@Evolving public interface StreamingDataWriterFactory extends java.io.Serializable
StreamingWrite.createStreamingWriterFactory(PhysicalWriteInfo), which is responsible for creating and initializing the actual data writer at executor side.
Note that, the writer factory will be serialized and sent to executors, then the data writer
will be created on executors and do the actual writing. So this interface must be
DataWriter doesn't need to be.
DataWriter<org.apache.spark.sql.catalyst.InternalRow> createWriter(int partitionId, long taskId, long epochId)
If this method fails (by throwing an exception), the corresponding Spark write task would fail and get retried until hitting the maximum retry times.
partitionId- A unique id of the RDD partition that the returned writer will process. Usually Spark processes many RDD partitions at the same time, implementations should use the partition id to distinguish writers for different partitions.
taskId- The task id returned by
TaskContext.taskAttemptId(). Spark may run multiple tasks for the same partition (due to speculation or task failures, for example).
epochId- A monotonically increasing id for streaming queries that are split in to discrete periods of execution.