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streamingKafka2Cassandra.py
52 lines (43 loc) · 1.74 KB
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streamingKafka2Cassandra.py
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from pyspark.sql import SparkSession
from pyspark.sql.types import StructType,StructField,FloatType,IntegerType
from pyspark.sql.functions import from_json,col
odometrySchema = StructType([
StructField("id",IntegerType(),False),
StructField("posex",FloatType(),False),
StructField("posey",FloatType(),False),
StructField("posez",FloatType(),False),
StructField("orientx",FloatType(),False),
StructField("orienty",FloatType(),False),
StructField("orientz",FloatType(),False),
StructField("orientw",FloatType(),False)
])
# .config("spark.jars.packages","com.datastax.spark:spark-cassandra-connector_2.12:3.0.0")\
spark = SparkSession \
.builder \
.appName("SSKafka") \
.config("spark.jars.packages","org.apache.spark:spark-sql-kafka-0-10_2.12:3.2.0,com.datastax.spark:spark-cassandra-connector_2.12:3.0.0") \
.getOrCreate()
spark.sparkContext.setLogLevel("ERROR")
df = spark \
.readStream \
.format("kafka") \
.option("kafka.bootstrap.servers", "localhost:9092") \
.option("subscribe", "odometry") \
.option("delimeter",",") \
.option("startingOffsets", "latest") \
.load()
df.printSchema()
df1 = df.selectExpr("CAST(value AS STRING)").select(from_json(col("value"),odometrySchema).alias("data")).select("data.*")
df1.printSchema()
def writeToCassandra(writeDF, epochId):
writeDF.write \
.format("org.apache.spark.sql.cassandra")\
.mode('append')\
.options(table="odometry", keyspace="ros")\
.save()
df1.writeStream \
.option("spark.cassandra.connection.host","localhost:9042")\
.foreachBatch(writeToCassandra) \
.outputMode("update") \
.start()\
.awaitTermination()