Unable to run Spark Predictor



I am trying to run a Spark Predictor using a trained Spark Linear Regression Learner, but the Spark Predictor component seems to fail every time I execute it.
This is the error that is printed from KNIME’s console:
Execute failed: akka.pattern.AskTimeoutException: Ask timed out on [Actor[akka://JobServer/user/data-manager#1019598049]] after [3000 ms]. Sender[null] sent message of type “spark.jobserver.DataManagerActor$StoreData”. (RestoredThrowable)

After inspecting /var/log/spark2-job-server/spark-job-server.log, turns out there was this exception:
ERROR ka.actor.OneForOneStrategy [] [akka://JobServer/user/data-manager] - /tmp/spark2-job-server/upload/knime-sparkModel7134388612124129131.tmp-2018-07-12T14_46_39.707+07_00.dat (No such file or directory)
java.io.FileNotFoundException: /tmp/spark2-job-server/upload/knime-sparkModel7134388612124129131.tmp-2018-07-12T14_46_39.707+07_00.dat (No such file or directory)

If it helps, I also tried looking at /var/log/spark2-job-server//spark-job-server.log, but there were nothing inside the log file relating to the exception (the log just ends at “Linear Regression With SGD done” and “Job finished OK


Hi @veee

in /var/log/spark2-job-server/ are there any folders called “jobserver-~”?

If yes: They contain the actual logs for the Spark contexts (one context = one folder). Please locate the one for the context with the failed job and send it to me via private message, so I can take a look.

If not, then Spark Jobserver is not correctly set up. Have you already taken a look at the installation guide?




Yes, there is a jobserver-~ folder. What I meant to say in my previous post was that I took a look at /var/log/spark2-job-server/jobserver-~/spark-job-server.log, but nothing in the log file contains something that relates to the exception.
This time however, there are additional messages containing several “removed broadcast”.

How do I send a private message by the way?