测量分布式应用程序的内存使用量

Question

What is the best way to measure memory usage of a distributed application?

I'm not sure if using ps on each machine is the best approach on this problem -- the saner the solution, the better (:

PS: The application is in c++ , and is to be executed using linux .

Answer 1

Install one of several really good open source enterprise datacenter monitoring tools. Good ones are:

• Hyperic
• Nagios

These are terribly easy to install and give you not only memory but also any other system property you could shake a stick at.

Answer 2

To get memory usage programmatically, read from /proc/self/statm :

#include <fstream>
#include <iostream>

int main()
{
        std::ifstream statm("/proc/self/statm");
        size_t mem_virt, mem_rss, mem_shared;
        statm >> mem_virt >> mem_rss >> mem_shared;
        std::cout << "Memory stats:" << std::endl <<
                     "Virtual memory size:  " << mem_virt   << std::endl <<
                     "Resident memory size: " << mem_rss    << std::endl <<
                     "Shared memory size:   " << mem_shared << std::endl;
        return 0;
}

I guess you mostly interested in resident memory size , that is, how much RAM is accessible to the program right now. See an answer from ServerFault which describes the meaning of these three types.

Answer 3

I would suggest to implement simple logic in separate thread of your application. That will sleep most of time, wake up once in couple of minutes, call mallinfo and put that data to log or network.

Answer 4

There's a memory checker app called alleyoop (which uses the valgrind lib) that can monitor a program. I recommend checking this out: http://alleyoop.sourceforge.net/

Answer 5

You can use

cat /proc/PROC_PID/smaps 

in order to get the detail of all the memory pages used by your process. However, you don't have the indication whether the memory is really used or just reserved. There is also

pmap -x PROC_ID, doing similar work.

Finally, there is

cat/proc/PROC_ID/status | grep Vm 

giving you informations about all memory types used by your program.