate random packet loss/corruption, etc. It's also very accessible, and free (unlike the hardware-based Linktropy).
On a side-note, for Windows, Clumsy is awesome. I would also like to add that (regarding websites) browser throttling is not an accurate method for emulating real-life network issues (I think "TKK" commented on a few of the reasons why above).
Hope this helps someone!
One common case of shaping a single TCP connection can actually be assembled from dual pairs of socat and cpipe in UNIX fashion like this:
socat TCP-LISTEN:5555,reuseaddr,reuseport,fork SYSTEM:'cpipe -ngr -b 1 -s 10 | socat - "TCP:localhost:5000" | cpipe -ngr -b 1 -s 300'
This simulates a connection with bandwidth of approximately 300kB/s from your service at :5000 and to at approximately 10kB/s and listens on :5555 for incoming connections. Caveat: Note that this per-connection, so each individual TCP connection gets this amount.
Explanation:
The outer (left) socat listens with the given options on :5555 as a forking server. The first cpipe command in the SYSTEM:... option then throttles data that went into socket :5555 (and comes out of the first, outer socat) to at most 10kByte/s. That data is then forwarding using another socat which connects to localhost:5000 (where the service you want to slow down should be listening). Data from localhost:5000 is then put into the right cpipe command, which (with the given values) throttles it to about 300kB/s.
The option -ngr to cpipe is important. It causes cpipe to read non-greedily from its input file-descriptor. Otherwise, you might get stuck with data in the buffers not being forwarded and waiting for a reply.
Using the more common buffer tool instead of cpipe is likely possible as well.
(Credits: This is based on the "double-tee" recipe by Christophe Loor from the socat documentation)
Mac OSX since 10.10 has an app called Murus Firewall, which acts as a GUI to pf, the replacement for ipfw.
It works very well for system-wide or domain-specific throttling. I was just able to use it to slide my download speed between 300Kbps and 30Mbps to test how a streaming video player adjusts.
Updating this (9 years after it was asked) as the answer I was looking for wasn't mentioned:
Firefox also has presets for throttling connection speeds. Find them in the Network Monitor tab of the developer tools. Default is 'No throttling'.
Slowest is GPRS (Download speed: 50 Kbps, Upload speed: 20 Kbps, Minimum latency (ms): 500), ranging through 'good' and 'regular' 2G, 3G and 4G to DSL and WiFi (Download speed: 30Mbps, Upload speed: 15Mbps, Minimum latency (ms): 2).
More in the Dev Tools docs.
There is also another tool called WIPFW - http://wipfw.sourceforge.net/
It's a bit old school, but you can use it to simulate a slower connection. It's Windows based, and the tool allows the administrator to monitor how much traffic the router is getting from a certain machine, or how much WWW traffic it is forwarding, for example.
There is a simple and practical way to do it, without any application or code. Just connect to the internet using a mobile hotspot. Keep moving the hotspot (phone) away from the connected device to simulate slower networks. 😉
I am doing networking project, My current broadband internet speed is 2Mbps my application is working correctly. I need to test my application status 512Mbps or any other speed.
How to decrease the speed of internet, Is there any way to increase/decrease the speed by making changes in local machine.
Thanks.
http://netlimiter.com/ our perf team use this very successfully to simulate the real world comms situations. It costs but for a single seat its < 30 US
Fiddler is a free alternative. It's bandwidth limiter can break https in my experience. Oh, and it only works with http connections. But, free so...