Jmeter: Understanding the relationship between bandwidth and KB / sec.
I have a thread group of 15 threads, each sending a 32KB image (HTTP POST). In the summary report, I have 550 / sec throughput, average response time: 25ms, and KB / sec is 148KB / sec. I find it difficult to match these numbers. if I can manage 550 req / sec and each req is 32KB, shouldn't the KB / sec be 550 * 32KB / sec?
EDIT: Even when I only send one request, the number under KB / Sec just doesn't make sense. I can match all the other numbers. Summary report for 1 request:
Samples: 1
Average: 25
Min: 25
Max: 25
Std.Dev: 0
Error: 0%
Throughput: 40/sec
KB/Sec: 10.62
Avg. Bytes: 272.
It's pretty easy to compare the average time and throughput from the above result. The size of the transmitted image is 32281 bytes (as reported by the Linux operating system). As noted in the comments, I doubt this should do anything with compression. I tried to send a 1MB image, KB / Sec reported 12.3.
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The math in the example for 1 query looks correct to me.
Samples: 1
Average: 25
Min: 25
Max: 25
Std.Dev: 0
Error: 0%
Throughput: 40/sec
KB/Sec: 10.62
Avg. Bytes: 272.
According to your data above 40 requests per second, on average 272 bytes = (40 * 272) 10880 bytes per second (which is 10.625 when divided by 1024).
The question is why exactly JMeter thinks the average request size is 272 bytes and you think it is 32k - are you sure the image is attached? if so, I would guess that there is some pretty heavy compression going on.
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