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Home -> Community -> Mailing Lists -> Oracle-L -> RE: RAC or Oracle Fail Safe
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Answers in line...
That's not totally true, For a DBA it shouldn't matter much, whether he is setting up RAC or OFS. But yes relatively RAC is a bit complex to manage.
Not true really, user's session will flash error message and he will have to re login. This is true in both the cases(unless you implement TAF "Transparent Application Failover" logics in your application for RAC". One major difference would be that in RAC user can re-login immediately, while in OFS he has to wait till the other node bring the database up.
Yes other node can be configured to take over automatically base on some simple in-built logic. But a DB recovery might be required depending on specific cases.
Yes you are right here.
HTH,
Rajesh
-----Original Message-----
From: ml-errors_at_fatcity.com [mailto:ml-errors_at_fatcity.com] On Behalf Of
Hussain Ahmed Qadri
Sent: Thursday, July 17, 2003 11:04 AM To: Multiple recipients of list ORACLE-L Subject: RE: RAC or Oracle Fail Safe
Thank you to all those who replied and who intend to reply to this one :)
We are using Dell PE4600 servers. My concern was that I read it somewhere
that if one of the node goes down, then the clients have to restart the
application to log in again to the database, is that true? And is it any
different on RAC?
We have the licensed RAC and Oracle Fail Safe CDs, so that is not an issue.
I also believe that setting up RAC is more complex, so we wanted to confirm
that if Fail Safe gives us HA, 24x7, and any change in node shifting (when
active is down, passive becomes active) is transparent to the user then we
should go for Fail safe.
By the way, we intend to keep cluster settings of ACTIVE and PASSIVE, is
there any issue regarding this?
Tanel Poder: you said that, " in event of failure you can start up instance on another node that will mount, recover and open the database." Doesn't the second node automatically take over? And this means that the user has to log in again, do I get it right?
Best Regards,
Hussain
-----Original Message-----
Sent: Wednesday, July 16, 2003 10:44 PM
To: Multiple recipients of list ORACLE-L
Hi!
RAC - One database, two (or more) instances servicing it concurrently. If one node crashes, second one starts recovering, your uncommitted transactions and session state variables (package variables) on failed instance are lost.
FailSafe - One database, one instance servicing it at any time, in event of failure you can start up instance on another node that will mount, recover and open the database.
With RAC you can have some kind of transparent failover which is able to reexecute your queries on survived instance, but AFAIK for uncommitted transaction survivability your app has to be coded to support it. Also, with RAC you may scale your system up to support more users in some cases.
RAC is additional $20k per CPU, FailSafe comes with EE, I believe.
Tanel.
> Hello all,
>
> We have setup a Microsoft Cluster Server (MSCS) cluster, with two nodes,
using W2K, and now are in the process of deploying Oracle 9i on it. For the
purpose of high availability (HA), we are deliberating on setting up either
RAC or Oracle Fail Safe. The confusion is over the fact that if we get HA
with oracle Fail Safe, i.e. if one node is down due to any problem, then the
other takes over, then can we do without RAC?
> Which of these two is more transparent to the user, i.e. which will take
less time to shift the load from one node (server) to the other node?
> Can any one explain the benefits of using RAC over Oracle Fail Safe, or
vice versa.
>
>
>
>
>> To REMOVE yourself from this mailing list, send an E-Mail message
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> ---------------------------------------------------------------------
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: tanel.poder.003_at_mail.ee 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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hussain Ahmed Qadri INET: hussain_at_skm.org.pk 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). ------=_NextPart_000_01D9_01C34C54.3BB61B60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; = charset=3DWindows-1252"> <META NAME=3D"Generator" CONTENT=3D"MS Exchange Server version = 6.0.6249.1"> <TITLE>RE: RAC or Oracle Fail Safe</TITLE> </HEAD> <BODY> <!-- Converted from text/plain format --> <P><FONT SIZE=3D2>Answers in line...<BR> <BR> -- I also believe that setting up RAC is more complex,<BR> <BR> That's not totally true, For a DBA it shouldn't matter much, whether he = is setting up RAC or OFS. But yes relatively RAC is a bit complex to = manage.<BR> <BR> -- and any change in node shifting (when active is down, passive = becomes active) is transparent to the user<BR> <BR> Not true really, user's session will flash error message and he will = have to re login. This is true in both the cases(unless you implement = TAF "Transparent Application Failover" logics in your = application for RAC". One major difference would be that in RAC = user can re-login immediately, while in OFS he has to wait till the = other node bring the database up.<BR> <BR> -- Doesn't the second node automatically take over?<BR> <BR> Yes other node can be configured to take over automatically base on some = simple in-built logic. But a DB recovery might be required depending on = specific cases.<BR> <BR> -- And this means that the user has to log in again, do I get it = right?<BR> <BR> Yes you are right here.