MapReduce | Querying IMDB dataset using MapReduce and Hadoop framework

Note: this is more a basic programming question and nothing about the Hadoop or Map/Reduce methods of "big data processing".

Let's take a sequence (1 2 3 4 5):

To map it to some function, let's say square, I can do something like:

I am confused about the apache-dolphinscheduler's queue, as in user-guide, the queue is used for spark、mapreduce. But I want to use python code product seeds to queue and another python code in workers pull seeds from queue and run tasks. Can you tell me whether dolphinscheduler can handle it or I must use another tools, such as Redis? Thanks.

I've been trying to implement the TfIdf algorithm using MapReduce in Hadoop. My TFIDF takes place in 4 steps (I call them MR1, MR2, MR3, MR4). Here are my input/outputs:

MR1: (offset, line) ==(Map)==> (word|file, 1) ==(Reduce)==> (word|file, n)

MR2: (word|file, n) ==(Map)==> (file, word|n) ==(Reduce)==> (word|file, n|N)

MR3: (word|file, n|N) ==(Map)==> (word, file|n|N|1) ==(Reduce)==> (word|file, n|N|M)

MR4: (word|file, n|N|M) ==(Map)==> (word|file, n/N log D/M)

Where n = number of (word, file) distinct pairs, N = number of words in each file, M = number of documents where each word appear, D = number of documents.

As of the MR1 phase, I'm getting the correct output, for example: hello|hdfs://..... 2

For the MR2 phase, I expect: hello|hdfs://....... 2|192 but I'm getting 2|hello|hdfs://...... 192|192

I'm pretty sure my code is correct, every time I try to add a string to my "value" in the reduce phase to see what's going on, the same string gets "teleported" in the key part.

Example: gg|word|hdfs://.... gg|192

Here is my MR1 code:

In the hbase-1.4.10, I have enabled replication for all tables and configured the peer_id. the list_peers provide the below result:

Details:

• Apache CouchDB v. 3.1.1
• about 5 GB of twitter data have been dumped in partitions

Map reduce function that I have written:

I built the Apache Oozie 5.2.1 from the source code in my MacOS and currently having trouble running it. The ClassNotFoundException indicates a missing class org.apache.hadoop.conf.Configuration but it is available in both libext/ and the Hadoop file system.

I followed the 1st approach given here to copy Hadoop libraries to Oozie binary distro. https://oozie.apache.org/docs/5.2.1/DG_QuickStart.html

I downloaded Hadoop 2.6.0 distro and copied all the jars to libext before running Oozie in addition to other configs, etc as specified in the following blog.

https://www.trytechstuff.com/how-to-setup-apache-hadoop-2-6-0-version-single-node-on-ubuntu-mac/

This is how I installed Hadoop in MacOS. Hadoop 2.6.0 is working fine. http://zhongyaonan.com/hadoop-tutorial/setting-up-hadoop-2-6-on-mac-osx-yosemite.html

This looks pretty basic issue but could not find why the jar/class in libext is not loaded.

• OS: MacOS 10.14.6 (Mojave)
• JAVA: 1.8.0_191
• Hadoop: 2.6.0 (running in the Mac)

In order to use infix notation, I have the following example of scala code.

I have some problems with a map reduce I tried to do in MongoDB. A function I defined seems to not be visible in the reduce function. This is my code:

i am getting this error when i do spark submit. java.lang.IllegalArgumentException: Can not create a Path from an empty string i am using spark version 2.4.7 hadoop version 3.3.0 intellji ide jdk 8 first i was getting class not found error which i solved now i am getting this error Is it because of the dataset or something else. https://www.kaggle.com/datasnaek/youtube-new?select=INvideos.csv link to dataset

error: