MySQL CPU usage difference between my local server and Linode server

Question

I have 2 similar servers, one on my local computer, the other on Linode. OS is Ubuntu 20.04 LTS on both.

When I import a large database into MySQL, my local computer uses less than 10% of CPU while the Linode server uses 100% of CPU. So Linode server completes the import much faster than my local computer.

What configuration makes the difference?

Which "import" mechanism are you using? What versions of MySQL? How big is the 'large' database? — Rick James, Sep 27 '21 at 02:40
@RickJames: I created a backup file using mysqldump and import it using mysql command. The large database is about 1GB. — Sam Kong, Sep 27 '21 at 04:41
I guess the problem was that the local computer uses an external HDD and the database backup file is on that. So reading the drive slows down. I need to verify my theory, though. — Sam Kong, Sep 27 '21 at 04:43

score 1 · Accepted Answer · answered Sep 27 '21 at 14:27

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SSDs are on the order of 10 times as fast as HDDs. That does not directly explain "100% cpu". Instead, if the CPU @10% too 10 times as long (elapsed time), then that matches a CPU @100%.

answered Sep 27 '21 at 14:27

Rick James

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I confirm that the problem was slow drive. So I changed mysql data dir to SSD and now CPU is almost 100%. The HDD was the bottle neck. – Sam Kong Sep 30 '21 at 19:02
@SamKong - Now we can look at the query to see if a better index or better formulation would decrease the CPU. (I find that nearly all 100%-CPU queries can be sped up.) – Rick James Sep 30 '21 at 21:20

MySQL CPU usage difference between my local server and Linode server

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