We are at architectural/design phase (cycle zero). No decision has yet
been made. Is there an example for invalidating cache somewhere?
bye,
Borut
On 31.7.2006 20:29, Tore Halset wrote:
> Hello.
>
> On Jul 31, 2006, at 17:52, Borut Bolčina wrote:
>
>> I need an advice on using Cayenne in an environment where two
>> PostgeSQL databases are configured to replicate from each other for
>> failover capability.
>
> Are you using Sequoia[1] or slony[2] or creating your own solution?
>
>> I am thinking of two Cayenne enabled applications (load distribution)
>> which insert records in one of those two databases. Application one
>> (A1) inserts in database one (DB1) and application two (A2) inserts
>> in database two (DB2).
>>
>> The insertion, deletion or update will cause Java triggers in
>> PostgreSQL to call appropriate Java method in the application. If for
>> any reason one of the databases is down for some time, the
>> replication mechanism will bring the second database up-to date which
>> will trigger invocations of the Java methods, so the second
>> application will be in the correct state also.
>>
>> As long as triggers do not modify records, everything should be ok
>> with Cayenne. In case, which I don't foresee now, the records will be
>> modified on database level, all DataContexts should be invalidated,
>> am I right?
>
> Cayenne has its own way of syncronizing cache[3] between app
> instances. You could also invalidate cache manually.
>
> - Tore.
>
> [1] http://sequoia.continuent.org/HomePage
> [2] http://gborg.postgresql.org/project/slony1/
> [3] http://cwiki.apache.org/CAYDOC/configuring-caching-behavior.html
>
>
-- bLOG <http://www.delo.si/blog/borutb/> -- Naključna *izjava tedna* iz tednika Mladina:
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