[Lxc-users] Stats 'n' Stuff

[Gordon Henderson]

I'm looking for ways to get stats out of each container on a host - the 
sort of stuff I'm after is the bandwidth of the network interface and cpu 
cycles.

On the CPU monitoring front there is /cgroup/xxx/cpuacct.stat, memory from 
memory.usage_in_bytes and memory.memsw.usage_in_bytes ...

But on the network side...

There is nothing in /cgroup that I can see..

And there seems to be some oddities as the internal interface number is 
created new for each interface - so on the host, eth0 is (typically) 
interface number 2, but in a container it's not 2, but more than 2 - it 
can be found, however the next time you reboot the container or host, it 
will change (or it's highly probable that it will change)

So even if I ran snmp in each container, using something like mrtg to get 
the stats is going to be problematic as you need to encode the interface 
number in the mrtg config file...

In any case, I'd really rather only run one snmpd on the host... The same 
down-side applies in that the interface number changes every time you 
restart a container..

Has anyone worked round this?

My thoughts are that every time I start/stop a container or reboot the 
host, to run mrtgs 'cfgmaker' program then parse the output, matching the 
interface name to the container name (fixing the vethxxxx interface name 
in the containers config file so I know which is which) then extracting 
the network interface, dynamically writing an mrtg.cfg file, then running 
mrtg...

e.g.

   # cfgmaker public at localhost | grep 'Interface.*veth'
   ### Interface 6 >> Descr: 'vethdU4ae6' | Name: 'vethdU4ae6' | Ip: '' | Eth: '4a-d4-c2-97-a9-c0' ###
   ### Interface 10 >> Descr: 'vethr3M2xv' | Name: 'vethr3M2xv' | Ip: '' | Eth: '76-9a-d2-be-a2-50' ###
   ### Interface 14 >> Descr: 'vethiPsSOE' | Name: 'vethiPsSOE' | Ip: '' | Eth: '9e-da-70-6c-b1-93' ###
   ### Interface 18 >> Descr: 'vethQ6lLx8' | Name: 'vethQ6lLx8' | Ip: '' | Eth: '6a-c2-18-f6-10-95' ###
   ### Interface 22 >> Descr: 'veth8gX8cw' | Name: 'veth8gX8cw' | Ip: '' | Eth: '76-16-5d-a9-0c-fb' ###
   ### Interface 26 >> Descr: 'vethOSG0De' | Name: 'vethOSG0De' | Ip: '' | Eth: '5e-95-9b-b7-b4-e8' ###

and parse that to extract the interface numbers (6, 10, 14..) and write an 
appropriate mrtg config file ...

Or am I missing something obvious?

Does anyone else bother with the stats of the individual containers?

Gordon