Questions tagged [cascading]

Cascading is a Query API, Query Planner, and Process Scheduler used for defining and executing complex, scale-free, and fault tolerant data processing workflows on a Hadoop cluster.

Cascading is a Query API, Query Planner, and Process Scheduler used for defining and executing complex, scale-free, and fault tolerant data processing workflows on a Hadoop cluster.

Cascading is a thin Java library that sits on top of Hadoop's MapReduce layer and is executed from the command line like any other Hadoop application. It is not a new text based query syntax (like Pig) or another complex system that must be installed on a cluster and maintained (like Hive). Though Cascading is both complimentary to and is a valid alternative to either application.

Cascading lets the developer quickly assemble complex distributed data-processing applications without having to "think" in MapReduce. And to efficiently schedule them based on their dependencies. Obviously simple data processing applications are supported as well, as complex applications tend to start simple.

Cascading is Open Source and dual licensed under the GPL and OEM/Commercial Licenses. OEM/Commercial Licenses and Developer Support can be obtained through Concurrent, Inc.

Cascading has a strong community of users and contributors, see our Cascading modules page for related projects and extensions.

Cascading, extensions, and related libraries are also hosted in the Conjars maven repository maintained by Concurrent, Inc. The repository is open to the public.

Cascading application-stack overview: enter image description here

Links:

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cascading : How to read or write multicharactor word?

If 'Each' read GBK String from file and Write GBK String to file, how can i do? How to define it? Fields namesFields = new Fields("zid", "vid", "title", "number"); sourcePipe = new Each(sourcePipe, new Fields("line"), new Parse(namesFields),…
cdhit
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cartesian product in cascading

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…
Russell Mull
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Cascade Hadoop file loading - method to deal with records crossing a newline?

I'm working with Hadoop to process some files distributed across a cluster of JVM instances. I'm using the Cascading library to interface to Hadoop. I want to parse a text file where the records cross newlines and are terminated by a period:…
hawkeye
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got error when running Cascading code on CDH3 - token can't be found in cache

Can someone help me out with following error when running a Cascading code? The error happens when a CoGroup() is used to join two data streams. These two data streams are fine if they are separately output into a sink. I'm using Cascading 2.0 &…
wagnerj
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AJAX Toolkit cascading dropdown list database - CS ok, but VB fail

Cascading dropdown list is ok with CS but the same site in VB doesn't work. In VB the last dropdown list looses it's value when postback, it takes the value of the previous dropdown list. The two sites are in the following link sites. Both sites…
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Load balancing Cascading JDBCTap for MySQL

I am considering writing a Cascading application that issues SELECT statements to MYSQL databases where each query can return millions of rows. Each database exists on N slaves and one master, as shown here:…
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CSS Cascading takes over inheritance, how to solve this?

We have run into a wall trying to figure out why CSS inheritance does not work as expected. To describe the problem... I have a reusable CSS that defines various background colors and we switch backgrounds and foregrounds of various sections of the…
smallworld
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Access Cascaded JSON in javascript

If I have the following JSON object, how can I access the survey.id (e.g 1) using JavaScript? I'm using Backbone / json.stringify / object.parse [{ "class": "org.example.UserBooking", "id": 1, "booking": { "class": "Booking", …
Tyler Evans
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How to track lots of statistics with map-reduce cascading?

I have a series map-reduce jobs to process user data (implemented using the Cascading framework), and I would like to track lots of fine-grained statistics (I can have between 100 and 1000 users and 20 statistics per user, so, possibly between 5000…
register
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Changing Schemas with Hadoop Cascading

I'm trying to figure out how to use cascading against an archive of data whose schema is additive over time. Why I mean by additive is that it will start out with 3 columns, for example. Then in the next release it might have 5 columns. These…
Virmundi
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Schema validation

H, I am looking for any example for schema validation for data. Is it possible to do using cascading or scalding. For example Name:String , Age:Int We say our data should confirm to above schema then we can validate if data really is of that…
user2230605
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display the current cascading drop data in sharepoint 2013 using knockout js

i want to create cascading drop down lookup list in sharepoint 2013. i want to take the data ,whatever i currently entered that data will be displayusing knockout js in sharepoint 2013. so please give me some solution. Thanks
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PHP array_filtered acces object

I'm trying to filter array from DB and I've got this postman response: { "1": { "id": "3", "key": "emails_html_body_start", "value": "value" }} How I can access to id, key, value? My code here: $start = array_filter($array, function…
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Visual Basic ACCDB File Read for Cascading Combo Box

So I've got an access database with three columns in: Manufacture, Fixture and Mode I'm using the code below to create cascading combo boxes in my form. Imports System.Data.OleDb Public Class Add_Fixtures Dim con As New OleDbConnection Dim…
Harry Bilney
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