Messages in this thread |  | | Date | Wed, 7 Feb 2007 10:49:53 -0500 | From | "Sen Horak" <> | Subject | Performance of concurrent senders |
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Hi --
I have been running some experiments involving processes sending large volumes of data concurrently. The results show (on Linux 2.6.19.2) that although the total throughput achieved by all the processes remains constant, the jitter increases as the number of processes increases. Beyond about 64 processes (on a 2.4GHz Xeon with 4Mb of cache), processes start getting starved and the streams get very bursty.
Are there any steps one can take to make the jitter scale better, eg. by using another scheduler? I guess that it is reasonable that the jitter grow with added contention through the TCP/IP stack - but what growth rate is acceptable? Is the data I have below reasonable?
The jitter varies as follows and is shown as an average+/- sd across 25 10-second intervals.
Concurrency Jitter (us)
1 1.6+/-0.8 2 1.5+/-1.1 4 1.4+/-0.6 8 0.8+/-0.5 12 2.3+/-1.2 16 3.3+/-2.1 20 4.6+/-2.5 24 6.2+/-1.4 28 7.8+/-3.2 32 10.0+/-3.4 64 100+
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