I am facing slowness issue on MySQL Slave. I am suspecting this due to OS I/O as i compared Spin rounds per wait values with PROD. Slave have higher values. Also slave has less resources compared to PROD.


OS WAIT ARRAY INFO: reservation count 572783, signal count 1796058 Mutex spin waits 15479300, rounds 12039758, OS waits 109005 RW-shared spins 618729, rounds 8406119, OS waits 254889 RW-excl spins 242434, rounds 7770788, OS waits 205984 Spin rounds per wait: 0.78 mutex, 13.59 RW-shared, 32.05 RW-excl

  • The values you pasted are mostly counters so by themselves are not relevant only with tracking their changes by time. Does it help you if get the definition of spin rounds? Or are you looking for more details on solving the performance problem? ps.: in an ideal situation slaves should have very different read characteristics than the master therefore these values should always be different. – Károly Nagy Jun 27 '16 at 9:27
  • Definition can help for troubleshooting my issue. – AnonDude Jun 27 '16 at 12:51
  • Usually I find that performance problems can be adequately tackled from the SQL and/or index end of the spectrum. Start a second thread for tackling your performance issue that way. – Rick James Jul 8 '16 at 4:23

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