Questions tagged [apache-hadoop]
Hadoop is an Apache open-source project that provides software for reliable and scalable distributed computing. The project itself includes a variety of other complementary additions.
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questions
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How to run unmodified Python program on GPU servers with scheduled GPUs?
Say I have one server with 10 GPUs. I have a python program which detects available GPU and use all of them.
I have a couple of users who will run python (Machine learning or data mining) programs and ...
3
votes
1answer
51 views
What is the main difference between Hadoop and Spark? [closed]
I recently read the following about Hadoop vs. Spark:
Insist upon in-memory columnar data querying. This was the killer-feature that let Apache Spark run in seconds the queries that would take Hadoop ...
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0answers
62 views
Unexpected arguments error appearing on the command line when running mapreduce job (MRjob) using python
I am fairly new to this process. I am trying to run a simple map-reduce job using python 3.8 with a csv on a local Hadoop cluster (Hadoop version 3.2.1). I am currently running it on Windows 10 (64-...
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1answer
31 views
Hive / Impala best practice code structuring
Coming from a DWH-background I am used to putting subqueries almost everywhere in my queries. On a Hadoop project (with Hive version 1.1.0 on Cloudera), I noticed we can forego subqueries in some ...
0
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1answer
16 views
What are common problems around HADOOP storage?
I've been asked to lead a program to understand why our Hadoop storage is constantly near capacity. What questions should I ask?
Data age,
Data size?
Housekeeping schedule?
How do we identify the ...
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0answers
592 views
cannot access hive from spark [closed]
I am trying to install a hadoop + spark + hive cluster.
I am using hadoop 3.1.2, spark 2.4.5 (scala 2.11 prebuilt with user-provided hadoop) and hive 2.3.3 (also tried 3.1.2 with the exact same ...
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0answers
22 views
Loading file into and out of HDFS via system call/cmd line vs using libhdfs
I am trying to implement a simple C/C++ program for the HDFS file system like word count, it takes a file from the input path puts it into HDFS (where it gets split), processed my map-reduce function ...
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0answers
10 views
Processing XML via StreamXmlRecordReader and Pig in parallel
I'm trying to process a single large XML file with many records and then parse each record in parallel using AWS EMR.
...
3
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1answer
202 views
BERT in production
I've created a BERT model. What are the ways to do the deployment of this model? Is it possible to use it with Spark, Hadoop or Docker?
2
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1answer
1k views
Are parquet files compressed? [closed]
Parquet File Format Hadoop. Parquet, an open-source file format for Hadoop. Parquet stores nested data structures in a flat columnar format. Compared to a traditional approach where data is stored in ...
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0answers
28 views
How to push tasks to remote Hadoop/Spark cluster
I have access to a Hadoop cluster provided by a third party. Currently, I use Spark on this cluster by logging in to a Zeppelin ...
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0answers
73 views
How to create tensors in spark?
I have the following data stored in HDFS: each row has three columns, id, date, item, which means a person with a particular id bought a particular item on a particular date. The dataset has billions ...
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0answers
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Mapreduce jobs not working in hive
I was trying to execute a hive query:
select name, count(*)
from amazon
where review != NULL
group by name ;
Number of reduce tasks not specified. Estimated ...
0
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2answers
333 views
What is the MapReduce application master?
From Hadoop The Definitive Guide
The whole process is illustrated in Figure 7-1. At the highest level,
there are five independent entities:
• The client, which submits the MapReduce ...
0
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1answer
16 views
what does “blocks” mean in the context of HDFS ecosystem? is it the same concept in the context of a single hard disk drive?
According to Hortonworks
HDFS has demonstrated production scalability of up to 200 PB of
storage and a single cluster of 4500 servers, supporting close to a
billion files and blocks.
what does ...
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0answers
396 views
Datanode not starting on Slave Nodes for Apache Hadoop+Spark Setup
I know similar questions have been asked and I already looked through a lot of them to figure out what the issue might be, but to no avail.
I am a College student currently working on a Big Data ...
0
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1answer
45 views
SAP HANA or Hadoop? [closed]
this is a question regarding a career choice. I am a fresher and I recently joined an MNC in Data Engineering team. There I was offered training in either Hadoop or SAP HANA. I am in doubt as to which ...
