I tried to run my previous workflow using spark, however an error appears
Spark context was created by version 2.1.0.v201709091016 of the KNIME Extension for Apache Spark, but you are running 2.2.0.v201712021420. Please destroy and reopen this Spark context or use a different one.
how should I deal with this?
Thank you in advance.
with your KNIME you also updated the Spark extension (now called "KNIME Extensions for Apache Spark"). Whenever you update the Spark extensions you cannot work with your existing Spark context anymore, so either you destroy it (Destroy Spark Context node) or you create a new one with a different name (Create Spark Context node).
A Spark context is supposed to be a temporarysession. It is best practice to only keep it open while you are working with it. When you don't (e.g. when you are not at work), you save your current results to persistent storage (HDFS) and destroy the context.