Re: Net8 Lookup Method Options - tnsnames(Local) vs. Hostname vs. Onames/LDAP

You are right in that I think Hostname is the way to go for most databases even in a large corporation. It is just too simple (1 line in listener.ora) to implement a test to not try it out. For a test I recommend using the machine name for the global_dbname, but for production usage, you should use a TCP/IP alias to the machine and code this in the listener.ora .

I see you favor Onames. I don't think Onames is that bad, but it's eventual replacement (LDAP) seems problematic at best.

Well, our large coporation appears to have some people saying we should go to LDAP with a bunch of OID databases globally just to support this crap.

We already have a not too bad tnsnames.ora "file replication" that is not that bad (hard to believe right).

Anyway, see more comments below....

-- 
"Sybrand Bakker" <gooiditweg_at_sybrandb.nospam.demon.nl> wrote in message
news:t8qhsv0h0ecbtrd62utir37gdiuqhq9es4_at_4ax.com...


> On Sat, 29 Nov 2003 12:33:49 -0600, "Burt Peltier"

> <burttemp1ReMoVeThIs_at_bellsouth.net> wrote:

>

> >"Sybrand Bakker" <gooiditweg_at_sybrandb.nospam.demon.nl> wrote in message

> >news:umvgsvourqne30skm5la8bmf13unj9kjum_at_4ax.com...

> >> Comments embedded

> >>

> >> On Sat, 29 Nov 2003 00:28:55 -0600, "Burt Peltier"

> >> <burttemp1ReMoVeThIs_at_bellsouth.net> wrote:

> >>

> >> >Just looking for some opinions (or please correct me if I am wrong) on

> >this

> >> >subject...

> >> >

> >> >Just my 1 opinion, but it seems most shops could just use the Hostname

> >> >Method for most databases and then have a 2nd fallback method

(multiple


> >> >methods easily configured in sqlnet.ora in 1 line) of the simpler

> >> >Local(tnsnames) Method.

> >> >

> >> >The other option of Onames/LDAP seems like overkill for something as

> >simple

> >> >as looking up a database, especially in an Intranet network (most

> >shops?).

> >> >

> >>

> >> IIRC, as soon as you have multiple instances on one server, you can't

> >> use the hostname method. Hence I assume most shops can't use the

> >> hostname method at all.

> >

> >Not true.

> >

> >I can see posting comments on Onames which you seem knowledge-able about,

> >but you obviously know almost nothing about Hostname.

> >

> >We have as many as 5 production instances (for the last 3 years I might

add)


> >on 1 machine using Hostname by using a separate TCP/IP alias. The alias

that


> >the GLOBAL_DBNAME points to in the listener.ora for each individual

database


> >is the one that works for it.

>

>

> Yeah sure, but you can't use failover nor standby database if you are

> using the global_dbname syntax. Apparently you don't have standby

> databases and you don't have to use failover


Ok... so what percentage of Oracle customers use failover or standby
databases?  I know in our large corporation, I think I have heard of 1
location with failover in place. That's 1 out of hundreds.



>

>

> >

> >>

> >> >1) The Local Method which uses a tnsnames.ora file has problems, but

is a


> >> >well known method. It of course has the biggest disadvantage of

> >replication

> >> >at the file system level. Of course, depending on the size of the

> >company,

> >> >the replication could be simple or very complex and problematic.

> >>

> >> Usually no tnsnames.ora will be identical, because people want to have

> >> their 'own' databases only. Also name resolution using tnsnames.ora is

> >> definitely much slower than using onames. Basically, in many

> >> orgnisations tnsnames will be a PITA

> >>

> >>

> >

> >I agree that tnsnames.ora can become a "mess" (multiple copies),  if

clients


> >can change where Oracle picks up the tnsnames.ora from (and there are

> >several ways to change this). That is why we consider it a fallback to

> >Hostname. Also, in our new organization, client's W2K ("locked") desktops

> >prevent them from easily changing this, although we have a process where

a


> >client could easily add 1 entry to the top of the tnsnames.ora file.

Being


> >at the top it will never override production entries below it in the

> >official tnsnames.ora (which is not edit-able by clients).

> >

> >It seems the only people that want (or should be allowed) to have their

> >'own' databases are mainly developers/DBAs or support staff. This seems

> >required to do their job and they should be able to fix their own

"multiple


> >copies mess". In our new organization, these people are "unlocked" and

can


> >do anything on the desktop.

> >

> >> >

> >> >2) The Hostname Method is by far the simplest to implement and

maintain.


> >>

> >> Not true.

> >

> >Statement #2 is of course true.

>

>

> Statement #2 is of course not true. There are too many limitations of


What does a limitation have to do with simplicity?



> using the hostname method. Apparently you have already decided the

> hostname method is *always* better despite the limitations being


I specifically said where I know Hostname is not going to work. So, what are
you talking about?



> mentioned. So I don't see why you bring this into discussion if you

> see using the hostname method basically as your 'gospel'


See comments at beginning...