<BR> <BR> HTH,<BR> Rajesh<BR> <BR> -----Original Message-----<BR> From: ml-errors_at_fatcity.com [<A = HREF=3D"mailto:ml-errors_at_fatcity.com">mailto:ml-errors_at_fatcity.com</A>]&n= bsp; On Behalf Of Hussain Ahmed Qadri<BR> Sent: Thursday, July 17, 2003 11:04 AM<BR> To: Multiple recipients of list ORACLE-L<BR> Subject: RE: RAC or Oracle = Fail Safe<BR> <BR> Thank you to all those who replied and who intend to reply to this one = :)<BR> <BR> We are using Dell PE4600 servers. My concern was that I read it = somewhere that if one of the node goes down, then the clients have to = restart the application to log in again to the database, is that true? = And is it any different on RAC?<BR> We have the licensed RAC and Oracle Fail Safe CDs, so that is not an = issue. I also believe that setting up RAC is more complex, so we wanted = to confirm that if Fail Safe gives us HA, 24x7, and any change in node = shifting (when active is down, passive becomes active) is = transparent to the user then we should go for Fail safe.<BR> By the way, we intend to keep cluster settings of ACTIVE and PASSIVE, is = there any issue regarding this?<BR> <BR> Tanel Poder: you said that, " in event of failure you can start up = instance on another node that will mount, recover and open the = database."<BR> Doesn't the second node automatically take over? And this means that the = user has to log in again, do I get it right?<BR> <BR> <BR> Best Regards,<BR> <BR> Hussain<BR> <BR> -----Original Message-----<BR> Sent: Wednesday, July 16, 2003 10:44 PM<BR> To: Multiple recipients of list ORACLE-L<BR> <BR> Hi!<BR> <BR> RAC - One database, two (or more) instances servicing it concurrently. = If<BR> one node crashes, second one starts recovering, your uncommitted<BR> transactions and session state variables (package variables) on = failed<BR> instance are lost.<BR> <BR> FailSafe - One database, one instance servicing it at any time, in event = of<BR> failure you can start up instance on another node that will mount, = recover<BR> and open the database.<BR> <BR> With RAC you can have some kind of transparent failover which is able = to<BR> reexecute your queries on survived instance, but AFAIK for = uncommitted<BR> transaction survivability your app has to be coded to support it. Also, = with<BR> RAC you may scale your system up to support more users in some = cases.<BR> <BR> RAC is additional $20k per CPU, FailSafe comes with EE, I believe.<BR> <BR> Tanel.<BR> <BR> ----- Original Message -----<BR> To: "Multiple recipients of list ORACLE-L" = <ORACLE-L_at_fatcity.com><BR> Sent: Wednesday, July 16, 2003 7:44 PM<BR> <BR> <BR> > Hello all,<BR> ><BR> > We have setup a Microsoft Cluster Server (MSCS) cluster, with two = nodes,<BR> using W2K, and now are in the process of deploying Oracle 9i on it. For = the<BR> purpose of high availability (HA), we are deliberating on setting up = either<BR> RAC or Oracle Fail Safe. The confusion is over the fact that if we get = HA<BR> with oracle Fail Safe, i.e. if one node is down due to any problem, then = the<BR> other takes over, then can we do without RAC?<BR> > Which of these two is more transparent to the user, i.e. which will = take<BR> less time to shift the load from one node (server) to the other = node?<BR> > Can any one explain the benefits of using RAC over Oracle Fail = Safe, or<BR> vice versa.<BR> ><BR> > Regards,<BR> ><BR> > Hussain<BR> ><BR> > DBA SKMCH&RC<BR> ><BR> > --<BR> > Please see the official ORACLE-L FAQ: <A = HREF=3D"http://www.orafaq.net">http://www.orafaq.net</A><BR> > --<BR> > Author: Hussain Ahmed Qadri<BR> > INET: hussain_at_skm.org.pk<BR> ><BR> > Fat City Network Services -- 858-538-5051 <A = HREF=3D"http://www.fatcity.com">http://www.fatcity.com</A><BR> > San Diego, California -- = Mailing list and web hosting services<BR> > = ---------------------------------------------------------------------<BR>= > To REMOVE yourself from this mailing list, send an E-Mail = message<BR> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and = in<BR> > the message BODY, include a line containing: UNSUB ORACLE-L<BR> > (or the name of mailing list you want to be removed from). = You may<BR> > also send the HELP command for other information (like = subscribing).<BR> ><BR> <BR> <BR> --<BR> Please see the official ORACLE-L FAQ: <A = HREF=3D"http://www.orafaq.net">http://www.orafaq.net</A><BR> --<BR> Author: Tanel Poder<BR> INET: tanel.poder.003_at_mail.ee<BR> <BR> Fat City Network Services -- 858-538-5051 <A = HREF=3D"http://www.fatcity.com">http://www.fatcity.com</A><BR> San Diego, California -- = Mailing list and web hosting services<BR> ---------------------------------------------------------------------<BR>= To REMOVE yourself from this mailing list, send an E-Mail message<BR> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in<BR> the message BODY, include a line containing: UNSUB ORACLE-L<BR> (or the name of mailing list you want to be removed from). You = may<BR> also send the HELP command for other information (like subscribing).<BR> --<BR> Please see the official ORACLE-L FAQ: <A = HREF=3D"http://www.orafaq.net">http://www.orafaq.net</A><BR> --<BR> Author: Hussain Ahmed Qadri<BR> INET: hussain_at_skm.org.pk<BR> <BR> Fat City Network Services -- 858-538-5051 <A = HREF=3D"http://www.fatcity.com">http://www.fatcity.com</A><BR> San Diego, California -- = Mailing list and web hosting services<BR> ---------------------------------------------------------------------<BR>= To REMOVE yourself from this mailing list, send an E-Mail message<BR>Received on Thu Jul 17 2003 - 02:11:54 CDT
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