RE: A high-availability question (standby , replication or ....)

HACMP on AIX works the same way. It is more complex like I said to setup and run. But the failover abilities are Great. But it was expensive. Lots of dual hardware that just sat there waiting for a failover.

-----Original Message-----
Sent: Thursday, August 16, 2001 5:04 PM
To: Multiple recipients of list ORACLE-L ....)

MC/Serviceguard in HP. This offers availability for the database as well as application. Standby is a good alternative. Risk with Standby is fail-over is
manual and user intervention required, also keeping the Standby in Sync is a problem. MC/Serviceguard allows you to have multiple boxes in the cluster and
all the boxes are available all the time. (like DB1 can run on node1, DB2 can
run on node2).

Fail-over is automatic as all file systems get unwonted on the box having problem and get mounted onto another box. It is extremely easy to maintain in a
shared disk (like EMC) environment. Only negative point is it takes 3-4 minutes
to move from one node to the other, so during this time environment is not available. Several of our production DBs work this way, and the DBAs/SAs don't
even have to wake up in case of fail-over. Everything is automatic.

For Non-HP environments, go with Standby.

Rama

Kevin Lange wrote:

> Rachel is 100% right (do we ever expect differently ??)
>
> We currently use standby databases that have their logs updated every 15
> minutes. If the Prod goes down it does take some manual intervention on
our
> part ... chaning DNS and brining the Standby up in real mode. But our
down
> time is less than an hour. That is acceptable in our work. It was also
> the simplest to create and maintain.
>
> As for replication, at my old job we replicated DB2 data down to Oracle
> every 5 minutes. There were times when communications lagged and the
> replications broke. This caused a lot of problems because we ended up
> having to rebuild the table way too many times. The setup was also
complex.
> It took us to maintain it and it was a 24x7 job. This one had the added
> complexity of not having structure changes automatically roll between
> databases. Whenever we changed something on the master side we had to
> physically go and make the changes on the secondary side.
>
> We also setup oracle to oracle replication. That was another nightmare.
> We had to make sure structres were maintained between these as well. High
> Maintenance, High setup.
>
> Now .... for Failover. We were in the process of getting ready to setup
> HACMP rollovers between two servers. WOW ... now THAT was complicated
AND
> EXPENSIVE.
>
> -----Original Message-----
> Sent: Thursday, August 16, 2001 12:06 PM
> To: Multiple recipients of list ORACLE-L
> ....)
>
> Standby... even if I have to be paged in the middle of the night to bring
it
>
> up and live.
>
> replication is a nightmare to implement unless you plan for it. Standby is
a
>
> breeze to implement and maintain.
>
> >From: Andrey Bronfin <andreyb_at_elrontelesoft.com>
> >Reply-To: ORACLE-L_at_fatcity.com
> >To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> >Subject: A high-availability question (standby , replication or ....)
> >Date: Thu, 16 Aug 2001 08:11:09 -0800
> >
> >Dear gurus !
> >
> >A customer wants to have a backup database on a remote "in case of
> >disaster"
> >site.
> >That database needs to be as much in sync with the primary DB as
possible,
> >and a sort of failover must be implemented ,
> >i.e. if the primary site fails , the users will be AUTOMATICALLY routed
to
> >the secondary one .
> >
> >I thought of 2 possible approaches :
> >multimaster asynchronous replication and a standby database.
> >The problem is that AFAIK , there is no automatic failover in case of
> >standby DB , i.e.. U need to issue "ALTER DATABASE ACTIVATE STANDBY
> >DATABASE; " or something like that on a backup site.
> >From the other hand multimaster replication sounds like a big headache .
> >
> >So , gurus , what would U suggest ?
> >How do U implement HA on your sites ?
> >
> >Thanks a lot in advance for your time.
> >
> >Andrey.
> >
> >
> >
> >
> >--
> >Please see the official ORACLE-L FAQ: http://www.orafaq.com
> >--
> >Author: Andrey Bronfin
> > INET: andreyb_at_elrontelesoft.com
> >
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Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Rama Malladi
  INET: rama_at_toyota.com

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-- 
Author: Kevin Lange
  INET: kgel_at_ppoone.com

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