@engin_arlak, you are confusing conversations with service invokes. Conversation are loosely defined as steps that can be executed in separate threads anyway. Under no circumstance can two transformers in the same MAP step execute on two different servers. If you have written code with checkpoints, what can happen is that the MAP step fails after the execution of one transformer, the recovery happens on another server and the entire MAP step executes on another server. But there is no way to add a checkpoint in the middle of a MAP step.
Again, I am not directly referring to transformers. I don’t know if they can execute in paralel or not. But I was asked that question in job interviews several times in the past. I don’t want to restart this whole thread. It will be a big loop if I do. Personally I never liked the idea using the transformers as paralel service invokers anyway. We are way too off topic in this thread and we are getting more so each day. I suggest creating another topic and move this conversation elsewhere if additional comment is necessary.
I edited the post that sounded like I observed transformers executed in paralel. This is incorrect, I don’t know if transformers run in parallel or not. It is an interview question that was frequently asked me and I never checked if they executed in parallel or not. According to me its a workaround and it should be avoided.