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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Re: Sizing - RAC, storage subsystem EMC
Hello,
For quite some time I have been wondering
whether we (the DBAs) need to 'go slow' on 'recommending'
RAC (considering the HUGE investments required
to get it up and running)
in view of the present...'scenario'..
Can we have 'some repository' of 'real experiences'
(I mean not the type of experiences Oracle Marketing
routinely totes up :( )
with RAC?
(cos I cant believe that there could exist any business
which needs to be supported using such costly stuff :(
and which does not have a cheaper/better alternative)
Can someone please suggest if it is a basic database design
flaw which leads to the requirement of such costly technologies
like RAC in the first place?
(I mean if the dataset is huge why not use transportable
tablespaces
and keep 'regularly purging' the database of 'old data'?)
(oh ok..now please dont take it personally and assume
that I am nit picking on someone/anyone who is
using/recommending RAC
....it is just that I want to explore and understand
alternatives!)
Can someone point to some 'good reasons'
(please do not cut and paste from Oracle documents!!)
where RAC
was the 'only possible solution available' ?
Also in our (the DBA) desire to work with the
'latest and largest' I hope we are not biting Oracle's bait
and suggesting solutions with our resumes more in mind ;)
than the 'poor hapless customer' :(
(having Oracle as a product is bad enough for the customer
having a dba around 'usually' is a BIG pain :)) )
Arun's comments were interesting...
sure BIGGIES like Oracle and yahoo can afford 'costly
technology'
(cos anyway they must be living on OPM ;) (other people's money)
!)
but what about mid/small sized companies...
at the rate Oracle is going with its products...
(they have put 'everything' in 9iAS and made it costly :( )
I wont be surprised if Mid/small sized companies 'shop
elsewhere'
and then surely Oracle and yahoo cant be hiring all of us ;)
All the above of course are based on my limited knowledge of
RAC and a deep skepticism of BIGGIES :(
looking for good reasons for correction ;)
and if someone from Oracle is listening ;)
I wish Oracle would change its attitude (not just logo ;) )
to
'software that powers Business' ;)
( we all know how far it 'powered the internet' ;) )
Thanks for your time
Cyril Thankappan
On Sat, 24 May 2003 Rachel Carmichael wrote :
>
>Here's the thing. Disks are cheap. Maybe. But buying 5 disks is
>still
>cheaper than buying 10 disks. And it is NOT the people who
>actually
>work with the disks (DBAs, Sysadmins, even developers) who have
>the
>authority to order the disks.
>
>You need places and floor space to put the disks as well. It's
>not like
>you can just hang them from the ceiling.
>
>And even more so these days, and it seems most especially in the
>US
>companies, companies are trying to cut costs to the bone (we just
>went
>through an exercise where we practically had to jump through
>hoops just
>to get more memory for a production system which obviously needed
>the
>memory). And cutting costs means as few disks as possible, means
>reuse,
>consolidate and do without.
>
>It kind of reminds me of one of the sayings my parents (who grew
>up
>during the Great Depression here) have told me of that time:
>"use it
>up, make it do, or do without"
>
>we're in the "do without" phase
>
>Rachel
>--- Mogens_Nørgaard <mln_at_miracleas.dk> wrote:
> > I'm beginning to think that we're having this wonderful
>discussion
> > about
> > RAID-5 time and again because the vendors keep coming up
>with
> > arguments
> > to prove that the general laws of nature don't apply to this
> > particular
> > technology.
> >
> > In the 50s we had a prime minister here in Denmark that said
>to the
> > assembled parliament: "If that's the facts, then I deny the
>facts".
> > Somehow you have to admire a guy like that.
> >
> > Since disks are now cheap, how on Earth is it that we allow
>various
> > IO-vendors to bundle cheap disks, expensive cache which we
>won't
> > need,
> > and stupid technologies like RAID-5 into a box called SAN/NAS
>or
> > whatever and charge 42 billion units of some real currency for
>it?
> >
> > Why don't we take our swords and shotguns and AK-74s (that's
>the
> > small
> > calibre), and point them at them until they actually just
>bundle a
> > bunch
> > of inexpensive disks into RAID 1+0 which we ALL know is
>superior to
> > RAID-S, RAID-5 (notice how S looks like 5 - it's no
>coincidence).
> > It's
> > superior to RAID 0+1 even. It doesn't require (the expensive)
>cache
> > either.
> >
> > One of my wonderful experiences was with a TelCo here, where
>the
> > vendor
> > kept saying that they should of course just add cache if
>performance
> > wasn't sufficient. When they finally reached the 32GB (yep,
> > thirty-two
> > giga-bytes) of cache alone, they gave up, ripped the stuff
>apart and
> > reconfigured it as RAID 0+1 and it finally performed on the
>small
> > writes. We all loved it - except possibly the disk-vendor, who
>kept
> > saying RAID-<some letter that resembles the number 5> was of
>course
> > fantastic, and that they shouldn't listen to all these bitter,
>old,
> > twisted Oracle people who just hated RAID-5 and the likes ...
>ahhh...
