h2 in-memory tables, remote connection

database jdbc embedded-database h2
Carolyn picture Carolyn · May 4, 2010 · Viewed 18k times · Source

I am having problems with creating an in memory table, using H2 database, and accessing it outside of the JVM it is created and running in.

The documentation structures the url as jdbc:h2:tcp://<host>/mem:<databasename>

I've tried many combinations, but simply cannot get the remote connection to work. Is this feature working, can anyone give me the details of how they used this.

Answer

RealMan picture RealMan · Jun 23, 2017

None of the solutions mentioned so far worked for me. Remote part just couldn't connect.

According to H2's official documentation:

To access an in-memory database from another process or from another computer, you need to start a TCP server in the same process as the in-memory database was created. The other processes then need to access the database over TCP/IP or TLS, using a database URL such as: jdbc:h2:tcp://localhost/mem:db1.

I marked the crucial part of the text in bold.

And I found a working solution at this guy's blog:

The first process is going to create the DB, with the following URL:

jdbc:h2:mem:db1

and it’s going to need to start a tcp Server:

org.h2.tools.Server server = org.h2.tools.Server.createTcpServer().start();

The other processes can then access your DB by using the following URL:

"jdbc:h2:tcp://localhost/mem:db1"

And that is it! Worked like a charm!

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