>>>>> "Timothy" == Timothy Chi <tchi@stripped> writes:
Timothy> Hi Sinisia,
>> Please check a size of your partition where database files are.
Timothy> 17 Gig, about 9% used
>> Second, do you use any table locks ??
Timothy> No, we don't use any table locks.
Timothy> Interestingly enough, we've been on the phone with Sun and they gave us a
Timothy> few commands to run to track the processor utilization. The mpstat command
Timothy> gave us an abnormally high value for the "smtx" column (which basically
Timothy> represents cross-processor locking). Sun said that this number, at its
Timothy> highest should be around 200, and our system is reporting values up towards
Timothy> 13,000. Sun said that most of the threads are user threads causing this, so
Timothy> that this is an application related issue.
Timothy> Here's the snip from Sun Tech Support:
>> The data you sent appears to verify that there is a lock contention
>> issue caused by MySQL itself. This article describes how to
>> interpret the
>> data, and how to collect more data about the application itself:
>> http://www.sunworld.com/swol-08-1998/swol-08-perf.html I'll leave
>> this open until you've looked at that, and checked the resources for
>> MySQL.
<cut>
One suggestion:
In sql/mysqld.cc you can find the following code:
#ifdef HAVE_THR_SETCONCURRENCY
(void) thr_setconcurrency(20); // We are iobound
#endif
Try increasing/decreasing the '20' value. Does this help ?
(If yes, I will add this as a standard MySQL variable)
Regards,
Monty
