Re: Trying to wrap my head around TAF

From: Charles Schultz <sacrophyte_at_gmail.com>
Date: Fri, 19 Jun 2009 15:03:41 -0500
Message-ID: <7b8774110906191303l5679bc24x1db6abc9dd9f08a4_at_mail.gmail.com>



For #2, I do see table
95-3<http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/d_serv.htm#sthref5797>, but I missed how it specified "server-side TAF". How does a *server*transparently failover?

On Fri, Jun 19, 2009 at 14:56, Charles Schultz <sacrophyte_at_gmail.com> wrote:

> [Warning: High acronym content]
>
> So I have been reading the online documentation and giving myself a
> headache. =) Interesting how easy it is to get distracted and start reading
> about FCF, ONS, FAN and the like. I have two points that I think are
> specific to TAF and would appreciate clarification from those that have used
> these things in Real Life(tm).
> 1) The MAA documentation sets constantly refers to using both RAC and DG
> for HA.Yet only in a very few places do I see TAF configurations utilizing
> both RAC and DG. For example, here is snippet from "Client Failover Best
> Practices for Highly Available Oracle Databases: Oracle Database 10g Release
> 2<http://www.oracle.com/technology/deploy/availability/pdf/MAA_WP_10gR2_ClientFailoverBestPractices.pdf>
> ":
> SALESOCI =
> (DESCRIPTION =
> (ADDRESS_LIST =
> (ADDRESS = (PROTOCOL = TCP)(HOST = BOSTON1)(PORT = 1521))
> (ADDRESS = (PROTOCOL = TCP)(HOST = BOSTON2)(PORT = 1521))
> (ADDRESS = (PROTOCOL = TCP)(HOST = CHICAGO1)(PORT = 1521))
> (ADDRESS = (PROTOCOL = TCP)(HOST = CHICAGO2)(PORT = 1521))
> (LOAD_BALANCE = yes)
> )
> (CONNECT_DATA=
> (SERVICE_NAME=salesOCI)
> )
> )
>
> Additionally, in other bodies of work I very rarely see this combination. I
> am curious, if this is a "Best Practice", how come it is not more widely
> used? Surely this is not that new (while the whitepaper cited above is from
> March of 2009, the features are from Oracle 10gR2). Are folks using this
> type of connection string in Real Life, to not only go between nodes in one
> cluster, but also to "failover" to standby nodes? Note that in the quoted
> example, this is *not* a stretch cluster (between Chicago and Boston!
> Wow!), but rather a Primary/Standby environment.
>
> 2) Similar to this, I am trying to understand the different TAF parameters
> used in dbms_service.create_service<http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_serv.htm#i1001480>.
> The documentation has very little to say about them (just the bare bones -
> the 11g documentation<http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28419/d_serv.htm#sthref7056>is exactly the same I think), and when one implicitly creates a service by
> modifying the SERVICE_NAMES parameter, all the parameters default to null
> (according to dba_services). Are those TAF parameters actually used, or are
> they merely place-holders for "future" functionality? If they do play a role
> in TAF, what and how?
>
> Thanks for your time and help.
>
> --
> Charles Schultz
>

-- 
Charles Schultz

--
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Received on Fri Jun 19 2009 - 15:03:41 CDT

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