h2o spark

Introduction to spark Core conceptsA spark application initiates various concurrent operations on the cluster by the drive program, and a drive program typically contains multiple executor nodes, and the drive program accesses the SAPRK through a Saprkcontext object. The Rdd (Elastic distributed DataSet)----A distributed collection of elements, and the RDD supports two operations: conversion operations, act

1. Code Writingif (args.length! = 3) {println ("Usage is org.test.WordCount Return}Val sc = new Sparkcontext (args (0), "WordCount",System.getenv ("Spark_home"), Seq (System.getenv ("Spark_test_jar")))Val textfile = Sc.textfile (args (1))Val result = Textfile.flatmap (line = Line.split ("\\s+")). Map (Word (Word, 1)). Reducebykey (_ + _)Result.saveastextfile (args (2))2. Export jar package, here I named Wordcount.jar3. OperationBin/spark-submit--maste

:31)At Com.esotericsoftware.kryo.Kryo.readObject (kryo.java:711)At Com.esotericsoftware.kryo.serializers.ObjectField.read (objectfield.java:125)... More16/05/24 09:42:53 ERROR sparksqldriver:failed in [selectDt.d_year, item.i_brand_id brand_id, Item.i_brand Brand, SUM (ss_ext_sales_price) Sum_aggFrom Date_dim DT, Store_sales, itemwhere Dt.d_date_sk = Store_sales.ss_sold_date_skand Store_sales.ss_item_sk = Item.i_item_skand item.i_manufact_id = 436and dt.d_moy=12GROUP BY Dt.d_year, Item.i_brand,

Transferred from: http://www.cnblogs.com/hseagle/p/3664933.htmlWedgeSource reading is a very easy thing, but also a very difficult thing. The easy is that the code is there, and you can see it as soon as you open it. The hard part is to understand the reason why the author should have designed this in the first place, and what is the main problem to solve at the beginning of the design.It's a good idea to read the spark paper from Matei Zaharia, befor

It is believed that many people will encounter Task not serializable when they start using spark, most of which are caused by calling an object that cannot be serialized in the RDD operator. Why must the objects in the incoming operator be serialized? This is going to start with spark itself, Spark is a distributed computing framework, the RDD (resilient distribu

Use Scala+intellij IDEA+SBT to build a development environmentTipsFrequently encountered problems in building development environment:1. Network problems, resulting in SBT plugin download failure, workaround, find a good network environment,or download the jar in advance from the network I provided (link: http://pan.baidu.com/s/1qWFSTze password: LSZC)Download the. Ivy2 compressed file, unzip it, and put it in your user directory.2. Version matching issue, version mismatch will encounter a varie

Spark Source Learning--in the Linux environment with idea to see Spark source This article mainly solves the problem1.Spark under the Linux experimental environment to build A, spark source reading environment preparation This paper introduces the various configuration methods under CentOS. Here are a list of the comp

　　Originally this article is prepared for 5.15 more, but the last week has been busy visa and work, no time to postpone, now finally have time to write learning Spark last part of the content.第10-11 is mainly about spark streaming and Mllib. We know that Spark is doing a good job of working with data offline, so how does it behave on real-time data? In actual pro

For more than 90% of people who want to learn spark, how to build a spark cluster is one of the greatest difficulties. To solve all the difficulties in building a spark cluster, jia Lin divides the spark cluster construction into four steps, starting from scratch, without any pre-knowledge, covering every detail of the

To run an app on the spark cluster, simply pass through the master's Spark://ip:port link to the Sparkcontext constructorRun the Interactive Spark command on the cluster and run the following command:Master=spark://ip:port./spark-shellNote that if you run the

This time we start Spark-shell by specifying the Executor-memory parameter:The boot was successful.On the command line we have specified that the memory of executor on each machine Spark-shell run take up is 1g in size, and after successful launch see Web page:To read files from HDFs:The Mappedrdd returned in the command line, using todebugstring, can view its lineage relationship:You can see that Mappedrdd

1-Questions raised 2-Linear regression 3-Theoretical derivation 4-python/spark implementation1 #-*-coding:utf-8-*-2 fromPysparkImportSparkcontext3 4 5theta =[0, 0]6Alpha = 0.0017 8sc = Sparkcontext ('Local')9 Ten deffunc_theta_x (x): One returnSUM ([i * j forI, JinchZip (theta, X)]) A - defCost (x): -thx =func_theta_x (x) the returnThx-x[-1] - - defPartial_theta (x): -DIF =Cost (x) + return[DIF * I forIinchX[:-1]] - +

The output from the WordCount in a previous article shows that the results are unsorted and how do you sort the output of spark?The result of Reducebykey is Key,value position permutation (number, character), then the number is sorted, and then the key,value position is replaced by the sorted result, and finally the result is stored in HDFsWe can find out that we have successfully sorted out the results!Spark