ULC semaphore requests

“ULC Semaphore Requests” reports the number of times a user task was immediately granted a semaphore or had to wait for it. “% of total” shows the percentage of tasks granted semaphores and the percentage of tasks that waited for semaphores as a percentage of the total number of ULC semaphore requests. This is relevant only in SMP environments.

A semaphore is a simple internal locking mechanism that prevents a second task from accessing the data structure currently in use. Adaptive Server uses semaphores to protect the user log caches since more than one process can access the records of a ULC and force a flush.

This category provides the following information: