On Mon, 25 Jan 2010, zhengfeng wrote: > Hi~,all > > For test the performance of syslogd in RHEL5.4GA, I had written one small > program by calling the interfaces syslog()... > > But the results is not very steady. > Please look the results below: > > The 1st time, some days ago, I test 10 times, every time sending logs to > syslogd 30 secs, after then reboot. > > Results: > 1,110 1,101 1,103 1,092 1,088 1,101 1,098 1,096 1,087 1,087 > 2.12% > > > > But Today , I use the same codes and method to test , the results are: > > 1,295 1,292 1,297 1,291 1,288 1,287 1,284 1,279 1,275 1,270 > 2.13% > > > (1290-1100)/1100 > 10% > > Why the resluts upwards are so different? What induced? And how can i avoid > that?
there are a lot of things that could be causing this. However you didn't give us enough information to figure it out. what else is running on the system? what are the specs of the system? (is it a single core single processor, or do you have multiple processors) what filesystem are you using? when you say that you write logs for 30 seconds and reboot, are you allowing rsyslog to flush out pending writes, or are you loosing all logs that haven't been written yet (this will also involve what version of rsyslog are you testing and how do you have it configured) how much cpu is rsyslog using during the time that it is running the test? (total time, and if you have multiple cpu cores on the system, the peak cpu of individual threads) how large is the queue that rsyslog is allowed to use? if the numbers you are reporting are the total logs written, they seem very low. on a current rsyslog with reasonable hardware I would expect the numbers to be tens of thousands of log messages per second, it may be that the bottleneck is the process writing to syslog() rather than rsyslog itself. 30 seconds is a very short time for a test, depending on your filesystem it may not have written anything out to the disk by the time you finish the test. David Lang _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com
