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I am reading to all tutorials/books that when running SHOW ENGINE INNODB STATUS the Per second averages calculated from the last X sec, the X should be 20 to 30 seconds. I have never manage to exceed 10 sec, so my question is: Is the output valid? i can count on these statistics? Is there something i am missing here some parameter to collect status statistics more efficient?

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The SHOW ENGINE INNODB STATUS \G command will show data from the last time the command was run till now - not sure what it will be the first time. I can't shut down the server here, but if you run the command rapidly twice in succession, you'll see the time since last run - set your

mysql> pager less;

mysql> show engine innodb status \G


=====================================
2014-07-04 15:44:42 7f0a2d9c9700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 6 seconds

Take a look here - averages of less than ~30 seconds are worthless according to Peter Zaitsev. You could also take a look at Baron Schwartz's innotop tool - available here.

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  • Thanks, but what does that mean the last time the command was run till now?
    – Antonios
    Jul 4, 2014 at 15:00
  • Sorry if I wasn't clear. If you notice in my answer, I ran the SHOW ENGINE INNODB STATUS twice - the first time was 6 seconds before the example I showed you. As you have read, you should take averages over a longer period - I was just demonstrating the time that the command uses - you control it - if you issue the command twice, once immediately after the other, it will show 1 - 2 seconds. Jul 4, 2014 at 15:06
  • So if you have never run it before, it will give you the server up-time as average?
    – Antonios
    Jul 4, 2014 at 15:09
  • That's what I said I wasn't sure of. You'll have to check that yourself, since I can't shutdown my server here. Jul 4, 2014 at 15:13
  • There is no meaningful rule of thumb. Averages for 1 second are worthless because that second could be atypical. But the same can be said for 20 seconds intervals, on many servers. Even for days can be completely atypical in some cases. Also averages without standard deviation could mean anything. Common sense is always needed. Nov 22, 2020 at 17:48

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