4
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1answer
356 views
Is there any point in learning Hadoop in 2018?
I'm a data analyst/scientist working mostly with the Python open source stack i.e. Pandas, scikit-learn, matplotlib, seaborn etc. I want to expand my toolbox and learn a distributed computing ...
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Accumulators in Spark (PySpark) without global variables?
BACKGROUND
Consider the following textbook example which uses accumulators to add vectors.
...
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1answer
4k views
PySpark: java.io.EOFException
System:
1 name node, 4 cores, 16 GB RAM
1 master node, 4 cores, 16 GB RAM
6 data nodes, 4 cores, 16 GB RAM each
6 worker nodes, 4 cores, 16 GB RAM each
around 5 Terabytes of storage space
The data ...
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0answers
20 views
Remote sensing image data storage in hadoop hdfs [closed]
I am new to hadoop environment. anyone kindly please help me how to store the remote sensing image data in hadoop hdfs? thanks in advance
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0answers
83 views
Unable to open application master UI in spark1.6.1 in cluster mode
Hadoop cluster has 8 nodes with high availability of resource manager. Active ResourceManager is in node 3. and Standby ResourceManager in node 2.
when i submit the application in cluster mode. the ...
3
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0answers
448 views
Communication between name node, data node and client in hadoop by analysing Packet Capturing [closed]
if I say that in hadoop cluster system... A client has 10GB data to send to name node. After analysing the "packet capturing" actually the name node doesn't divide the data for data node, ...
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0answers
104 views
Change log level of yarn?
I'd like to change the log level of yarn. For example, when I run yarn node -list, I see a line that says ...
0
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2answers
168 views
Are Hadoop and Python SciPy used for the same? [closed]
Right now
I've been doing a bit of research because I'm quite new to Big Data world. Among several other tools or frameworks, I've read about Apache Hadoop and Python for data analysis.
Specifically,...
2
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1answer
52 views
does storing file in hdfs parallelize it for Spark?
For Spark's RDD operations, data must be in shape of RDD or be parallelized using:
ParallelizedData = sc.parallelize(data)
My question is that if I store data in ...
2
votes
1answer
341 views
Best practice for developing using Spark [closed]
I am looking for any tips and best practice on how to develop applications using Spark. I currently have access to a cluster, with data as well as a version of Spark 2.1.0 on an edge node and IntelliJ ...
5
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1answer
1k views
Saving Large Spark ML Pipeline to HDFS
I'm having trouble saving a large (relative to spark.rpc.message.maxSize) Spark ML pipeline to HDFS. Specifically, when I try to save the model to HDFS, it gives me an error related to spark's maximum ...
0
votes
1answer
56 views
Which one of these tasks will benefit the most from SPARK?
My company processes Data (I am only an intern). We primarily use Hadoop. We're starting to deploy spark in production. Currently we have have two jobs, we will choose just one to begin with spark. ...
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0answers
96 views
Tasks of a Yarn Process in Hadoop
I am new to big data and Apache Hadoop YARN. This picture show how Yarn runs applications:
A client requests a Yarn Application. So, in a certain datanode a Container is created and the process is ...
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0answers
31 views
Hdfs Data Balance on Cluster
Im new to Big Data, so please just dont blast me.
Can you explain me why HDFS works
best when the file blocks are evenly spread across the cluster ?
1
vote
0answers
293 views
Hadoop - checksum while reading file from client [closed]
In hadoop , if i want to read a file from client , the class DFSInputStream enters in action.
About this, my textbook says
The DFSInputStream also verifies checksums for the data transferred to it ...
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0answers
345 views
Custom Writable Serialization in Hadoop [closed]
I have some questions about Custom Writable objects in Hadoop. First of all, the private instance variables of the Writable object have to be Writable?
How does Hadoop handle ...
2
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1answer
20 views
Yarn service parameter for pseudodistributed [closed]
I'm trying to set up Hadoop in the pseudodistributed form. So I edited the suggested xml files. In the file yarn-site.xml, I had to insert:
...
