Oracle 9i ADR on HPUX Serviceguard

[Delrish]

I think , you should use oracle dataguard in Maximum Protection mode.This mode offers the highest level of data protection. Data is synchronously transmitted to the standby database from the primary database and transactions are not committed on the primary database unless the redo data is available on at least one standby database configured in this mode. If the last standby database configured in this mode becomes unavailable, processing stops on the primary database. This mode ensures no-data-loss.

[Delrish]

HP has solutions for Disaster recovery too. However HPâ s solution is more expensive than Oracle DataGuard and required special hardware and software. For data protection you can use HP StorageWorks Continuous Access. Take a look at following link:
http://h18006.www1.hp.com/products/storage/software/conaccesseva/index.html

And for datacenter protection you can use HP Metrocluster support for HP StorageWorks Continuous Access EVA or HP Continental clusters.These solutions have some limitations.Take a look at following links for this issue:
http://h71028.www7.hp.com/enterprise/cache/108988-0-0-0-121.html
http://h71028.www7.hp.com/enterprise/cache/4182-0-0-0-121.html

Also you can use HP Serviceguard Extension for RAC for this purpose too.
http://h71028.www7.hp.com/enterprise/cache/257273-0-0-0-121.aspx
I believe the Oracle Data Guard is a better and cheaper solution for data protection and disaster recovery.

Alireza

[Yogeeraj_1]

hi,

Oracle Replication would be the solution.

With Oracle 10g, you have STREAMS coming in with powerful routines for replication.

please read about them


kind regards
yogeeraj

[Yogeeraj_1]

hi,

I think this will be possible with Oracle's Advanced Replication Option that gives you the ability to automatically propagate data to any Oracle database and most other databases via Oracle Gateways.

Data is guaranteed to be consistent because of two phase commit. Data can move in either or both directions thanks to a wide variety of conflict resolution schemes.


Disconnected machines like laptops as well as network, hardware, or software outages do not affect Oracle Replication. As soon as the affected link is restored, Oracle Replication automatically continues.

USES: --Off loading data to a data warehouse
--Backup database for disasters
--Dissemination of data to remote databases
--Collection of data from remote databases


also read the metalink paper:
Migrating Advanced Replication Environment to Streams Replication Environment

hope this helps too!

kind regards
yogeeraj

[Shivkumar]

Sirs,
We already have RAC and ADR implemented on HPUX MC/Serviceguard. My concern was that replication doesn't happen intantaneously, it takes 1 or more minutes, i guess.

[Steven E. Protter]

Shalom Shiv,

How fast the data replication occurs depends on the bandwith, the power of the computers involved and some factors merely beyond your control like distance and weather.

There is no fool proof solution, nothing that does it instantaneously.

Oracle dataguard is in essense log replicaiton, followed by applying of those logs.

If the transaction volume is not to heavy and the connection not disrupted, you can be assured that replication will occur fairly quickly, measured in seconds or even fractions of a second.

SEP

[Shivkumar]

Hi Indira, What is your take on this ?

Regards,
Shiv

[Indira Aramandla]

Hi Shivkumar,

I am sorry for the delayed reply. I did not get to see your post during the Christmas break. Today I saw your update.

I do not have much experience with this. In my openion (similar to others) would be
one of the configuration that Oracle provides Advanced replication environments that support an update-anywhere data model. To help administer advanced replication environments, Oracle provides the Replication Management section in Enterprise Manager.

As Yogeeraj mentioned, Oracle Streams introduced since Oracle 9.2 is the other option. This enables the sharing of data and events in a data stream, either within a database or from one database to another.
Oracle 9.2 has introduced a more flexible and efficient way of implementing replication using Streams. In the contrary to what it happens on Advanced Replication, there is no a Master Definition Site and all the sites plays the same role.
Every database involved in the Streams replication is in charge of capturing those changes involved in the replication and propagating them to the other sites. Also every database is in charge of applying those entries coming from other sites.

Then in a bidireccional database we will have 2 Streams, one from site A to site B and the other from Site B to Site A.

I am not sure if this answers your query about the update of one database be propogated to the other instantly. there might be a time gap.
or may be I was thinking on the lines of writing table triggers, as soon as the tbale data is update then the trigger starts the update to the table on the other database thought the database link........some think on those line.


Indira A

[Shivkumar]

Oracle 9.2 has resolved some of our application issues.

I am suspecting the streaming technology might have helped in this.

Was streaming technology not available in earlier version of Oracle 9.2 ?

[Indira Aramandla]

Hi Shivkumar,


Oracle Streams was introduced since Oracle 9.2. So Oracle 9.2.x or higher releases will have this functionality.



Indira A