Re: AppScale backend datastore (NoSQL again kind of)

Regards, Ross.
Dimitri Fontaine gave a excellent talk in the last PgCon about the migration of Fotolog from MySQL to
PostgreSQL with amazing advices around this, so you can contact him for his advice.

Hey PostgreSQL speed demons -
At work, we're considering an AppScale deployment (that's the Google App Engine
roll-your-own http://appscale.cs.ucsb.edu/). It supports multiple technologies
to back the datastore part of the platform (HBase, Hypertable, MySQL Cluster,
Cassandra, Voldemort, MongoDB, MemcacheDB, Redis). Oddly enough, in performance
tests, the MySQL Cluster seems like the general winner (their tests, we haven't
done any yet)

So, my immediate thought was "How hard would it be to replace the MySQL
Cluster bit w/ PostgreSQL?" I'm thinking hot standby/streaming rep. May or may
not need a pooling solution in there as well (I need to look at the AppScale
abstraction code, it may already be doing the pooling/direction bit.)

It depends of many factors:
- size of the MySQL cluster
- size of the involving data, etc

For the pooling solution, I recommend you to see PgBouncer, it´s a great
project widely used for this topic.

Any thoughts from those with more experience using/building PostgreSQL clusters?
Replacing MySQL Cluster? Clearly they must be using a subset of functionality,
since they support so many different backend stores. I'll probably have to
set up an instance of all this, run some example apps, and see what's actually
stored to get a handle on it. The GAE api for the datastore is sort of a ORM,
w/ yet another query language, that seems to map to SQL better than to NoSQL,
in any case. There seems to be a fairly explicit exposure of a table==class
sort of mapping.

Ross

Best wishes