spark streaming scala example

Analysis of Spark Streaming principlesReceive Execution Process Data StreamingContextDuring instantiation, You need to inputSparkContextAnd then specifyspark matser urlTo connectspark engineTo obtain executor. After instantiation, you must first specify a method for receiving data, as shown in figure val lines = ssc.socketTextStream(localhost, 9999) In this way, text data is received from the socket. In thi

) The exception here is because the Kafka is reading the specified offset log (here is 264245135 to 264251742), because the log is too large, causing the total size of the log to exceed Fetch.message.max.bytesThe Set value (default is 1024*1024), which causes this error. The workaround is to increase the value of fetch.message.max.bytes in the parameters of the Kafka client.For example://kafka configuration file val kafkaparams = map[string, String] (

, StringDecoder](ssc, kafkaParams, topicMap, StorageLevel.MEMORY_AND_DISK_SER).map(_._2)There are still data loss issues after opening WalEven if the Wal is officially set, there will still be data loss, why? Because the task is receiver also forced to terminate when interrupted, will cause data loss, prompted as follows:0: Stopped by driverWARN BlockGenerator: Cannot stop BlockGenerator as its not in the Active state [state = StoppedAll]WARN BatchedWriteAheadLog: BatchedWriteAheadLog Writer que

Mode CREATE temporary TABLE USING OPTIONSAfter Spark1.2, a table that creates an external data source is supported by the DDL syntax for create temporary table USING options.CREATE Temporary TABLE jsontableusing org.apache.spark.sql.jsonOPTIONS ( path '/path/to/data.json ')1. Operation Example:Let's take example down the People.json file to do an example.shengli-mac$ cat/users/shengli/git_repos/spark/exam

From java:openjdk-8ENV hadoop_home/opt/spark/hadoop-2.6.0ENV mesos_native_library/opt/libmesos-0.22.1. soenv sbt_version0.13.8ENV scala_version2.11.7RUNmkdir/opt/Sparkworkdir/opt/spark# Install scalarun cd/root Curl-o scala-$SCALA _version.tgz http://downloads.typesafe.com/scala