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
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