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Oracle Enterprise Manager for MySQL Database User's Guide  /  Metrics  /  InnoDB Semaphore Activity Metrics

6.16 InnoDB Semaphore Activity Metrics

Lists the InnoDB Semaphore Activity metrics and provides a brief description of each.

Table 6.16 InnoDB Semaphore Activity Metrics

NameDescription
Mutex Os Waits (Delta)The number of InnoDB semaphore/mutex waits yielded to the OS.
Mutex Rounds (Delta)The number of InnoDB semaphore/mutex spin rounds for the internal sync array.
Mutex Spin Waits (Delta)The number of InnoDB semaphore/mutex spin waits for the internal sync array.
Os Reservation Count (Delta)The number of times an InnoDB semaphore/mutex wait was added to the internal sync array.
Os Signal Count (Delta)The number of times an InnoDB thread was signaled using the internal sync array.
Rw Excl Os Waits (Delta)The number of exclusive (write) semaphore waits yielded to the OS by InnoDB.
Rw Excl Rounds (Delta)The number of exclusive (write) semaphore spin rounds within the InnoDB sync array.
Rw Excl Spins (Delta)The number of exclusive (write) semaphore spin waits within the InnoDB sync array.
Rw Shared Os Waits (Delta)The number of shared (read) semaphore waits yielded to the OS by InnoDB.
Rw Shared Rounds (Delta)The number of shared (read) semaphore spin rounds within the InnoDB sync array.
Rw Shared Spins (Delta)The number of shared (read) semaphore spin waits within the InnoDB sync array.
Spins Per Wait Mutex (Delta)The ratio of InnoDB semaphore/mutex spin rounds to mutex spin waits for the internal sync array.
Spins Per Wait Rw Excl (Delta)The ratio of InnoDB exclusive (write) semaphore/mutex spin rounds to spin waits within the internal sync array.
Spins Per Wait Rw Shared (Delta)The ratio of InnoDB shared (read) semaphore/mutex spin rounds to spin waits within the internal sync array.