PDI Error occured while trying to connect to the database

Question

I got the following error while executing a PDI job. I do have mysql driver in place (libext/JDBC). Can some one say, what would be the reason of failure? Despite the error while connecting to DB, my DB is up and I can access it by command prompt.

Error occured while trying to connect to the database

Error connecting to database: (using class org.gjt.mm.mysql.Driver)
Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
ERROR 03-08 11:05:10,595 - stepname- Error initializing step [Update]
ERROR 03-08 11:05:10,595 - stepname - Step [Update.0] failed to initialize!
INFO  03-08 11:05:10,595 - stepname - Finished reading query, closing connection.
ERROR 03-08 11:05:10,596 - stepname - Unable to prepare for execution of the transformation
ERROR 03-08 11:05:10,596 - stepname - org.pentaho.di.core.exception.KettleException:
We failed to initialize at least one step.  Execution can not begin!

Thanks

Answer 1

Is this a long running query by any chance? Or; in PDI world it can be because your step kicks off at the start of the transform, waits for something to do, and if nothing comes along by the net write timeout then you'll see this error.

If so your problem is caused by a timeout that MySQL uses and frequently needs increasing from the default which is 10 mins.

See here:

http://wiki.pentaho.com/display/EAI/MySQL