H2 database error: Database may be already in use: "Locked by another process"

I am trying to use the H2 database from a Java application.

I created the database and its tables through the H2 Console and then I try to connect from Java using

Connection con = DriverManager.getConnection("jdbc:h2:~/dbname", "username", "password");

However I receive the following error:

> Exception in thread "main" org.h2.jdbc.JdbcSQLException: Database may be already in use: "Locked by another process". Possible solutions: close all other connection(s); use the server mode [90020-161]

I tried to delete the `dbname.lock.db` file but it is automatically re-created.

How can I unlock the database to use it from my Java program?

H2 is still running (I can guarantee it). You need to use a TCP connection for multiple users such as ->

<property name="javax.persistence.jdbc.url" value="jdbc:h2:tcp://localhost/C:\Database\Data\production;"/>
OR

DriverManager.getConnection("jdbc:h2:tcp://localhost/server~/dbname","username","password");

It also means you need to start the server in TCP mode. Honesetly, it is pretty straight forward in the documentation.

Force kill the process (javaw.exe for Windows), and make sure that any application that might have started it is shut down. You have an active lock.

You can also visit the "Preferences" tab from the H2 Console and shutdown all active sessions by pressing the shutdown button.

I'm using h2db with a test T24 tafj application, I had the same problem but I managed to resolve it by identifying the application that is running h2 (launched when I attempted to setup a database connection).

ps aux|grep java

will give output as:

sysadmin 22755 3.2 0.1 5189724 64008 pts/3 Sl 08:28 0:00 /usr/java/default/bin/java -server -Xmx2048M -XX:MaxPermSize=256M -cp h2-1.3.175.jar:/r14tafj/TAFJ/dbscripts/h2/TAFJFunctions.jar org.h2.tools.Server -tcp -tcpAllowOthers -baseDir /r14tafj/t24/data

now kill this with its process id:

kill -9 22755

and at last remove the lock file:

rm -f dbname.lock.db

I ran into similar problems running with ORMLite from a web application. I initially got stuck on the syntax to use server mode in the url. The answers above helped with that. Then I had the similar user/password error which was easier to figure out. I did not have to shut anything down or erase any files. The following code worked:

protected ConnectionSource getConnectionSource() throws SQLException {
String databaseUrl = "jdbc:h2:tcp://localhost/~/test";
return new JdbcConnectionSource(databaseUrl,"sa","sa");
}

To use H2 in server mode on wildfly, I Modifed connection-url in standalone.xml

<datasource jndi-name="java:jboss/datasources/ExampleDS" pool- name="ExampleDS" enabled="true" use-java-context="true">
<connection-url>jdbc:h2:tcp://localhost/~/test</connection-url>
…
</datasource>

Ran into a similar issue the solution for me was to run `fuser -k 'filename.db'` on the file that had a lock associated with it.

Hope this helps!

Simple step: Go to the task manager and kill the java process

then start your apllication

I had the same problem.
in Intellj, when i want to use **h2** database when my program was running i got the same error.
For solve this problem i changed the connection url from

spring.datasource.url=jdbc:h2:file:~/ipinbarbot
to:

spring.datasource.url=jdbc:h2:~/ipinbarbot;DB_CLOSE_ON_EXIT=FALSE;AUTO_SERVER=TRUE
And then my problem gone away. now i can connect to "ipinbarbot" database when my program is.
If you use Hibernate, also don't forget to have:

spring.jpa.hibernate.ddl-auto = update

**goodluck**

You can also delete file of the h2 file database and problem will disappear.

jdbc:h2:~/dbname means that file h2 database with name db name will be created in the user home directory(~/ means user home directory, I hope you work on Linux).

In my local machine its present in: /home/jack/dbname.mv.db I don't know why file has a name dbname.mv.db instead a dbname.
May be its a h2 default settings.
I remove this file:

rm ~/dbname.mv.db

OR:

cd ~/
rm dbname.mv.db

Database dbname will be removed with all data. After new data base init all will be ok.

I got clue from Saman Salehi above.
My usecase:
Preparing REST application for client-side load balancing(running two JVM instances of REST). Here my MVC application will call this REST application that has ActiveMQ backend for DATA.
I had the problem when I ran two instances of REST application in eclipse and trying to run both instances at the same time with the following configuration

spring.datasource.url=jdbc:h2:file:./Database;
spring.jpa.properties.hibernate.hbm2ddl.auto=update

After adding DB_CLOSE_ON_EXIT=FALSE;AUTO_SERVER=TRUE

spring.datasource.url=jdbc:h2:file:./Database;DB_CLOSE_ON_EXIT=FALSE;AUTO_SERVER=TRUE
Both instances are running and showing in Eureka dasboard.

Don't close the database when the VM exits : jdbc:h2:<url>;DB_CLOSE_ON_EXIT=FALSE

Multiple processes can access the same database without having to start the server manually ;AUTO_SERVER=TRUE

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