* Ryan O'Hara <[email protected]> [Mon, 3 May 2010 09:55:30 -0500]:
On Sun, May 02, 2010 at 07:53:12PM +0400, Sergey Tumaev wrote:
> Hi,
>
> I have measured the performance of Openais messaging with the
primitive
> client/server setup:
> 1. Server - receives the message from client and sends it back:
> ...
> while(1){
> result = saMsgMessageGet (srv_queue_handle, &msg_a,
> &msg_time, &id, SA_TIME_ONE_MINUTE);
> if (result != SA_AIS_OK) {
> printf ("Could not receive message %d\n", result);
> saMsgQueueClose (srv_queue_handle);
> saMsgFinalize (handle);
> exit (1);
> }
> result = saMsgMessageReply(handle, &msg_a, &id,
> SA_TIME_ONE_SECOND);
> if (result != SA_AIS_OK) {
> printf ("Could not send message %d\n", result);
> saMsgQueueClose (srv_queue_handle);
> saMsgFinalize (handle);
> exit (1);
> }
> }
> ...
>
> 2. Client - sends/receives message to/from server:
> ...
> gettimeofday(&t0, NULL);
> while(i++<1000){
> result = saMsgMessageSendReceive(handle, &srv_queue_name,
> &msg_a, &msg_a, 0, SA_TIME_ONE_SECOND);
> if (result != SA_AIS_OK) {
> printf ("TEST-1: Could not sent message to srv_queue
> %d\n", result);
> saMsgQueueClose (clt_queue_handle);
> saMsgFinalize (handle);
> exit (1);
> }
> }
> gettimeofday(&t1, NULL);
> temps = t1.tv_sec - t0.tv_sec;
> if(temps && (t0.tv_usec > t1.tv_usec)){
> tempm = 1000000 + t1.tv_usec - t0.tv_usec;
> temps = temps - 1;
> }
> else{
> tempm = t1.tv_usec - t0.tv_usec;
> }
> printf("TEST-1: Total %d send/recieve = %dsec %dµs\n", i,
temps,
> tempm);
> ...
> Test between two host machines: is ~18sec for 1000 messages.
> Two processes on same host: is ~33sec (!) for 1000 messages.
> Each message has 32 bytes size.
>
> Both results are looking too slow for messaging.
> Inter-process testing even slowly that inter-host!
> What wrong with my test?How to improve the performance?
>
> Version:
> corosync-1.2.1
> openais-1.1.2
> System:
> Intel(R) Core(TM)2 Quad CPU Q9400 @ 2.66GHz
> Linux debian 2.6.26-2-686
We've never done any sort of performance testing with MSG service, so
I'm not sure that your performance measurements are reasonable. The
AIS specification gives no requirements for performance.
Measuring the time to complete a saMsgMessageSendReceive is going to
be the worst performance of any API call. You are 1) sending a
message, waiting for another process to read that message, send a
reply, etc. I'm assuming that your "server" has a saMsgMessageGet call
pending at all times, correct?
One thing worth mentioning is that both saMsgMessageGet and
saMsgMessageSendReceive have to create new IPC connections each time
they are called. As a result, there is a fair amout of overhead each
time one of those calls is made, especially when those calls return.
The MSG service is still very new. In fact, you are the first person
that I know has used it. The primary goal duing development to
correctly implement the specification. Performance was secondary, as
we can hopefully improve performance as the code matures. That said,
there are some known bugs in the current implementation of the MSG
service. I am working on addressing some of those bugs and a new
release will hopefully be available soon.
Ryan
Hi Ryan,
First of all I would like to thank all developers of this project.
Openais/Corosync is alive, great job!
About my testing.
I'm planning to use openais services in my project,
therefore I try to specify all possible problems.
I have specially chosen saMsgMessageSendReceive function,
because I understand that it should be slowest (blocking mode).
But that I need.
The scenario is very simple:
One process ask another process (on same or another host) to transmit
some parameter.
The process have to get this parameter in blocking mode and sets it in
own RAM.
It's very important for application that this transaction is finished as
soon as possible.
Inter process messaging is more critical for me that inter host, but it
approximately twice more slowly.
Though should be on the contrary.
Would you please explain it?
Thanks in advance,
Sergey Tumaev.
[http://foto.rambler.ru/print]
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