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Diffstat (limited to 'python/pyspark/streaming/mqtt.py')
-rw-r--r-- | python/pyspark/streaming/mqtt.py | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/python/pyspark/streaming/mqtt.py b/python/pyspark/streaming/mqtt.py new file mode 100644 index 0000000000..f06598971c --- /dev/null +++ b/python/pyspark/streaming/mqtt.py @@ -0,0 +1,72 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +from py4j.java_gateway import Py4JJavaError + +from pyspark.storagelevel import StorageLevel +from pyspark.serializers import UTF8Deserializer +from pyspark.streaming import DStream + +__all__ = ['MQTTUtils'] + + +class MQTTUtils(object): + + @staticmethod + def createStream(ssc, brokerUrl, topic, + storageLevel=StorageLevel.MEMORY_AND_DISK_SER_2): + """ + Create an input stream that pulls messages from a Mqtt Broker. + :param ssc: StreamingContext object + :param brokerUrl: Url of remote mqtt publisher + :param topic: topic name to subscribe to + :param storageLevel: RDD storage level. + :return: A DStream object + """ + jlevel = ssc._sc._getJavaStorageLevel(storageLevel) + + try: + helperClass = ssc._jvm.java.lang.Thread.currentThread().getContextClassLoader() \ + .loadClass("org.apache.spark.streaming.mqtt.MQTTUtilsPythonHelper") + helper = helperClass.newInstance() + jstream = helper.createStream(ssc._jssc, brokerUrl, topic, jlevel) + except Py4JJavaError as e: + if 'ClassNotFoundException' in str(e.java_exception): + MQTTUtils._printErrorMsg(ssc.sparkContext) + raise e + + return DStream(jstream, ssc, UTF8Deserializer()) + + @staticmethod + def _printErrorMsg(sc): + print(""" +________________________________________________________________________________________________ + + Spark Streaming's MQTT libraries not found in class path. Try one of the following. + + 1. Include the MQTT library and its dependencies with in the + spark-submit command as + + $ bin/spark-submit --packages org.apache.spark:spark-streaming-mqtt:%s ... + + 2. Download the JAR of the artifact from Maven Central http://search.maven.org/, + Group Id = org.apache.spark, Artifact Id = spark-streaming-mqtt-assembly, Version = %s. + Then, include the jar in the spark-submit command as + + $ bin/spark-submit --jars <spark-streaming-mqtt-assembly.jar> ... +________________________________________________________________________________________________ +""" % (sc.version, sc.version)) |