cayenne-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Aristedes Maniatis <...@maniatis.org>
Subject Re: NuoDB Cayenne Adaptor
Date Thu, 23 Aug 2012 08:14:26 GMT
On 23/08/12 5:41pm, Malcolm Edgar wrote:

> Is this the correct approach. The reason I am using Cayenne 3.0.x, is so I
> can perform testing against our applications, which I think is a good way
> of verifying this code.

I don't recall seeing much change in the bits of code you are touching from 3.0 to the current
trunk. But Andrus will know.


> I can't really comment about how they implement ACID, there is the issue of
> latency and the speed of light!  I think their use of MVCC helps with this
> type of problem, which then becomes an application problem.

I watched their video. Very interesting. Like Andrus, I also don't see how they can accomplish
ACID and have asynchronous communication between nodes. Seems like a layer of magic is missing
somewhere, but I guess we'll all know more when they release their product and specs.


> The applications I develop don't have a lot of contention, my main concern
> is about availability. I haven't figured out how to do automatic fail over
> yet, beyond loosing a connection to a Transaction Engine (TE) and then
> going back to a Broker to establish a new connection to a (TE).  My concern
> is if you loose a TE and Broker, then I have to write the code to reconnect
> to another Broker.

For mysql you just use this in the JDBC connection

     jdbc:mysql:replication

http://dev.mysql.com/doc/refman/5.1/en/connector-j-reference-replication-connection.html

But of course, mysql master-master replication sucks. And promoting a slave to master requires
scripting outside of mysql itself. At least the failover part in JDBC is easy.


Cheers
Ari

-- 
-------------------------->
Aristedes Maniatis
GPG fingerprint CBFB 84B4 738D 4E87 5E5C  5EFA EF6A 7D2E 3E49 102A

Mime
View raw message