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user165222
Asked: 2015-10-24 10:58:29 +0800 CST

Trying to understand sysbench

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I'm trying to do some basic server benchmarking with sysbench. I understand most of the options, but I was wondering if someone could explain the --max-requests general option.

Is it applicable to all tests? What exactly does it do? For example, if I run the command:

sysbench --test=fileio --file-total-size=100G --file-test-mode=rndrw --num-threads=8 --file-extra-flags=direct --max-requests=0 run

What does max-requests do in that context? I get 0 is unlimited, but what exactly are the requests and how do they relate to threads, etc? None of the manpages or blogs explain what a "request" is. I played around with it during a cpu test and the higher the number, the more my run time increases, the lower it is the quicker my run time. Why?

Thanks!

linux

1 Answers

  1. Best Answer

    In the context of fileio benchmark, max-requests is the maximum number of allowed I/O operations. For example, specific a max-requests of 100 means that fileio can at most execute 100 I/O operation, being reads or writes.

    In the context of oltp benchmark, max-requests it the total number of allowed SQL statement (being SELECT/INSERT/UPDATE or whatever). For example, using the default 10000 requests limit means that an oltp "simple" (read only) test will issue up to 10000 requests, and then exits.

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