Hi,
A while back I struggled to connect to a MIMER RDBMS - i know this isn't DB2, but the instructions should be transferable I would've thought. The instructions I wrote for myself to get it working are below (I've altered them slightly for your scenario)
1. Install appropriate JDK version (have you checked the version of the driver .jar file you are using is correct relative to the version of Java installed? - this was one of the problems I had - the JDK version was incorrect relative to the driver file's published java version)
2. Ensure PATH environment variable doesn't point to another version of Java (at command prompt run 'echo %PATH%' to check this)
3. Set JAVA_HOME to appropriate JDK's bin directory (e.g. C:\jdkv1.8\bin) - e.g. at command prompt run 'set JAVA_HOME=%JAVA_HOME%;C:\jdkv1.8\bin'
4. At command prompt run 'java -version' to ensure it's picking up appropriate JDK rather than other versions of Java
5. Download the jdbc driver file (db2whatevs.jar) and copy this to 'C:\Program Files\SmartBear\ReadyAPI-2.x.x\bin\ext'
6. Create or update the CLASSPATH environment variable, pointing to the location of the .jar file. Run the following command via command prompt 'set CLASSPATH=%CLASSPATH%;C:\Program Files\SmartBear\ReadyAPI-2.x.x\bin\ext'
7. There appear to be 2 different DB2 connection strings defined in the JDBC preferences in ReadyAPI! v2.4.0 - have you tried both?
8. Final thought - double check that the connection string you're using matches the pattern in the JDBC config?
when I was setting up my connection I was getting a 'failed to initialize connection' response because my jdbc connection string was incorrect - perhaps this is why you are getting the same response also?
hope this helps!
cheers,
richie