[asterisk-users] Scaling Asterisk: Dual-Core CPUs not yielding gains at high call volumes - Low volume benchmarks

[Matthew J. Roth]

William Moore wrote:
> Are you recording memory figures as well and have you checked the
> total used memory?  Or did I miss it somewhere?  Thanks for doing
> this, scalability testing is always good.

William,

This round of benchmarking is heavily focused on CPU utilization,
because it is causing an immediate problem for me.  However, I am
tracking some other statistics on a daily basis including memory
utilization, swap utilization, load averages, and active channels and calls.

One of my colleagues takes the text file I produce and creates graphs
using Cacti and rrdtool.  You'll be interested in these two (sorry for 
the format of the URLS, but otherwise the list was eating my posts):

- Percent CPU Used With No. Calls and No. Channels
<img509DOTimageshackDOTusSLASHimg509SLASH3927SLASHastcpuandcallsbf4DOTpng>
- Asterisk Memory Used (KB)
<img47DOTimageshackDOTusSLASHimg47SLASH7615SLASHastmemusedgq9DOTpng>

Note that even with a peak call volume of approximately 400 active calls
and 550 active SIP channels, the memory utilization never surpasses 600
KB.  I'd estimate that most Asterisk installations would avoid swapping
with 1 GB of RAM.  A 2nd GB might be useful to provide plenty of room
for file caching so that your hard disk doesn't become a bottleneck.  We
also record all of our calls to a 6 GB RAM disk, so our server has a
total of 8 GB of RAM but that isn't necessary in most circumstances.

Overall, Asterisk seems to be very efficiently coded as far as memory is
concerned.  Note that for other reasons we perform a nightly reboot, so
I don't know if there are any memory leaks that would surface over time.

Thank you,

Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer