On 15/08/2013 12:19, Olivier Nicole wrote: > I have been assigned to offer HA on a 3 tiers architecture. > > Data storage tier will be MySQL, so replication is easy. > > HA should be implemented only on the Data storage tier, Active/Active, > but one of the sites is remote! > > When everything is working, each application accesses the local MySQL > tier, but when the local MySQL becomes unavailable, it should be able > to automatically move to the other database server. > > I have no access to the application, so I cannot modify it to test if > local MySQL is working. So I should have an HA mechanism that enforces > changing the IP address on the database server. > > If both servers are installed at different places, with different > addresses, would there be a way beside establishing an IP tunnel/VPN > between both places to have all machines in a single subnet? > > An image is here http://www.cs.ait.ac.th/~on/HA.gif > > I am really bothered by the IP tunnel, but that's the only way I see to keep > HA. > > Any idea welcome.
Depending on the technology use in you middle layer, it may be quite simple. Some application languages, eg Java allow you to specify a list of servers in a DB connection string. The server names will be tried in order until a successful connection is made. Other languages may provide a similar facility, or it should be pretty easy to code up with minimal intervention in your codebase required. Cheers, Matthew _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"