Hi Tony,
My english must be pretty bad but the documentation is right. You cannot
have 2 backends with the same name in the cluster (on the same or on
different controllers).
Transfer MOVES one backend from controller x to controller y. So after
the transfer command successfully completes, the backend does not exist
anymore on controller x but is active on controller y (and the backend
name remains the same).
Clone is another command with a completely different purpose which is to
create dynamically new backends in the cluster that were not declared in
your virtual database configuration file.
In short, if you use the same configuration file on your 2 controllers,
the backend names will conflict.
Emmanuel
Sorry, when I said 'clone' in the e.g. from my last email, I meant
'transfer'.
So the way your email reads, a backend can have the same name on a
different controller. The naming only has to be unique to the
controller. So if I took my VD config from controller1 and copied it to
controller2 exactly, I'd have no naming conflict.
If so, then this section 5.3.5 (page 27) of the 2.10 install guide is
ambiguous:
"Each <DatabaseBackend/> definition in a virtual database configuration
must be
unique. In other words, two database backends must not have the same
name even if
they belong to a different controller."
-Tony
---------------------------
Manager, IT Operations
Format Dynamics, Inc.
303-573-1800x27
[EMAIL PROTECTED]
http://www.formatdynamics.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Emmanuel Cecchet
Sent: Thursday, April 17, 2008 10:15 AM
To: Sequoia general mailing list
Subject: Re: [Sequoia] clone config, naming question
Tony,
You are confused with 2 different commands:
- transfer: migrates one backend from one controller to another
controller (keeps the same name)
- clone: creates a copy of the configuration of an existing backend
(with a new name) on the same controller
Clone should not allow you to create a new backend with the same name as
an existing backend (unless there is a bug!).
Hope this helps,
Emmanuel
I'm sorry, this still eludes me. If it keeps the same name across
multiple controllers, wouldn't that violate the naming rules, since
the
clone is now making the name not-unique?
e.g.
Start with:
CONTROLLER1: backend1
CONTROLLER2: Nothing
Clone backend1 to controller2, now have:
CONTROLLER1: backend1
CONTROLLER2: backend1
Violates rule
-Tony
---------------------------
Manager, IT Operations
Format Dynamics, Inc.
303-573-1800x27
[EMAIL PROTECTED]
http://www.formatdynamics.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Emmanuel Cecchet
Sent: Wednesday, April 16, 2008 6:11 PM
To: Sequoia general mailing list
Subject: Re: [Sequoia] clone config, naming question
It keeps the same name, that's why it must be unique.
Emmanuel
Anthony J. Biacco wrote:
For the unique naming..what happens if I used the "transfer backend"
command to transfer a backend from one controller to another? How
would
it get named in the other controller?
-Tony
---------------------------
Manager, IT Operations
Format Dynamics, Inc.
303-573-1800x27
[EMAIL PROTECTED]
http://www.formatdynamics.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Emmanuel Cecchet
Sent: Wednesday, April 16, 2008 4:40 PM
To: Sequoia general mailing list
Subject: Re: [Sequoia] clone config, naming question
Tony,
1. Am I correct in assuming that if I use the "clone" command in the
console to duplicate a backend config to a new backend, that that
config is active only in memory? So if I restarted the controller,
the
new backend would then be missing, if I didn't go in the virtual
databases config xml file and put the new backend config in there?
Yes, this is correct but you can also save a controller configuration
through the console (just make sure you reload that config when you
restart the controller).
2. Am I correct in assuming from the docs that every backend must
have
a unique name? e.g. in a 2-controller 2-backend setup, backend #1
must
have a different name in controller #2 than controller #1, e.g.
db-01-01 in controller #1 and db-01-02 in controller #2, even though
they're the same backend?
Yes, as backends can be transferred from one controller to another,
it
is necessary to be able to identify them globally.
Best regards,
Emmanuel
--
Emmanuel Cecchet - Research scientist
EPFL - LABOS/DSLAB - IN.N 317
Phone: +41-21-693-7558
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