[Date Prev][Date Next]
Re: account balances
søn, 2002-11-24 kl. 20:36 skrev Ryurick M. Hristev:
> > 4: IMHO, anyone who puts cash balances in a replicable,
> > organization-wide directory database with absolutely no guarantee of
> > concurrency needs an immediate trip to the shrink.
> Unless there is my case where I have just to update once a day
> the balance from upstream and only be able to read it, not update it.
> Second: it doesn't have to be _maintained_ by the ldap server,
> just to be _read_! I.e. I assume one could have a DB in the backend
> and use LDAP just to _read_ the values. But in order to be able
> to read the values trough the LDAP protocol it must have a schema
> entry somewhere. At least this is my understanding.
> Third: in a "one master, several slaves" only the masted may be
> allowed to update the records so the problem of write concurrency
> does not exists.
> Could somebody tell me please if I am wrong and why ?
I have a balance of a million Euros at my bank (or anywhere). My bank
(or anyone) uses an ldap master and 3 slaves somewhere else in the
country. I take out 999,999 Euros and immediately arrange for the master
to crash. I go to another bank that uses my bank's ldapserver for its
account data, but because the master is down, it gets its data from one
of the slaves. I then take out another 999,999 Euros. I've arranged for
that slave to crash too ...
People who look after other peoples' money just do not put any account
details in ldap directory servers.
When all's said and done ...
there's nothing left to say or do.