Let me make sure I understand what you wrote back. If you're using the autoEnableBackend feature, it stops trying to enable backends as soon as one fails? Is that correct? If so, it answers my question.
If not, here's what I'm trying to do: I have two backends in my Virtual DB. I start the controller with autoEnable on. It tries to connect to the first backend and because there's no network connection (I broke the physical connection) it reports unable to connect and therefore unable to enable. The controller then appears to not even try to connect to the other backend. My thinking is that it would be better for auto-enable to try to enable every backend regardless of failure (assuming you're using a RAID system that doesn't require all backends to work, like RAIDb-1). If it stops as soon as one failure is found, you lose your entire DB functionality even if only one backend has a problem. For example, if I have 10 backends and the first one in my list in the Virtual DB config fails, I get no database. But, if I have RAIDb-1 and I just want to start up with the other 9 functioning, I can't unless I manually enable all the backends. I do understand the push for manual enabling, as it is safer, but if there's an auto-enable feature, why wouldn't it try to start everything it can and just report any failures? In our project, if the first backend is OK and the second one fails, the controller still uses the first backend and everything is fine from our application's perspective. If the first backend fails and the second one is OK, I would expect the controller to simply use the second backend. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Emmanuel Cecchet Sent: Thursday, October 02, 2008 4:48 PM To: Sequoia general mailing list Subject: Re: [Sequoia] Sequoia not trying subsequent backends Hi Jonathan, I am not sure to understand what you are talking about. Are you talking about the autoEnableBackend feature of the controller that stops as soon as it cannot enable one backend? It is a good practice to load configuration files and enable backends remotely to have a good control on what is happening. But the auto-enable should auto-enable all backends that have a valid checkpoint in the recovery log. Let me know which feature looks dysfunctional. Thanks for the feedback, Emmanuel > I just found a major problem with our use of Sequoia and want to make > sure I'm understanding this correctly. > We have the controller automatically start our virtual database and > enable the backends. We have two backends in our virtual DB. If the > first backend succeeds in connecting and the second backend fails, the > system continues working properly (without backed-up data, of course). > However, if the first backend listed in the virtual DB config fails, > Sequoia does not appear to try to connect to the second backend. This > is a problem for us. > > Is there any way to get Sequoia to continue trying to connect to > backends once it's come across a failure? Or am I going to have to > manually start and enable the backends through the code? I'd like to > avoid this, as it adds more development time to our project, which we > can't afford. > Thanks, > Jonathan Stockho > Software Developer > Swisslog Healthcare Solutions > 10825 E. 47th Avenue > Denver, CO 80239 > Phone: 303-373-7814 > FAX: 303-373-7872 > e-mail: [EMAIL PROTECTED] > Internet: www.swisslog.com <http://www.swisslog.com> > ------------------------------------------------------------------------------------ > > *About Swisslog * > Swisslog designs solutions in logistics automation that greatly reduce > the manual flow of materials and associated information within > healthcare facilities. > This message may contain legally privileged or confidential > information and is therefore addressed to the named persons only. The > recipient should inform the sender and delete this message, if he/she > is not named as addressee. The sender disclaims any and all liability > for the integrity and punctuality of this message. The sender has > activated an automatic virus scanning, but does not guarantee the > virus free transmission of this message. > ------------------------------------------------------------------------ > > _______________________________________________ > Sequoia mailing list > [email protected] > https://forge.continuent.org/mailman/listinfo/sequoia -- Emmanuel Cecchet FTO @ Frog Thinker Open Source Development & Consulting -- Web: http://www.frogthinker.org email: [EMAIL PROTECTED] Skype: emmanuel_cecchet _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia This message may contain legally privileged or confidential information and is therefore addressed to the named persons only. The recipient should inform the sender and delete this message, if he/she is not named as addressee. The sender disclaims any and all liability for the integrity and punctuality of this message. The sender has activated an automatic virus scanning, but does not guarantee the virus free transmission of this message. _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia
