Admin Linux ... MySQL DBA

MySQL allows a client session to acquire a table lock explicitly for preventing other sessions from accessing the table during a specific period. A client session can acquire or release table locks only for itself. It cannot acquire or release table locks for other sessions. Below are the method to check lock details: SHOW ENGINE INNODB STATUS         This is generally very good, but it can get truncated, and simply may not contain every bit of info you need. Enable InnoDB Lock Monitor (enable the InnODb Lock Monitor by simply creating any innodb table named innodb_lock_monitor)         This logs a lot of extra lock information in the SHOW ENGINE INNODB STATUS output, but it can get truncated too.   Run "mysqladmin debug"         Logs all lock info to the error log. Great because it logs all locks (i.e., none truncated) and it logs LOCK TABLE locks, which do not appear in SHOW INNODB STATUS even if on an InnoDB table, because LOCK TABLE is external to the Inno

IOPS (input/output operations per second) is the standard unit of measurement for the maximum number of reads and writes to non-contiguous storage locations of devices like hard disk drives (HDD), solid state drives (SSD), and storage area networks (SAN). IOPs is often measured with an open source network testing tool called an Iometer. Some commonly accepted averages for random IO operations, calculated as 1/(seek + latency) = IOPS:  IOPS calculations Every disk in your storage system has a maximum theoretical IOPS value that is based on a formula. Disk performance — and IOPS — is based on three key factors: Rotational speed (aka spindle speed). Measured in revolutions per minute (RPM), most disks you'll consider for enterprise storage rotate at speeds of 7,200, 10,000 or 15,000 RPM with the latter two being the most common. A higher rotational speed is associated with a higher performing disk. This value is not used directly in calculations, but it is highly i