Hi Steven,
I have done some investigations about the heavy cpu usage of cpgbench. I think cpu is used up mainly because if cpgbench calls cpg_mcast_joined() with CS_ERR_TRY_AGAIN returned, it simply try it again. Many useless trying again will happen if the network can be easily congested. So are there any asynchronous method we can use in that senario to reduce cpu usage?
On 01/08/2013 11:26 PM, jason wrote:
Jason,Update : By using iperf to check multicast performance, iperf also give a bad result(100Mbit/sec) on my virtual machine, but CPU usage is very low(only 1%). The command I used is :
iperf -c 239.255.1.10 -u -l 8K -b 1G -w -i 5 -t 300 -T 4
Unfortunately the virtual network drivers perform very poorly with multicast. Multicast is not a operational mode the authors of those operating system drivers have optimized. You might try udpu which uses unicast (which has been optimized), although I can't guarantee performance will be great either.
Most of the development of Corosync is on bare metal and optimized for that environment.
Totem uses alot of CPU to operate, especially with encryption. The usage may be higher depending on how many cpu cores you have and which version you are using. 1.4.x uses threads, which cause some context switching chaos - so more cores here would be helpful. I'd recommend giving 2.x a try if you haven't.
Regards
-steve
On Jan 9, 2013 1:57 PM, "jason" <huzhijiang@xxxxxxxxx> wrote:
Hi Jan,
Between our two virtual machines, iperf -i 1 -w 1M can reach line rate that is 1.00 Gbit/sec. But I do not know why cpgbench only got 10 MB/s. And when cpgbench was running, top showed it used up almost one CPU. 30% in usermode, 70% for in kernel mode.
On Dec 10, 2012 3:28 PM, "Jan Friesse" <jfriesse@xxxxxxxxxx> wrote:
Jason,
jason napsal(a):
> Hi All,
> Currently we created a 16 nodes(virtuallization) cluser environment to test
cool
> the performance of the Totem protocol. We wan to see the relationship
> between the cluster size(the amount of nodes ) and the bandwidth/latency.
After you will finish testing, can you please share results?
> And I found there are already some test utilities that I can use such as
> cpgbench, evtbench and pload and I want to know which tool is the best
> that I should use to meet my requirement and is there any other way to test
Question is, what type of performance you would like to test. Is that
bandwidth, or latency? Network or local one? cpgbench seems to be
generally best for testing both bandwidth (with big messages) and
latency (with small messages). I would not recommend pload, because this
makes corosync to behave weird (it's almost removed in 2.x).
Honza
> such performance?
>
>
>
>
> _______________________________________________
> discuss mailing list
> discuss@xxxxxxxxxxxx
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