memory usage

[rvaede]

I have a server Redhat 4 and running Oracle 11 thats slow and
consumming a lot of memory and its constant.
Server has 16 GB of RAM.
I am a linux administrator so I am not familiar with the Oracle config
files.
I also noticed that the cached is consumming about 9 GB.
Would you have any advise on how to tackle this.

top - 08:48:27 up 33 days, 22:45, 1 user, load average: 0.22, 0.31,
0.43
Tasks: 109 total, 1 running, 108 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.2%us, 0.2%sy, 1.9%ni, 97.7%id, 0.0%wa, 0.0%hi,
0.1%si, 0.0%st
Mem: 16435720k total, 15975740k used, 459980k free, 171268k
buffers
Swap: 8193140k total, 116k used, 8193024k free, 9881732k
cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
COMMAND
12893 oracle 18 0 2804m 984m 5448 S 4.7 6.1 171:21.72
java
32023 oracle 18 0 3594m 1.5g 5504 S 3.0 9.7
100:39.68 java
1181 oracle 18 0 755m 301m 12m S 0.3 1.9
4:31.23 java
1557 root 10 -5 0 0 0 S
0.3 0.0 3:26.96 kjournald
11364 oracle 15 0 1569m 175m 3820 S 0.3 1.1
32:50.70 java
32579 oracle 21 0 3358m 1.2g 5264 S 0.3 7.9
57:14.52 java

[rvaede]

[mhoys]

And... what is the problem? I don't see anything wrong?

Matthias

[rvaede]

Response is slow.
The server has 16GB of RAM and its using over 15.5 GB of RAM. Cache
is high.

[joel garry]

top is misleading about how much memory oracle uses, as it doesn't
account properly for shared memory, you can see that with ipcs. If
you have access to MOS (oracle support), there are docs that explain
how to figure out how much memory oracle uses on unix. There are also
web pages floating about explaining how to mine proc, as well as
hugepages issues.

But even without all that, an admin ought to understand linux is going
to use up all the memory it can, whether for file access buffers or to
keep executables around because they might be used again or whatever.

Slow database performance is not fixed by magic parameters, it is
fixed by finding out what the holdup is and fixing that. Entire books
have been written on the subject, including in the official doc set.

You can start by looking at dbconsole, though that is by no means a
magic gui.

Welcome to the group, and see http://dbaoracle.net/readme-cdos.htm#subj12

jg
--
@home.com is bogus.
http://news.techworld.com/sme/3341396/oracle-says-cloud-computing-threatens-role-of-cios/

[Gerard H. Pille]

rvaede wrote:
> I have a server Redhat 4 and running Oracle 11 thats slow and
> consumming a lot of memory and its constant.
> Server has 16 GB of RAM.
> I am a linux administrator so I am not familiar with the Oracle config
> files.
> I also noticed that the cached is consumming about 9 GB.
> Would you have any advise on how to tackle this.
>

As was said before, using all your memory is no problem. Using more than wat you have may be, if
the system starts swapping. Check pi an po columns in vmstat (or would that be si/so?).

But you say the system is slow, response is slow. Response to which question?

[rvaede]

This is what the vmstat is displaying: the bi and so are 0. What
about the cache is over 10GB.
Its oracle OHS using Apache, the portal thats being displayed is
webcenter. Its very low.


[root@t300face01 Scripts]# vmstat 1 20
procs -----------memory---------- ---swap-- -----io---- --system--
-----cpu------
r b swpd free buff cache si so bi bo in cs us
sy id wa st
0 0 116 242956 212556 10038968 0 0 117 24 3 2
8 1 91 0 0
0 0 116 242956 212556 10038984 0 0 0 0 1008 5283
3 0 97 0 0
0 0 116 242956 212556 10038984 0 0 0 12 1006 4998
0 1 99 0 0
1 0 116 242956 212560 10038980 0 0 0 64 1011 5042
6 0 94 0 0
0 0 116 242956 212560 10038984 0 0 0 0 1013 4985
11 0 89 0 0
0 0 116 242956 212560 10038984 0 0 0 0 1004 5192
0 0 100 0 0
0 0 116 242956 212560 10038984 0 0 0 0 1003 4872
4 0 96 0 0
0 0 116 242956 212560 10038984 0 0 0 0 1022 5054
0 0 99 0 0
2 0 116 242956 212568 10038980 0 0 0 40 1005 5247
6 0 94 0 0
0 0 116 242956 212568 10038980 0 0 0 0 1012 5086
11 1 88 0 0
0 0 116 242956 212568 10038988 0 0 0 0 1007 5346
0 0 100 0 0
0 0 116 242956 212568 10038988 0 0 0 0 1018 5269
4 0 96 0 0
0 0 116 242956 212568 10038988 0 0 0 4 1008 5301
0 0 99 0 0
2 0 116 242956 212572 10038984 0 0 0 16 1010 5198
7 0 94 0 0
0 0 116 242956 212572 10038988 0 0 0 0 1009 4986
10 0 90 0 0
1 0 116 242956 212572 10038988 0 0 0 0 1009 5170
0 0 100 0 0

