cascading

问题 I'm working on a cascading program which needs to find not only a word count, but also the total fraction of all words that accounts for. I've had no problem getting as far as the word count itself and also computing the sum of all the counts, into a separate pipe with one field and one tuple. If I can get the total on to each word count tuple, I'll have no problem doing the computation. It's a simple cartesian product... but how do I do that? It seems like it should be a CoGroup with no join

问题 There are notice about what how cascading/scalding optimized map-side evaluation They use so called Partial Aggregation. Is it actually better approach then Combiners? Are there any performance comparison on some common hadoop tasks(word count for example)? If so wether hadoop will support this in future? 回答1: In practice, there are more benefits from partial aggregation than from use of combiners. The cases where combiners are useful are limited. Also, combiners optimize the amount of

问题 I have two files with one common field, based on that field value i need to get the second file values. How do i add the where Condition here? Is there any other PIPE available for NOT IN use? File1: tcno,date,amt 1234,3/10/2016,1000 1234,3/11/2016,400 23456,2/10/2016,1500 File2: cno,fname,lname,city,phone,mail 1234,first,last,city,1234556,123@123.com Sample Code: Pipe pipe1 = new Pipe("custPipe"); Pipe pipe2 = new Pipe("tscnPipe"); Fields cJoinField = new Fields("cno"); Fields tJoinField =

问题 I know that I can submit a Cascading job by packaging it into a JAR, as detailed in the Cascading user guide. That job will then run on my cluster if I manually submit it using hadoop jar CLI command. However, in the original Hadoop 1 Cascading version, it was possible to submit a job to the cluster by setting certain properties on the Hadoop JobConf . Setting fs.defaultFS and mapred.job.tracker caused the local Hadoop library to automatically attempt to submit the job to the Hadoop1

问题 I'm new to stackoverflow as well as to jquery/javascript. I've been searching all day for different ways to add cascading drop down lists to my current project and have yet to find a way that has worked for me. Most of my finding have been from out of date and based upon MVC 2 to webforms to older technologies. I did find a few tutorials and posts based upon MVC 3/4 that have helped but I'm still about to chunk my mouse at my computer screen. Some links that I've looked at for help are: Radu

问题 Lets see what we have. First file [Interface Class]: list arrayList list linkedList Second file[Class1 amount]: arrayList 120 linkedList 4 I would like to join this two files by key[Class] and get count per each Interface: list arraylist 120 list linkedlist 4 Code: public class Main { public static void main( String[] args ) { String docPath = args[ 0 ]; String wcPath = args[ 1 ]; String doc2Path = args[ 2 ]; Properties properties = new Properties(); AppProps.setApplicationJarClass(

问题 My data format uses \0 instead of new line. So default hadoop textLine reader dosn't work. How can I configure it to read lines separated by special character? If it is impossible to configure LineReader, Maybe it is possible to apply specic stream processor(tr "\0" "\n") not sure how to do this. 回答1: You can write your own InputFormat class that splits data on \0 instead of \n . For a walkthrough on how to do that, check here: http://developer.yahoo.com/hadoop/tutorial/module5.html

问题 I'm trying to write a Casacading(v1.2) casade (http://docs.cascading.org/cascading/1.2/userguide/htmlsingle/#N20844) consisting of two flows: 1) The first flow outputs url s to a db table, (in which they are automatically assigned id's via an auto-incrementing id value). This flow also outputs pairs of urls into a SequenceFile with field names " urlTo ", " urlFrom ". 2) The second flow reads from both these sources and tries to do a CoGroup on " urlTo " (from the SequenceFile) and " url "

问题 So people have been having problems compressing the output of Scalding Jobs including myself. After googling I get the odd hiff of an answer in a some obscure forum somewhere but nothing suitable for peoples copy and paste needs. I would like an output like Tsv , but writes compressed output. 回答1: Anyway after much faffification I managed to write a TsvCompressed output which seems to do the job (you still need to set the hadoop job system configuration properties, i.e. set compress to true,

问题 am migrating from swing to javafx. Can anyone help with a link/code snippet on how to cascade combobox(es) based on parent-child selection in javafxe.g. country-state, branch-department-unit. 回答1: Use this code:for basic drop down example package comboboxexamplestackoverflow; import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx