-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Alan,
Alan Chaney wrote: > As far as the database side of it goes it seems to me that much of it is > a question of making the 'live-update' a design requirement for any > upgrades. You have to make it possible for the changes to the database > to 'co-exist' and then update the live database independently of the > application. When the new tables are ready, deploy your new application > and (hopefully) go home smiling. This is the "right" way to do it, but it's a complete PITA to implement. :( > I'd be interested to hear from people who have clustered solutions. Once > again I suspect there may be problems with trying to sustain sessions > across the upgrades. We don't do this (operating only in the US for now), but one way to do this is to have multiple clusters, and multiple clustered databases using replication across clusters. You remove one of the db clusters from the replication schedule and one of the app server clusters from normal service, and let your clients move to other machines. Then, you upgrade the segregated cluster while your users use the machines and databases running your old stuff. Bring this new cluster online and let users start using it. Repeat with the other clusters, and then resume db replication. It's tricky, but possible, especially if your users will be okay if some of them run the old version while others get the new version -- /and/ if they don't need to share data immediately (i.e. the time delay before all databases are sync'd up is tolerable). Then again, there's always the weekend, when most folks aren't working, anyway ;) - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkjSfrUACgkQ9CaO5/Lv0PA90gCfY6mqVVdb80FOjoyz95Dlb5Lt +2gAni0v8tzPtG5IoDSAC37D0V4FiPx+ =lTF9 -----END PGP SIGNATURE----- --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