There is a portal

[Gerard H. Pille]

rvaede wrote:
> On Mar 1, 1:13 pm, "Gerard H. Pille"<g...@skynet.be> wrote:
>> rvaede wrote:
>>> I have a server Redhat 4 and running Oracle 11 thats slow and
>>> consumming a lot of memory and its constant.
>>> Server has 16 GB of RAM.
>>> I am a linux administrator so I am not familiar with the Oracle config
>>> files.
>>> I also noticed that the cached is consumming about 9 GB.
>>> Would you have any advise on how to tackle this.
>>
>> As was said before, using all your memory is no problem. Using more than wat you have may be, if
>> the system starts swapping. Check pi an po columns in vmstat (or would that be si/so?).
>>
>> But you say the system is slow, response is slow. Response to which question?
>
> This is what the vmstat is displaying: the bi and so are 0. What
> about the cache is over 10GB.
> Its oracle OHS using Apache, the portal thats being displayed is
> webcenter. Its very low.
>
>

How low can you go?

This machine is asleep, no wait and a 100% idle. A web server being slow can be a network
problem, otherwise I'd start looking elsewhere. Oracle Portal uses a database. On which
machine is that one running?

[Mladen Gogala]

You should make sure that out of memory killer is active and kills
everything allocating more than 128K or memory. Your memory problems will
become history.



--
http://mgogala.byethost5.com

[Mladen Gogala]

On Thu, 01 Mar 2012 09:07:00 -0800, rvaede wrote:


> Response is slow.
> The server has 16GB of RAM and its using over 15.5 GB of RAM. Cache is
> high.

What does it mean "cache is high"? What kind of cache? Page cache? DB
cache? IO cache? ACME cache? What is kept in the cache that is high? IO
buffers? VM pages? DB buffers? Weapons of mass destruction? Once you
answer the question what is kept in the cache that "is high", you will
stand a good chance of fixing the perceived problem. On the other hand, I
am not sure that the "cache is high" is an accurate description of your
problem. This question sounds about the same as the one that some novice
users usually ask me, tricked by the more experienced colleagues: "why is
the database slow today?". Database is a place, it cannot be slow. The
question makes approximately the same amount of sense as the question why
is the Statue of Liberty slow today. So, let's go back to the "cache is
high" phrase. A possible solution is for the cache to stop smoking pot.
If the cache being "high" contains pages, we are talking about page
cache. There is a way to reduce page tables on Linux: huge pages. There
is an ample documentation on MOS, no need to delve into the nitty gritty
details.
If the cache being high is the IO cache (system buffers) then don't use
the buffered I/O. Direct I/O will usually decrease the cache use
instantly. Direct IO, also fairly well documented on MOS. For a brief
explanation, you can also take a look here:

http://mgogala.byethost5.com/Linux_VM.pdf

This paper is rather old and it would be about time to update it and make
a new revision which would mention huge pages, iotop, perf, out of memory
killer some additional parameters and the brand new features in kernel
3.0, like de-duplication: http://lwn.net/Articles/386090/
http://www.linuxplanet.com/linuxplanet/reports/6919/2


A lot has happened since that article was written, but the basic advice
is still sound: turn on the direct I/O, utilize huge pages, and configure
your OS memory properly. Unfortunately, I am undergoing a very tumultuous
period of my life and chances that this paper will be revised before the
end of this year are very slim. Of course, finding someone to fund the
new revision would also help and increase chances exponentially. I need
my cash to be high, too.

--
http://mgogala.byethost5.com

[Gerard H. Pille]

On 2 mrt, 06:10, Mladen Gogala <gogala.mla...@gmail.com> wrote:

...


There seems to be some noise on the line. Don't be put off by
Mladen, Roger, and let's concentrate on the problem at hand.

[John Hurley]

rv:

# I have a server Redhat 4 and running Oracle 11 thats slow and

consumming a lot of memory and its constant.

... Server has 16 GB of RAM. I am a linux administrator so I am not

familiar with the Oracle config files.

Have you tried contacting the responsible DBA and/or DBA team? That
is the only real sensible starting point to me.

[Mladen Gogala]

On Thu, 01 Mar 2012 23:59:15 -0800, Gerard H. Pille wrote:

> There seems to be some noise on the line. Don't be put off by Mladen,
> Roger, and let's concentrate on the problem at hand.

What is the fracking problem at hand? I love the new technology, it comes
up with the useful words like "fracking". I had to use "fork" before, but
"fracking" is definitely better.



--
http://mgogala.byethost5.com

[TheBoss]

Mladen Gogala <gogala...@gmail.com> wrote in
news:pan.2012.03...@gmail.com:
<...>

> exponentially. I need my cash to be high, too.
>

This definitely is a sign of less-than-optimal Costs.
Time to re-read Jonathan's books? ;-)

--
Jeroen