Subject Re: High Mutex Wait Figures
Author Greg Kay
We have buffers set to 200. Normally the mutex wait value is low and
after restarting the lock manager it has returned to normal.

--- In, "Ann W. Harrison"
<aharrison@...> wrote:
> Greg Kay wrote:
> > Does anyone have any ideas on what might be causing high mutex wait
> > figures?
> The mutex wait is amount of time processes spend waiting their turn
> to update the lock table. In classic, though we talk about the lock
> manager as if it were a separate process, the code is actually in
> each process. In the early dark ages there were implementations that
> had a separate lock manager process, but they're long gone. When a
> process wants to request or release a lock, it puts itself on a queue
> for the mutex that guards the table. When it gets that mutex, it
> its changes - sending signals as necessary - and releases the mutex.
> The goal is for the changes to be really really fast.
> From the lock prints you sent, it looks as if each change is taking
> longer than it should.
> How many buffers are you using per connection?
> Regards,
> Ann