ENGINE: Error during graph initialization(null)

CloverDX Platform
1

Hi,

Some of the graphs I’m working with report “ENGINE: Error during graph initialization(null)” the Eclipse “Problems” tab.

How can I find out more details about exactly what is causing this problem.

thanks,
Paul

2

Hello,
do the graphs are complete? Do they run?
Could you attache such graph?

3

Hi Agata,

the graph I’ve got does run.

I’ve been trying to put together a sample graph demonstrating this. The graph uses custom components - some I’ve written and some from a 3rd party. I haven’t been able to pin down exactly what component is causing the problem - but now suspect that it may be a class loading related issue, though am having trouble working out why. Possibly the GUI is unable to load the dependent jars my components require?

However, I have manged to create a graph that reports the “ENGINE: Error during graph initialization (null)” message, though in this case the graph doesn’t run. This is a simple graph (Universal Data Reader → Universal Data Writer) with NO meta-data on the joining edge. Putting meta-data on the edge clears the error message. Though in this trivial case it is easy to determine what the problem is when there are only two nodes and one edge.

The graph I have that does report the message, does have meta-data on all the edges and does run!

btw, currently using CloverETL GUI 1.10.1

thanks,
Paul

4

Hi,
it can be caused by not properly implemented checkConfig method. In this method there is thrown NullPionterException. In new version it should work better: instead NPE should be thrown ComponentNotReadyException with sensible message.

5

Hi,

I think I know what was happening. My component deployed as a plugin was being correctly detected up by the Clover Engine - the graph ran fine. The clover engine made available jars supplied by the provider of 3rd party components (also deployed as a plugin) to my component.

However, I think in the GUI, when it was trying to create an instance of my component so that checkConfig could be called, a dependency on one of the 3rd party jars was not being met. A different class loader approach being used? I solved this by deploying second copies of the jars from the 3rd party components and putting appro. entries in the plugin.xml (plugin/runtime/library path=…)