Re: How to troubleshoot heavy RAM consumption
- From: Neil Kodner <nkodner@xxxxxxxxx>
- To: Jared Still <jkstill@xxxxxxxxx>, oracle-l-freelists <oracle-l@xxxxxxxxxxxxx>, Neil Kodner <nkodner@xxxxxxxxx>
- Date: Tue, 23 Mar 2010 11:59:27 -0400
I'd say we're spending plenty of time swapping
oracle- WSCP10>vmstat 5 12
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr m0 m1 m3 m4 in sy cs us sy
id
0 2 0 23249264 8514968 1870 1499 16473 55 56 94048 21 0 0 0 0 5234 23399
15356 10 6 84
0 7 0 9463488 654320 580 4993 3588 3 3 55544 0 0 0 0 0 5454 77866 22089 38
10 52
0 7 0 9447904 638992 303 4079 7302 2 2 32816 0 0 0 0 0 5536 128397 21793 41
12 47
0 8 0 9451584 642008 1124 5260 7920 2 2 19384 0 0 0 0 0 5824 123475 23344
34 15 51
0 12 0 9449792 636648 1950 5793 21752 5 3 10312 0 0 0 0 0 6481 95698 24062
41 16 43
0 7 0 9442400 627152 2319 6994 21926 3 2 6104 0 0 0 0 0 5850 148490 23835
33 17 49
0 7 0 9400144 577904 1945 6007 25373 0 0 95704 0 0 0 0 0 5065 98153 20889
34 13 53
0 12 0 9448896 622712 2941 4145 33929 0 0 56520 0 0 0 0 0 4877 70036 21715
32 11 57
0 17 0 9804352 956424 3381 7072 39866 5 5 33392 0 0 0 0 0 5987 111988 24021
31 18 51
0 20 0 9730568 884992 3132 9930 32109 2 2 19728 0 0 0 0 0 7168 142250 25074
45 18 37
0 17 0 9773440 924344 1662 6122 20420 42 42 11664 0 0 0 0 0 6672 125605
30617 40 16 44
0 12 0 9770808 918480 1036 6440 11618 3 3 6904 0 0 0 0 0 7420 134967 28124
49 18 33
On Wed, Mar 10, 2010 at 8:38 PM, Jared Still <jkstill@xxxxxxxxx> wrote:
> Heavy use of swap can be a good indication of memory shortage.
>
> You can't simply rely on the '29G swap' reported however.
>
> True, that is a lot of swap, but what you probably want to track
> is how much time the system is spending on swapping memory.
>
> vmstat 5 12 will show a minutes worth at 5 second intervals.
>
> It's been quite awhile since I worked on Solaris, but I do know
> there are some other things to look for there.
>
> When looking for Solaris advice, it wouldn't hurt to include
> Glenn Fawcett in your search terms. :)
>
> http://blogs.sun.com/glennf/
>
>
> Re the advice views, I've found them to be pretty good the
> few times I have used them.
>
>
> Jared Still
> Certifiable Oracle DBA and Part Time Perl Evangelist
> Oracle Blog: http://jkstill.blogspot.com
> Home Page: http://jaredstill.com
>
>
>
> On Wed, Mar 10, 2010 at 4:11 PM, Neil Kodner <nkodner@xxxxxxxxx> wrote:
>
>> Thanks for all of your help. I dont know if this is a case of 'need more
>> memory' or need more tuning and have never really been in this situation
>> before. This used to be plenty of server 5-6 years ago but now, as
>> unemployment has not only increased, but benefit eligibility has increased,
>> we are doing far more business than ever.
>>
>>
>> On Wed, Mar 10, 2010 at 4:57 PM, Jared Still <jkstill@xxxxxxxxx> wrote:
>>
>>>
>>> On Wed, Mar 10, 2010 at 2:09 PM, Neil Kodner <nkodner@xxxxxxxxx> wrote:
>>>
>>>> Thanks. As an aside, while we're having memory/paging issues, is there
>>>> a good way to tell if our SGA is in fact too large? One of the challenges
>>>> that we face is that one of the heavier-used applications does not use
>>>> prepared statements and that has the potential to pollute the shared pool.
>>>> We enable cursor-sharing at the session level for these users.
>>>>
>>>>
>>> In general I would think the SGA too large if there were more
>>> free memory available at peak periods than need be.
>>>
>>> select *
>>> from v$sgastat
>>> where name = 'free memory'
>>> order by upper(name)
>>> /
>>>
>>> The 'need be' is the hard part. I personally don't have to go
>>> through this kind of exercise very often.
>>>
>>> If I had allocated 12 gig for an SGA and consistently had 2 gig
>>> free I would certainly consider distributing some of that elsewhere.
>>>
>>> Jared Still
>>> Certifiable Oracle DBA and Part Time Perl Evangelist
>>> Oracle Blog: http://jkstill.blogspot.com
>>> Home Page: http://jaredstill.com
>>>
>>>
>>>
>>
>
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