I think that this article is full of mistakes that are done by purpose (i dont know, maybe!!) or are due to the misunderstanding of those guys about many computing ideas and principles. I really think that such articles that claim to be informative should not be allowed to be on internet as it is simply saying wrong things.
My big concern about their tests is that they are not fair and they never tend yo be fair to the apple side and osx. For example i believe that everyone who pretend to make precise testing should realize that if they got results that differ so much and are so unexplained, well the best thing is to try different testing methods and tools. So tools may work well for a given platform, others may not work well. So any tempt to highlight any os design flaw should be done after testing many different benchmarking tools. They don't do that, instead they try to find some reasons that are completely meaningless in the sense that they are saying things that are technically wrong. Trying to find such whatever threading problems in osx in order to hurt the platform is not really fair......
So to begin with, let me comment on the Apache results. Well they use Apachebench to test osx, and they get rather low request per second with osx. Well ok, but why don't they try something else to test Apache performance, in that case they could figure out that the problem is either the os or the benchmarking tool (they recognize themself that apple did tell them that thre is a bug in ApacheServer, while running it on osx, maybe? i did not test it).
Try to run WebBench on osx and linux ppc or x86, and have a look to the results. Well WebBench is a largely accepted benchmarking tool for test Apache performance, so it make sense to use it too. pcmag.com have tested a Xserve G5,
http://www.pcmag.com/article2/0,1895,1630329,00.as p,
and their result show something like almost 8000 request per second for 60 clients for a static configuration test.
Ohhhh!!!! What's going on here? What we have here is something completely different, a completely different image compared to their results. What does this tell us? Well two different bench tools can produce very different outputs. But moreover everything that follows in their article simply collapse because nothing tell us that the tools that they use for MySQL testing are not having a problem too. Moreover WebBench involve as weel many threads creation, so their theory about this threading problem of osx collpase too.
We simply dont get any global image of osx performance in server applications with their limited set of bench tools. Did they never think that the problem of those results could come from the benchmarking tools or the app itself that may have performance problems while running on osx.
Here is the comment of pcmag.com
"Performance-wise, the dual-processor Xserve G5 compares well with Linux-based x86 servers. This is not surprising, considering that Mac OS 10.x is based on FreeBSD UNIX. Using the included Apache server, we ran the Xserve G5 through our standard WebBench tests. It did quite well on the static WebBench test, outperforming a competitor's dual processor x86-64 server running Apache server on SuSe Linux-64."
Something rather different to their general statement, isn't it?
So now about MySQL. So first they mention fsync(). Let me correct. What are they talking about is wrong?, fsync() behaves the same as it does on all unixes: it writes the data from the host to the drive. However this is not good enough because drives will buffer the data and potentially write it in a different order than the app did.
To deal with this, MacOS X provides an fcntl() called F_FULLFSYNC which does what fsync does and in addition asks the drive to flush all buffered data to disk. This is the only way for an app to be able to make any guarantees about things like transactions which is why InnoDB in MySQL uses it! And i think that because its an os feature it works whenever you use MyISAM o
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I think that this article is full of mistakes that are done by purpose (i dont know, maybe!!) or are due to the misunderstanding of those guys about many computing ideas and principles. I really think that such articles that claim to be informative should not be allowed to be on internet as it is simply saying wrong things. My big concern about their tests is that they are not fair and they never tend yo be fair to the apple side and osx. For example i believe that everyone who pretend to make precise testing should realize that if they got results that differ so much and are so unexplained, well the best thing is to try different testing methods and tools. So tools may work well for a given platform, others may not work well. So any tempt to highlight any os design flaw should be done after testing many different benchmarking tools. They don't do that, instead they try to find some reasons that are completely meaningless in the sense that they are saying things that are technically wrong. Trying to find such whatever threading problems in osx in order to hurt the platform is not really fair...... So to begin with, let me comment on the Apache results. Well they use Apachebench to test osx, and they get rather low request per second with osx. Well ok, but why don't they try something else to test Apache performance, in that case they could figure out that the problem is either the os or the benchmarking tool (they recognize themself that apple did tell them that thre is a bug in ApacheServer, while running it on osx, maybe? i did not test it). Try to run WebBench on osx and linux ppc or x86, and have a look to the results. Well WebBench is a largely accepted benchmarking tool for test Apache performance, so it make sense to use it too. pcmag.com have tested a Xserve G5, http://www.pcmag.com/article2/0,1895,1630329,00.as p, and their result show something like almost 8000 request per second for 60 clients for a static configuration test. Ohhhh!!!! What's going on here? What we have here is something completely different, a completely different image compared to their results. What does this tell us? Well two different bench tools can produce very different outputs. But moreover everything that follows in their article simply collapse because nothing tell us that the tools that they use for MySQL testing are not having a problem too. Moreover WebBench involve as weel many threads creation, so their theory about this threading problem of osx collpase too. We simply dont get any global image of osx performance in server applications with their limited set of bench tools. Did they never think that the problem of those results could come from the benchmarking tools or the app itself that may have performance problems while running on osx. Here is the comment of pcmag.com "Performance-wise, the dual-processor Xserve G5 compares well with Linux-based x86 servers. This is not surprising, considering that Mac OS 10.x is based on FreeBSD UNIX. Using the included Apache server, we ran the Xserve G5 through our standard WebBench tests. It did quite well on the static WebBench test, outperforming a competitor's dual processor x86-64 server running Apache server on SuSe Linux-64." Something rather different to their general statement, isn't it? So now about MySQL. So first they mention fsync(). Let me correct. What are they talking about is wrong?, fsync() behaves the same as it does on all unixes: it writes the data from the host to the drive. However this is not good enough because drives will buffer the data and potentially write it in a different order than the app did. To deal with this, MacOS X provides an fcntl() called F_FULLFSYNC which does what fsync does and in addition asks the drive to flush all buffered data to disk. This is the only way for an app to be able to make any guarantees about things like transactions which is why InnoDB in MySQL uses it! And i think that because its an os feature it works whenever you use MyISAM o