cayenne-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Borut Bolčina <...@najdi.si>
Subject Re: Database replication and caching
Date Wed, 02 Aug 2006 06:41:59 GMT
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:

Mime
View raw message