今天有哥们问到怎样对Spark进行单元測试.如今将Sbt的測试方法写出来,例如以下:     对Spark的test case进行測试的时候能够用sbt的test命令:     一.測试所有test case      sbt/sbt test     二.測试单个test case      sbt/sbt "test-only *DriverSuite*"  以下举个样例: 这个Test Case是位于$SPARK_HOME/core/src/test/scala/org/…

1.resilient distributed dataset (RDD) The core programming abstraction in Spark, consisting of a fault-tolerant collection of elements that can be operated on in parallel. 2.partition A subset of the elements in an RDD. Partitions define the unit of…

前两篇文章写了Shuffle Read的一些实现细节.但是要想彻底理清楚这里边的实现逻辑,还是需要更多篇幅的:本篇开始,将按照Job的执行顺序,来讲解Shuffle.即,结果数据(ShuffleMapTask的结果和ResultTask的结果)是如何产生的:结果是如何处理的:结果是如何读取的. 在Worker上接收Task执行命令的是org.apache.spark.executor.CoarseGrainedExecutorBackend.它在接收到LaunchTask的命令后,通过在Driv…

What’s New, What’s Changed and How to get Started. Are you ready for Apache Spark 2.0? If you are just getting started with Apache Spark, the 2.0 release is the one to start with as the APIs have just gone through a major overhaul to improve ease-of-…

Explore the configuration changes that Cigna’s Big Data Analytics team has made to optimize the performance of its real-time architecture. Real-time stream processing with Apache Kafka as a backbone provides many benefits. For example, this architect…

The versatility of Apache Spark’s API for both batch/ETL and streaming workloads brings the promise of lambda architecture to the real world. Few things help you concentrate like a last-minute change to a major project. One time, after working with a…

PMML是一种通用的配置文件,只要遵循标准的配置文件,就可以在Spark中训练机器学习模型,然后再web接口端去使用.目前应用最广的就是基于Jpmml来加载模型在javaweb中应用,这样就可以实现跨平台的机器学习应用了. 训练模型 首先在spark MLlib中使用mllib包下的逻辑回归训练模型: import org.apache.spark.mllib.classification.{LogisticRegressionModel, LogisticRegressionWithLBFGS…

参考http://spark.apache.org/docs/latest/configuration.html Spark提供三个位置来配置系统: Spark属性控制大多数应用程序参数,可以使用SparkConf对象或通过Java系统属性进行设置. 可以使用环境变量通过conf/spark-env.sh每个节点上的脚本来设置每台机器的设置,例如IP地址. 日志记录可以通过配置log4j.properties. Spark属性控制大多数应用程序设置,并为每个应用程序单独配置.这些属性可以直接在一…

❤Limitations of DStream API Batch Time Constraint application级别的设置. 不支持EventTime event time 比process time更重要 Weak support for Dataset/Dataframe No custom triggers 比如session的处理,当session跨越长时间,窗口处理也无法满足. NO Update sematic new event可能会update之前已经处理过的state…

应用属性 属性名 缺省值 意义 spark.app.name (none) The name of your application. This will appear in the UI and in log data. spark.master (none) The cluster manager to connect to. See the list ofallowed master URL’s. spark.executor.memory 512m Amount of memory to…