>

> >

> >So, you are saying adding 1 line to the listener.ora and creating 1

TCP/IP


> >alias is not simple? Absolutely ZERO client *.ora files are required ...

is


> >not simple?

> >

> >>

> >> It

> >> >simply uses the existing DNS IP lookup method. It has the big

advantage


> >of

> >> >ZERO client configuration and ZERO extra infrastructure (no Onames or

> >LDAP

> >> >server required and no file system replication required). It also

appears


> >to

> >> >be quicker in every case (even when Hosntame is the LAST method to

check


> >in

> >> >the sqlnet.ora config file specification - ok just 30 or 40

milliseconds,


> >> >but still quicker).

> >> >

> >> >Of course it has the big disadvantage of requiring use of all defaults

> >for

> >> >things like port number and use of a TCP network. There are a couple

of


> >> >other limitations like you cannot use MTS or "failover - some NT/W2K

> >option

> >> >I think - not sure".

> >>

> >> Failover has NOTHING to do at all with a specific platform. You are

> >> confusing failsafe and failover.

> >> I wouldn't call not being capable to use MTS a 'limitation'. That is

> >> just a blatant understatement.

> >

> >Ok. As I said "not sure" . You are probably correct ... I am confusing

those


> >two... failsafe and failover.

> >

> >I don't think I am understating anything ... I specifically listed all

the


> >limitations ( I could think of and even 1 I was unsure of) and to catch

> >everything else ... I said anything that is not a default in tnsnames.ora

> >will not be possible with Hostname method.

> >

> >So, what exactly is the understatement?

> >

> >> >

> >> >But, aren't most people NOT using these non-default Net8 options and

> >> >therefore Hostname Method would work for most databases? With a simple

> >and

> >> >well understood fall-back  method like Local(Tnsnames), would this be

a


> >> >problem (used for some emergency or in case a non-default option

becomes


> >> >necessary)?

> >> >

> >> >3) Onames (which will be replaced by LDAP storage) seems to have the

> >> >disadvantage of requiring the most extra infrastructure. I say "seems"

> >> >because I sorta remember someone saying it works best with an OID

(Oracle


> >> >Internet Directory) LDAP storage . And, I am guessing not that many

shops


> >> >have OID implemented for LDAP.

> >> >

> >> >Onames seemed cleaner and less problematic because at least it could

be


> >> >stored in an existing database (as opposed to OID which I think should

be


> >> >installed in a database dedicated to OID). Also, Onames could cache

the


> >> >information in a local file if the Onames storage database was down,

> >which

> >> >again seems to make it also better than the LDAP replacement.

> >> >

> >>

> >> Onames *ALWAYS* caches the information, so Onames doesn't need to

> >> access the database to resolve a request. The cache file is

> >> synchronised at regular configurable intervals, and you can have

> >> delegated administration in various regions. Also, you don't need to

> >> maintain database links anymore.

> >>

> >> >

> >> >

> >> Seems like you don't have any working experience with Onames, and your

> >> background is a small company. If you have a larger organizations

> >> Onames and/or LDAP is the way to go.

> >>

> >

> >Wrong. I work for a large corporation.

>

> If you work for a large corporation I fail to see why you don't set up

> Oracle names.

>


Going away...



>  I have worked with Onames on a 2nd

> >job and it has been 5 years. So, I forgot the detail about always

cache'ing


> >to a local file.

> >

> >I should "refresh" my Onames knowledge - oh wait. That's true, Oracle

says


> >it is going away. So, why learn it?

>

> So you don't know anything about RBO because Oracle has deprecated it

> 10 years ago? Come on!

>


Well, I don't see RBO and Onames as quite the same animal... for one thing
Onames requires extra infrastructure and RBO does not.

I know there were rumors that RBO would be de-supported ... one day.  And
yes it took about 10 years for Oracle to officially announce that with10g.
And, of course, I continue to use RBO and CBO in many cases.

But, it seems like more than just a rumor and "official enough" for me that
Onames is not something anyone should migrate to. See Metalink URL
http://metalink.oracle.com/metalink/plsql/ml2_documents.showDocument?p_database_id=NOT&p_id=135696.1

It says right off the start that Oracle9i is the terminal release of Onames.
Even if it turns out this is not accurate/true, would you really recommend a
company that does not currently use Onames should migrate to Onames? I see
more than 1 place in Metalink where Oracle recommends going to LDAP.

And, again the implementation of LDAP for storing tnsnames.ora information
seems problematic to me.




> >

> >As for LDAP... someone knowledge-able can please correct me on this if I

am


> >wrong , but doesn't LDAP work better with OID (Oracle Internet

Directory)?


> >

> >Also, isn't the only other LDAP choice M$ 's implementation ?

> >

> >I feel sorry for Onames clients ...

> >

> >>

> >> --

> >> Sybrand Bakker, Senior Oracle DBA

> >

>

> --

> Sybrand Bakker, Senior Oracle DBA