Emmanuel, Thanks for your very quick answer.
Unfortunately, after some tests I encountered a strange behaviour. I have two database DB1 and DB2. I stop the database DB2, DB2 is always enabled because sequoia cannot know that I stopped the second DB. I execute some read requests. The first one is sent to the de db1 ==> OK The second one is sent to the db2 ==> KO (I just stopped the db). But the result of my query is null :( It is like my second request was not redirected to the valid DB1 ? Did you already encounter this ? Xavier. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Emmanuel Cecchet Sent: vendredi 17 novembre 2006 17:17 To: Sequoia general mailing list Subject: Re: [Sequoia] Questions Raidb1 load balancer Xavier, > I configured the load balancer with the completion policy > WaitForCompletionPolicy.FIRST > > So, the raidb1 load balancer executes each write request on each > backends and wait for the success of one of them. > Yes. In fact it waits for the success of both of them because if one fails but the other succeeds, the failed backend must be disabled. However, the result is returned to the client as soon as one node is successful. > But what about the read requests ? > It one of the read request is sent to one invalid backend, is the read > request redirected to the second backend ? > A read request is only sent to an active backend (not disabled). If that backend happened to fail during the query execution, it is retried automatically on another backend. Hope this clarifies things, Emmanuel -- Emmanuel Cecchet Chief Scientific Officer, Continuent Blog: http://emanux.blogspot.com/ Open source: http://www.continuent.org Corporate: http://www.continuent.com Skype: emmanuel_cecchet Cell: +33 687 342 685 _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia _______________________________________________ Sequoia mailing list [email protected] https://forge.continuent.org/mailman/listinfo/sequoia
