This course focuses onSpark, the hottest, most popular and promising technology in the big Data world today. In this course, from shallow to deep, based on a large number of case studies, in-depth analysis and explanation of Spark, and will contain completely from the enterprise real complex business needs to extract the actual case. The course will cover Scala programming,
crossvalidator is very high, however, compared with heuristic manual validation, cross-validation is still a very useful parameter selection method in existence.
Scala:
Import org.apache.spark.ml.Pipeline Import org.apache.spark.ml.classification.LogisticRegression Import Org.apache.spark.ml.evaluation.BinaryClassificationEvaluator import org.apache.spark.ml.feature. {HASHINGTF, tokenizer} import org.apache.spark.ml.linalg.Vector import org.apache.s
copied this Scala version.
Sparkwordcount.scala class implements the spark Chinese word segmentation statistics core function, is in the DT Big Data dream Factory Wang Jialin Teacher's sparkwordcount code based on rewrite.
First, the main functional steps are moved from the companion object's main method to the Sparkwordcount class, and split into multiple methods so that the main method of the companion o
The Java version of the spark Big Data Chinese word Segmentation Statistics program was completed, and after a week of effort, the Scala version of the sparkBig Data Chinese Word segmentation Statistics program also made out, here to share to you want to learn spark friends.The following is the final interface of the program, and the Java version is not very diff
3, hands-on generics in Scalageneric generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scalaimplicit conversion is one of the key points that many people learn about Scala, which i
3, hands on the abstract class in ScalaThe definition of an abstract class requires the use of the abstract keyword:
The above code defines and implements the abstract method, it is important to note that we put the direct running code in the trait subclass of the app, about the inside of the app helps us implement the Main method and manages the code written by the engineer;Here's a look at the use of uninitialized variables in an abstract class:
4, hands-on trait in ScalaTrait
perfect the case34 Regional Sales by day35 Time Window36 de-weight class calculation case, with the calculation of UV as an example37 [Stream Computing project] requirements description and architecture design38 [Stream Computing Project]hbase DAO class development and testing39 [Flow Calculation project]spark and servlet code explained40 [Flow Calculation Project]highcharts code, project runSPARK2 Compreh
The spark kernel is developed by the Scala language, so it is natural to develop spark applications using Scala. If you are unfamiliar with the Scala language, you can read Web tutorials A Scala Tutorial for Java programmers or re
} catch {case e: exception = //do some log} finally { Statement.close () Conn.close ()})}) It is worth noting that:
When we submitted the MySQL operation, not every record was submitted once, but in the form of batch submission, so we need to Conn.setautocommit (false), so as to further improve the efficiency of MySQL.
If we update MySQL with indexed fields, it will cause the update is slow, this situation should try to avoid, if unavoidable, then hard bar (t^t)
Deplo
2.10, because I am through spark-core_${scala.version} is looking for spark dependency package, Some days ago a colleague followed this to build, because the version of the last spark dependent package always fail. Please check your version yourself.
Here are a few small questions to keep in mind:There's going to be Src/main/
This article first describes how to configure the Maven+scala development environment in Eclipse, and then describes how to implement the spark local run. Finally, the spark program written by Scala is successfully run.
At first, my Eclipse+maven environment was well configured.
System: Win7
Eclipse version: Luna rele
To spark it is a computational framework in the spark environment that not only supports single file operations, HDFs files, but also uses spark for hbase operations.Extracted from the enterprise data source HBase. This involves reading
2, Scala simple example
Reference Tutorial: HTTPS://YQ.ALIYUN.COM/TOPIC/69 2.1 Interactive Programming
Spark-shell is spark interactive operating mode, provides interactive programming, side-knocking code side execution, do not need to create program source files, convenient debugging procedures, conducive to rapid le
, implicit and implicit images, and implicit conversions are features of Scala. Scala language because there is an implicit conversion so there is a mistake before you will be able to judge the implicit in the same meaning can be out of the function of the Imperial Army, if any, it will adjust the implicit conversion method to complete this conversion. The Scala
3, hands-on generics in Scala generic generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scala Implicit conversion is one of the ke
] = spark.MappedRDD@2ee9b6e32. RDD has two types of operations: action (return values) and transformations (return a new RDD). Below we start a few actions:
Scala> textFile. count () // Number of items in this RDDres0: Long = 74 scala> textFile. first () // First item in this RDDres1: String = # Spark3. Use the filter in transformations to return the new RDD of a file subset.
5. Apply method and Singleton object in Scala to create a new class: As an additional point, the methods placed in object objects are static methods, as follows: Next look at the use of the Apply method: The above code always when we use "val a = Applytest ()" will cause the call of the Apply method and return the value of the method call, that is, the instantiated object of the applytest. C The lass can also be used by the Apply method, as shown
Discussion on the applicability of Hadoop, Spark, HBase and Redis (full text)
2014-06-15 11:22:03
url:http://datainsight.blog.51cto.com/8987355/1426538
Recently on the web, I saw a discussion about the applicability of Hadoop [1]. Think of this year's big data technology started by the Internet giants to the small and medium internet and traditional industries, it is estimated that many people are consider
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