Re: backup web server - sync - transaction logs
On Mon, 28 Feb 2005, Roberto C. Sanchez wrote:
> >>So let's say both boxes are up and serving web pages. And part of that
> >>includes a mysql DB where websurfers can input their names/email
> >>addresses.
> >
> Wow. For a setup like this you probably want Postgres and not MySQL.
...
> My understanding is that there is an effort underway to get no kidding
> enterprise-level replication into Postgres and that they are having
> good results up to now. Even to the point that some sites have it in
> produciton. I don't know the details, but a Google search for postgres
> and repication would probably yield some good information.
you cannot "replicate" per se ..
you'd need to merge changes from www1:db into www2:db
and merge changes from www2:db into www1:/db
best way is to create a transaction log ... and replay
the transaction log against each db to be updated
- your db of choise must support "transaction" logging
and reply
- but one also has to make sure the transaction log
doesn't have the equivalent of "rm -rf" for each db record
which means if you're paranoid like oracle, you keep 9 live
databases on which to record the transactions
- pretend it is a credit card transaction
- it must be done securely
- it must not duplicate the records ( purchases )
- it must not drop the records ( not charge them for purchases )
- it must have an audit log to show why the entry exists
- it must be cloned into LA office and NYC office and london
office
- fun stuff
c ya
alvin
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