Re: Oracle 7.2 Performance Problems on Sun E450 (4 way) - SEM/S in only clue!

Question:
Did you check the archiving business. Sometimes LGWR is switching log files so frequently, the ARCH process can't cope with it anymore. As soon as ALL online redo log files need archiving, the entire database will hang. Go in to svrmgrl, issue an archive log list. Usually, if the next log the be archived is the most recent log, that is a symptom of problems.

Hth,

Sybrand Bakker

Michael George III wrote:

> Well I'm pulling my hair out.....
>
> I just finished an upgrade from Oracle V6 running on SCO (shudder) and moved
> it to Oracle V7.2 running on Solaris 2.5.1 on a 4 processor E450. Things
> were going great, queries were executing with lighting speed, the SAR
> statistics for the system were a thing of beauty and then it happened....
>
> Oracle starting freezing for periods of 5 to 45 minutes. There are no error
> messages in any of Oracle's listeners, orasrv, or alert logs. The only
> clue I have is "sar -m" which shows semapores per second (sem/s) pratically
> off the scale. Running "sar -m" usually shows sem/s around 20-40 and when
> Oracle freezes the sem/s jumps to 1000-4000.
>
> This instance is having some kind of resource contention problem, but I am
> unsure what to look for. My best guesses are it has to
>
> 1) Do with a conflict / problem using Sql*Net V1 and Sql*Net V2 listeners.
> 2) It is some sort of latch contention problem. I am tempted to crank the
> SPIN_COUNT parameter from 2000 to 4000 and see when happens.
>
> If you have any ideas, thoughts, suggestions I would welcome them. Please
> don't tell me to upgrade to Oracle 7.3, believe me I want to, but I have to
> remove the Sql*Net V1 dependency first. All in good time.
>
> Thanks!
> -Michael George III
> mgeorge3_at_wnol.net
Received on Sun Sep 06 1998 - 01:53:40 CDT