Neo4j Server vs Embedded mode

Question

I wanted to know exactly what is meant by neo4j server and the embedded mode. Even i gone through the post Neo4j Server vs. Embedded. But i dint get clearly those concepts. I have installed neo4j 2.1.1 on windows 64bit machine which is a neo4j server. So when neo4j embedded mode will come into picture?

Also how can we switch between embedded mode to server mode or vice-versa?

When i was working with mysql to neo4j migration(using batch-import), after importing the nodes and relationships into neo4j getting a message in a messages.log file as below:

Clean shutdown on BatchInserter(EmbeddedBatchInserter[C:\Users\Neo4j\t2.db]) 

How embedded is appearing here if i have installed neo4j server ? So please clarify these queries.

Thanks

Answer 1

Embedded databases run inside of your application, meaning they're in the same JVM as your application. In general, with embedded databases you'll do direct database access or cypher queries. There are a lot of pros and cons here - one of the cons is that your JVM process locks the database; you can't have a bunch of different applications in different JVMs accessing the same embedded database at the same time. The pro is direct access.

When you're running a server, usually that means you're using the web admin components which also provide a set of RESTful services. The pro of this is that it's in a different JVM. Meaning you could access it more easily from other programming languages, over the network, and so on. You could have many applications in many JVMs all talking to a server instance via RESTful services. Generally access isn't as fast, but it's more flexible. When you run it this way though, direct access to the graph inside of a java application (using the Neo4J API) is off limits.

If you want to run the web admin/GUI stuff and RESTful services from within an embedded database, you can do that. See these instructions for how.

Here's a code snippet: what you need is the WrappingNeoServerBootstrapper.

AbstractGraphDatabase graphdb = getGraphDb();
WrappingNeoServerBootstrapper srv;
srv = new WrappingNeoServerBootstrapper( graphdb );
srv.start();
// The server is now running
// until we stop it:
srv.stop();