bandwidth

I have a server with OpenVZ installed and virtual machines with a public IPv4 for every machine. I need to get the bandwidth usage of each separate virtual machine (mbps or kbps) from PHP. My idea is to install iftop on the host machine and run it from PHP function exec(), the command "iftop -n -F AA.BB.CC.DD/32". The problem is that is an application iftop "top" style, and is made to run on a real terminal and is updated with new data. I can not install anything on the VMs, should be clean. Nor has a network interface each VM and I can not change it. I wonder what other options I have or how

I write web based applications. Performance is obviously a key factor. Whilst database load and page rendering time are things I have control of, the users internet connection is not. What I'm looking for is a way to indicate what sort of a connection a user has. Something along the lines of a traffic light in the corner of a website that shows the user what sort of a connection they have to the site and therefore indicating what sort of perceived performance they should expect. e.g. Maybe the app just seems slow because everyone else in your company is browsing facebook on their lunch hour.

Nvidia has offered an example about how to profile bandwidth between Host and Device, you can find codes here: https://developer.nvidia.com/opencl (search "bandwidth"). The experiment is carried on in an Ubuntu 12.04 64-bits computer. I am inspecting pinned memory and mapped accessing mode, which can be tested by invoke: ./bandwidthtest --memory=pinned --access=mapped The core test loop on Host-to-Device bandwidth is at around line 736~748. I also list them here and add some comments and context code: //create a buffer cmPinnedData in host cmPinnedData = clCreateBuffer(cxGPUContext, CL_MEM

In push notification mechanisms, like Apple's Push Notification Service, they use persistent IP connections. My question is, how does employing persistent connections save battery and bandwidth of a device? I am under the impression that since the connection is persistent, then the device always uses the WiFi or 3G/LTE radio. I know that through persistent connections, you will not waste bandwidth by not asking the server for changes when there is none, and instead the server will "push" to you these changes. But, I don't see how that preserves battery and bandwidth (since you have an always

I need to test the performance of application running on localhost as if it were in the online environment. I mean the performance test conducted by the network traffic simulation, limited bandwidth simulation, or other parameter as if it were online. Could Apache Ab do the simulation? We've used Charles and Firefox Throttle in the past to simulate slow networks. Yes, but you will need to connect to your application by IP address, not "localhost" or 127.0.0.1. Typically for web applications (HTTP) I use Fiddler which can simulate limited bandwidth, but only if you connect as I have noted.

I have seen a number of questions that don't answer this, is it possible to check someones bandwidth using java script and load specific content based on it? The BBC seem to give me low quality images when using my mobile and in the middle of nowhere. by the looks of this this cool service does this and its a CDN so it could be server side. http://www.resrc.it/docs/ Does anyone know how they do it? or how I could do it using asp.net or javascript, or an community opensource plug in. I think it may be possible with https://github.com/yahoo/boomerang/ but not sure this is its true purpose.

I want to know if there is an efficient solution to monitor a process resource consumption (cpu, memory, network bandwidth) in Linux. I want to write a daemon in C++ that does this monitoring for some given PIDs. From what I know, the classic solution is to periodically read the information from /proc, but this doesn't seem the most efficient way (it involves many system calls). For example to monitor the memory usage every second for 50 processes, I have to open, read and close 50 files (that means 150 system calls) every second from /proc. Not to mention the parsing involved when reading