Re: How can I troubleshoot without informations ?

"Jim Kennedy" <kennedy-family_at_attbi.com> wrote in message news:<ggER7.36507$ER5.447647_at_rwcrnsc52>...
> Just because the box has 2 gigs of ram doesn't mean that all that RAM is
> available to Oracle. Also I don't think that unless you have the enterprise
> version of NT (or whatever it is called) you can actually use all that RAM
> for 1 program.

I've got statistics from that server nad about 1.5 gigs of memory are free. Oracle Server has aquired just 500 megs of memory. They've told me one gig, so I need to clear this confusion. As I've heard (maybe it's wrong) standard NT server can give up to 2 gigs of memory to user processes (not Oracle, just memory for non-system threads in NTs). So I think that we should have a plenty of room to spare.

> In these "fuzzy situations", that is situations where you don't control what
> is going on you have to be skeptical about what people are telling you. I
> have found that people (especially technical people vs non-computer people )
> have a tendency to "filter out" what you are telling them. They will assume
> things and so forth because they don't believe that the problem lies in such
> and such a place. (It may not, but you need to test it to make sure it does
> not.)

Exactly my problem.

> So I really would try what I suggest. Why? It is simple. It is
> non-destructive (shouldn't hurt anything). If what I suggest does not
> change anything you learn something from the fact that you tried it. If it
> does work then you have learned something.

They've told me that they try it (decrease of DB_BLOCK_BUFFERS) and got serious perfomance downgrade.

> Basically, I am skeptical that you are not running out of memory. I think
> you are or that you have reached a limit on the number of threads per
> process - there is one for NT.(each dedicated server process on NT is
> actually a thread not a separate program) It is not unusual for each
> dedicated server process to use 1 meg of ram not including sort area size so
> 800 connections would mean 800 megs + 500 for everything else means 1.3
> gigs. Which is a lot of RAM.

Consumed space per user process depends heavily on application. This is a typical OLTP environment and it seems that user requests are not so demanding.

> So I think you have two possibilities
> 1. Running out of RAM
> 2. Running out of number of threads per process allowed under NT.
> 3. Some combination of 1 and 2.

Running out of RAM is not very probable (but I will do more inquiries), because NT administrator looks like capable guy and I think that he would know if his box runs out of memory. He has statistics for all the day in almost minutes intervals. He tries to solve this problem maybe more than Oracle DBA. Number of threads is something that come to my mind. However that should be a hard limit to number of users. Is strange that they can increase that number with decreasing of SGA, that can not has impact on number of threads.

> You need to test these theories and see if they are true or false. (don't
> guess or assume, actually test them) In either event (if they are true or
> false ) you will have learned some valuable information.

The interesting point is that this is not my box, so I don't have to take a care. Maybe DBA of that server will be happier if I do not care, but I'm very curious about all problems connected with Oracle, so I want to find out what happenned. :-) Our DBAs solved this problem very efficiently, they've handed it to Oracle support. :-(

P.S.: I've got fresh information that we have Enerprise Edition of NTs. However its configuration still prohibites to use more than 2 gigs, because NT admin thinks (I think he is true) that there is no need to change, because box has only 2 gigs of physical RAM.

--
_________________________________________

Dusan Bolek, Ing.
Oracle team leader

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