High availability and other pratical questions

Hi,

I've just started developing a mobile app which will use a server side, hopefully handling a lot of processing and traffic. I was inteding to use TomEE+ with built-in OpenJPA and Postgres DB, initially on one master server but as it grows more master servers will be set (in different geo locations/data centers) using some data sync mechanism between them.

Now that i've met ObjectDB I want to check the option using it instead of postgres so I have few questions regarding it:

1. As the embedded DB seems to be with superior performance would you recommend using it with TomEE+ instead of creating a 2 TomEE+ frontend servers cluster with ObjectDB server as a backend DB? 
2. Does DB backup backs all objects including indexes? If yes, is there a way to backup data only? And. is there a way to backup specific entities only?
3. What is the overhead of online backup?
4. What is the overhead of the Transaction Replayer?

Many thanks,

Amit

Embedded mode is faster, so embedding ObjectDB in the main Tomcat server will improve performance. You should be able to access embedded ObjectDB from other Tomcat servers (and also replicate that database, etc.) but currently this is an undocumented feature (ask for details if it becomes relevant before this feature is released).

Currently ObjectDB online backup backs up the entire database including all the entities and indexes.

The overhead of online backup and transaction recording (that are used later for replaying) is relatively low, but you will have to check it with your own application.

Hi,

Thanks for the fast reply and answers, any estimation when the embedded DB high availability with replication feature will be officially released (and documented)?

Thanks,

Amit

It is expected to be soon. The feature is already implemented. More feedback from users that will try it is required.

Can you confirm if replicated embedded for client is available yet? that is what I have been waiting for before trying the embedded server replication, I would prefer to have all my master/slave in the same state(ie embedded or non-embedded).

The master database can use embedded mode but the replicated slaves not (yet).