> >
> > just because!
> >
> > It's got nothing to do with Oracle or not. It's got to do with
>money
> > and
> > brains.
> >
> > RAID 1+0 is the best you can buy.
> > RAID 0+1 is almost as good.
> > RAID 5 sucks - in all its disguises and permutations -
>compared to
> > 0+1
> > or 1+0.
> >
> > If RAID-5 is good enough for you, fine. But remember to test
>the
> > good,
> > old restore of the backup and time it so that you're prepared
>if it
> > happens. It should of course take about four times as long as
>the
> > backup.
> >
> > As Connor said (and Cary has said it in his excellent, but
>futile,
> > RAID-5 paper) it's when you really, really need disk
>performance that
> >
> > RAID-5 will let you down.
> >
> > Yo.
> >
> > Mogens
> >
> > Arun Annamalai wrote:
> >
> > > Hi George.
> > >
> > > I would recommend go with Raid 5 and its not that one
>transaction
> > > triggers that many writes as you have
>mentioned/calculated.
> > > It is all buffered with recovery mechanism.
> > >
> > > Have you thought about Raid4(Network appliance) hardware. (I
>am no
> > way
> > > affliated with Network appliance, except that we use in our
>site.)
> > > Most of the big names use them, such as
> > > 1, Yahoo. (you can see network appliance logo when you
>logout of
> > your
> > > yahoo email account)
> > > 2. Oracle
> > > 3. Southwest airlines.
> > >
> > > I mean Yahoo, Southwest Airlnes are all heavy transaction
>oriented
> > > shop on a given per minute interval.
> > > The most common overhead of SAN is that the throughput of
>the
> > switch
> > > that connects your server to the san storage.
> > >
> > > Also, heard that Net App (best in NAS) is colloborating
>with
> > Hitachi
> > > (best in SAN storage) to get the best technology for storage
>and
> > > thoroughput performance. But this might take a while or
>might
> > already
> > > be in the market. Check out with your local Hitachi or
>Netapp
> > > representatives.
> > >
> > > Hope this helps.
> > > -Arun.
> > >
> > >
> > > ----- Original Message -----
> > > From: George.Leonard_at_za.didata.com
> > > <mailto:George.Leonard_at_za.didata.com>
> > > To: Multiple recipients of list ORACLE-L
> > > <mailto:ORACLE-L_at_fatcity.com>
> > > Sent: Tuesday, May 20, 2003 2:06 AM
> > > Subject: Sizing - RAC, storage subsystem EMC
> > >
> > > Hi all, hope you can give some input ideas.
> > >
> > >
> > >
> > > I am in the process of designing a system for a client
>of ours
> > for
> > > a proposal
> > >
> > >
> > >
> > > The sizing information I have been given is as
>follows.
> > >
> > >
> > >
> > > 58.1 million tickets/day at 351 bytes per record. The
>record
> > was
> > > complete populated (all columns filled to max) in a
>table and
> > then
> > > analyzed. Average row size 351 bytes.
> > >
> > > =~ 19 GB/day. Raw data. Plus overhead (indexes, temp
>space,
> > > rollback, some other data etc) here and there I have
>requested
> > 5 TB.
> > >
> > >
> > >
> > > We need to keep records for a month. Table design I am
>looking
> > at
> > > is a date partition with a second level hash partition.
>This is
> > so
> > > that I can move data in the oldest week/table space off
>line
> > and
> > > write them to optical storage for possible retrieval at
>a later
> > > date (requirement).
> > >
> > >
> > >
> > > Of course this will be on locally managed table spaces
>with
> > auto
> > > storage management for segments.
> > >
> > >
> > >
> > > Hardware:
> > >
> > > The database will be a Oracle RAC 9.2.0.4 on Sun cluster
>3
> > build
> > > on 2 x Sun StarFire V880, 4 CPU's, 4 GB RAM each,
> > >
> > > Connected to an EMC SAN via Fiber Channel
> > >
> > >
> > >
> > > I do not have more information about the EMC array at
>the
> > moment.
> > > Hitachi has been mentioned. (excuse the spelling)
> > >
> > >
> > >
> > > Question I have.
> > >
> > >
> > >
> > > I have been asked how many writes the Database will be
>doing to
> > > the SAN per second.
> > >
> > > I have determined that I should expect about 2000
> > tickets/second.
> > >
> > > The table in question will have 2 indexes.
> > >
> > >
> > >
> > > Now following rough guessing I said I should expect at
>least 16
> > > 000 writes/second
> > >
> > >
> > >
> > > This was done by say/assuming
> > >
> > >
> > >
> > > 2 writes for the redo log files (2 members)
> > >
> > > 2 writes for the control files (2 control files)
> > >
> > > 2 writes to index blocks
> > >
> > > 1 write to undo table space block
> > >
> >
>=== message truncated ===
>
>
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>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.net
>--
>Author: Rachel Carmichael
> INET: wisernet100_at_yahoo.com
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Cyril Thankappan INET: cyril_thank_at_rediffmail.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Sun May 25 2003 - 02:23:35 CDT
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