1
vote
1answer
45 views
Hadoop and input informations divided in splits [closed]
Hadoop divides the input to a MapReduce job into fixed-size pieces
called input splits, or just splits. Hadoop creates one map task for
each split, which runs the user-defined map function for ...
2
votes
0answers
71 views
Why does my master node get heap memory full for inbuilt SVD API in Apache Spark during calculation of inverse of a square matrix?
I am using a three node system:
Master node: $64$ GB RAM
2 slave node: $32$ GB RAM
I am calculating the inverse of a square matrix using inbuilt Apache Spark function SVD. When I called SVD function ...
0
votes
1answer
112 views
Install Spark and Hadoop in the same machine [closed]
I'm trying to install Spark Apache and Hadoop in the same machine. Spark will be used to process data, and HDFS from Hadoop will be used to store data. I first started by installing spark and it ...
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0answers
286 views
Hadoop Cluster Capacity Planning [closed]
I was doing some digging to get some deeper understanding on the Capacity Planning done for setting up a Hadoop Cluster.
I have a daily ~100 GB of data generated and would like to find how a Capacity ...
3
votes
0answers
221 views
How to setup a home-laptop cluster to 'practice' elasticsearch, hadoop, mesos and spark [closed]
I'd like to have elasticsearch, hadoop, mesos and spark on my home laptop (it's an 8GB with an intel i7 CPU) for practicing the setup of such frameworks and eventually to test their functions.
I'm ...
2
votes
2answers
640 views
Why has Hadoop failed to become popular?
Apache Hadoop was once considered one of the tools you should have as a Data Scientist. Around 2012 to 2014, it gained the popularity steeply among Data Scientists, and seemed to be considered one of ...
2
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0answers
76 views
Are jobs the only way out for data scientists? [closed]
I have reached this point in my data sceince journey that I am left wondering if jobs are the only way out for me...
I am highly skilled in Hadoop, Machine Learning and now getting into Deep Learning ...
1
vote
1answer
117 views
what ETL technique should i use for text documents using Hadoop?
I have a school Big Data project where basically the teacher is going to give us a large amount of text documents (from the Gutenberg project data set ) and he want us to give as output the document ...
1
vote
2answers
367 views
Can R + Hadoop overcome R's memory constraints in any case?
I am an R user and I am interested in learning/understanding how Hadoop actually works. For this I previously read about Hadoop but was not able to find a satisfactory answer for my question.
Can R + ...
3
votes
1answer
230 views
Deploying models on bigdata platforms like Hadoop and Spark
Where exactly bigdata platforms fit in to a data science/ machine learning projects ?
Say I have a large dataset for a binary classification problem - cats and dogs.
Now I need to create a model for ...
2
votes
1answer
1k views
Ingestion of periodic REST API Calls into Hadoop [closed]
We are planning to use REST API calls to ingest data from an endpoint and store the data to HDFS. The REST calls are done in a periodic fashion (daily or maybe hourly).
I've already done Twitter ...
2
votes
1answer
207 views
K-means clustering on big data stored on multiple nodes on HDFS
I have a very basic question about how the k-means clustering algorithm works when the data is stored in HDFS.
Does the training take place on the subset of data on each node for a fixed value of K( ...
2
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2answers
111 views
How many people can use a single Hadoop cluster at one time?
I would like to know how many people can use a single Hadoop cluster at one time? I am asking because I need to figure out whether or not a single 5 or 10 node cluster would be sufficient to host a ...
2
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1answer
332 views
Mahout Spark shell not working
I installed Hadoop, Mahout and Spark. I am able to see the Hadoop and Spark MasterWebUI. Moreover, I can also run the following command,
...
2
votes
2answers
5k views
spark item similarity recommendation
I would like to build an recommendation engine using spark's Mlib itemsimilarity as mentioned here LINK
But it seems spark do not have this algorithm any more and ...
1
vote
1answer
179 views
How to Scaling Out Artifical Neural Networks?
I have started to study ANNs with Tensorflow and Keras. Now I want to find a solution to use ANNs over Hadoop. I have learnt that Spark 2.0 does have a Multilayer Perceptron Classifier, but as far as ...
