On 02-05-11 10:02, newnomad wrote: > If one installs trytond on a server in the cloud (not intranet) Is > there a prescribed procedure for offering a fallback solution to a > syncronised local DB on all the users machines, so their clients can > connect to that local DB when no internetconnection is available? > Pretty much like IMAP mail, or google apps desktop.
I assume you are referring to disconnected mode. IMAP in and off itself doesn't support anything like that! Of course, there are several IMAP-clients that support disconnected mode by basically downloading the complete IMAP store or selected parts of it to your PC. But I would trust the mailbox state if many disconnected clients start updating messages in a mailbox. I'm pretty sure this would quite often trigger complete re-downloads of complete mailboxes. The problem with asynchronized master-master replication of databases between clients - that is without using some kind of 2-phase commit algorithm - is that it is impossible to avoid key collisions. To solve this you need some kind of conflict resolution in the replication layer. Very, very tricky to do. I know Sybase offers solutions for just this usage pattern for the mobile market; async replication, conflict resolution, disconnected mode, etc. But afaik none of the open-source RDBMS offer anything like that. -- ________________________________________________________________ Paul Stevens paul at nfg.nl NET FACILITIES GROUP GPG/PGP: 1024D/11F8CD31 The Netherlands________________________________http://www.nfg.nl -- [email protected] mailing list
