HowTo: Camunda (Tomcat) with MySQL

[Carsten Duch]

I've just switched my camunda BPM (Tomcat) testing environment to MySQL.
I've found no documentation for this, so I've wrote a short HowTo.

1. create MySQL Database
Open a terminal with a MySQL Console as root.
copy&paste the following lines into the console to create a database with the name camundabpm and the password MYSECRETPW (you should change it ...).

CREATE DATABASE IF NOT EXISTS camundabpm;
GRANT ALL ON camundabpm.* TO camundabpm@'localhost' IDENTIFIED BY 'MYSECRETPW';
GRANT ALL ON camundabpm.* TO camundabpm@'localhost.localdomain' IDENTIFIED BY  'MYSECRETPW';
GRANT ALL ON camundabpm.* TO camundabpm@'127.0.0.1' IDENTIFIED BY 'MYSECRETPW';

Close the mysql console and cd into CAMUNDA_DIRECTORY/sql/create and use the following comands in your terminal for the table creation:

$ mysql camundabpm -u camundabpm -pMYSECRETPW <  mysql_cycle_7.0.0-alpha1.sql
$ mysql camundabpm -u camundabpm -pMYSECRETPW <  mysql_engine_7.0.0-alpha1.sql
$ mysql camundabpm -u camundabpm -pMYSECRETPW <  mysql_identity_7.0.0-alpha1.sql

2. install MySQL Connector
download the latest version (currently 5.1.24)  of the connector http://mvnrepository.com/artifact/mysql/mysql-connector-java
copy the file mysql-connector-java-5.1.24.jar to the CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/lib/ directory

3. change configuration files to work with MySQL instead of H2

open the files:
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/tasklist/META-INF/maven/org.camunda.bpm.tasklist/camunda-tasklist/pom.xml
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/cycle/META-INF/maven/org.camunda.bpm.cycle/camunda-cycle/pom.xml
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/cockpit/META-INF/maven/org.camunda.bpm.cockpit/camunda-cockpit/pom.xml
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/engine-rest/META-INF/maven/org.camunda.bpm/camunda-engine-rest/pom.xml

and replace the lines:

<dependency>
  <groupId>com.h2database</groupId>
  <artifactId>h2</artifactId>
  <scope>provided</scope>
</dependency>

with:

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.24</version>
</dependency>

next, open the files:
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/cycle/META-INF/context.xml
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/conf/server.xml

and replace the lines:

driverClassName="org.h2.Driver"
url="jdbc:h2:./camunda-h2-dbs/process-engine;MVCC=TRUE;TRACE_LEVEL_FILE=0"
username="sa"  
password=""

with:

driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/camundabpm?autoReconnect=true"
  username="camundabpm"  
  password="MYSECRETPW"

4. start your server

go to CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/bin and start the server with the command:

$ ./startup.sh

After the startup, you can take a look into your MySQL Database, inside the table ACT_ID_USER there should be 4 entries for "John","Mary","Peter" and "demo". They are auto-created by the TasklistDemoData.class and this is your confirmation that camunda BPM now uses MySQL instead of H2.

Congratulations!

[Daniel Meyer]

Hi Carsten,

AWESOME! Thanks. We will release an installation guide shortly, maybe we can integrate some of this information there. 

Just one question:

In Step 3 you modify the deployed maven pom.xml files. Why is this necessary?

Chreers,

Daniel

[Carsten Duch]

I just switched from php development to java with play framework last winter.
So I'm new to Maven, I didn't know which files are autogenerated and which not, so I changed everything with "H2" in it :-)

Does this mean that if you change the following files:
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/webapps/cycle/META-INF/context.xml
CAMUNDA_DIRECTORY/server/apache-tomcat-7.0.33/conf/server.xml

the pom.xml files are automatically rewritten? That's a lot easier.

[nire....@gmail.com]

Hi Carsten,

Nice how-to!

As far as I know, changing the any maven coordinates in the poms is not neccessary. Those are just left over for reference (of the expected dependencies) when the maven artifacts are compiled during `mvn install` and have no impact on actual class loading.

I believe it is sufficient to add the mysql drivers (step 2) and reconfigure the database (last step in 3).

Or did you experience any issues with that?

Cheers,

Nico

[esie...@gmail.com]

Hi Carsten,

Another point to add to this is that the h2 JAR should be removed from the tomcat7 lib. Simply renaming it, say, 'mv h2-1.3.168.jar h2-1.3.168.jar.off', works fine. If you don't do this, camunda will still try to create working directories all over the place, such as:
/tmp/hsperfdata_tomcat7/ (replace 'tomcat7' with the userID running your tomcat7 service.)
~tomcat7/camunda-h2-dbs/
and
/usr/share/tomcat7c/bin/camunda-h2-dbs/

Edward Siewick

[christian...@gmail.com]

Hi Carsten,

as Nico pointed out, it is not necessary to do the following stuff, because they are jus meta information generated during the maven build. It is simply ignored during runtime.