How to access Spark Context in predict?

[Hasan Can Saral]

Hi!

I am trying to query Event Server with PEventStore api in predict method to
fetch events per entity to create my features. PEventStore needs sc, and
for this, I have:

- Extended PAlgorithm
- Extended LocalFileSystemPersistentModel and
LocalFileSystemPersistentModelLoader
- Put a dummy emptyRDD into my model
- Tried to access sc with model.dummyRDD.context to receive this error:

org.apache.spark.SparkException: RDD transformations and actions can only
be invoked by the driver, not inside of other transformations; for example,
rdd1.map(x => rdd2.values.count() * x) is invalid because the values
transformation and count action cannot be performed inside of the rdd1.map
transformation. For more information, see SPARK-5063.

Just like this user got it here
<https://groups.google.com/forum/#!topic/predictionio-user/h4kIltGIIYE> in
predictionio-user group. Any suggestions?

Here's a more of my predict method:

def predict(model: SomeModel, query: Query): PredictedResult = {

  def predict(model: SomeModel, query: Query): PredictedResult = {


  val appName = sys.env.getOrElse[String]("APP_NAME", ap.appName)

      var previousEvents = try {
        PEventStore.find(
          appName = appName,
          entityType = Some(ap.entityType),
          entityId = Some(query.entityId.getOrElse(""))
        )(model.dummyRDD.context).map(event => {

          Try(new CustomEvent(
            Some(event.event),
            Some(event.entityType),
            Some(event.entityId),
            Some(event.eventTime),
            Some(event.creationTime),
            Some(new Properties(
              *...*
            ))
          ))
        }).filter(_.isSuccess).map(_.get)
      } catch {
        case e: Exception => // fatal because of error, an empty query
          logger.error(s"Error when reading events: ${e}")
          throw e
      }

     ...

}