Re: redo per second (size)on exadata ?

  • From: Seth Miller <sethmiller.sm@xxxxxxxxx>
  • To: agonenil@xxxxxxxxx
  • Date: Tue, 2 Sep 2014 16:15:48 -0500

Amihay,

Just to clarify and as Riyaj has already mentioned, you are talking about
"megabytes per second" and not "megabits per second", correct? There is a
very big difference (a factor of 8).

If you are talking about megabytes, it would be written as 80MB, not 80Mb.

Seth Miller




On Tue, Sep 2, 2014 at 3:47 PM, amihay gonen <agonenil@xxxxxxxxx> wrote:

> Hi David,
> thanks for your answer and for other answers and suggestions . it is
> really help and this what make this forum an excellent forum.
>
> I'll try to provide more input. Yes , we are talking on 80Mb per second of
> redo ,actually I've able to squeeze even then 100mb of redo per second per
> node from our exadata (quarter machine ).
>
> The reason for it is that  we are currently checking the limits of our
> product (http://www.axxana.com/   , sorry for the PR :-)  ).   Our
> product integrate into exadata (or any another oracle  ) and provide
> no-data loss protection .
>
> my question that was raised before is what will the redo per second
> generating of high-end oracle (OLTP) setup , or in other words what should
> be scale the  our product (software+hardware) should support.
>
> Thanks,
> Amihay
>
> p.s. If anyone want more input on our solution , feel free to send me
> message in private
>
>
>
>
>
> On Tue, Sep 2, 2014 at 8:50 PM, David Fitzjarrell <
> dmarc-noreply@xxxxxxxxxxxxx> wrote:
>
>> If she really means 80 mb per second on the redo generation that would
>> generated a large number of log switches; presuming you are using the
>> recommended redo log size of 4gb we're talking one log switch every 50
>> seconds.  You're not restricted to 4 gb logs so if this is anticipated to
>> be the  'normal'  traffic on your OLTP system you might want to consider
>> even larger logs.  My guess on this is the 80 mb per second isn't the redo
>> rate, it's the transaction rate and that could mean less actual redo volume
>> generated.  You really need to clarify what this 80 mb per second rate
>> really means.
>>
>> David Fitzjarrell
>>
>> Principal author, "Oracle Exadata Survival Guide"
>>
>>
>>   On Thursday, August 28, 2014 10:06 AM, "Powell, Mark" <
>> mark.powell2@xxxxxx> wrote:
>>
>>
>>   I imagine that the redo rate varies greatly between systems.  How you
>> looked to see what your past rate or redo generation happens to be?  You
>> ought to be able to use that as a comparison number or baseline.  My main
>> system appears to only generate between 30G – 40G of redo per day across
>> both nodes.  I have several other systems that generate far less.
>>
>>
>> *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
>> oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *amihay gonen
>> *Sent:* Thursday, August 28, 2014 6:55 AM
>> *To:* ORACLE-L
>> *Subject:* redo per second (size)on exadata ?
>>
>>  Hi all,
>>  I've been asked by our VP to give estimation what is consider heavy
>> system OLTP  in term of redo per bytes rate.
>>
>>  She told to to test our exadata machine with load of 80Mb per second
>> per Node , and I've told her that I think it is too much .
>>
>>  if OLTP system with generate 80Mb* (2 nodes) per second that it means
>> 576G per hour .
>>
>>
>>  I wonder if anyone work with such systems , what is the typical redo
>> rate ?
>>
>>
>>  thanks
>>  amihay
>>
>>
>>
>>
>>
>>
>

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