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Course Introduction & Hadoop Fundamentals
Introduction
How to unzip .gz files in a new directory in hadoop? (Theory)
How to unzip .gz files in a new directory in hadoop? (Hands On)
Scenario: How to Improve HDFS -put Performance
How does Hadoop Namenode failover process works?
Scenario: HDFS File Listing and Sorting by TimeStamp
How can we initiate a manual failover when automatic failover is configured?
When not use Hadoop?
Is there a simple command for hadoop that can change the name of a file ?
When To Use Hadoop?
Scenario: Concurrent File Rename and Write Behavior in HDFS
HDFS Architecture, Scaling & Hardware Sizing
Can I have multiple files in HDFS use different block sizes?
Scenario: Fixing Native Hadoop Library Warning
As we talk about Hadoop is Highly scalable how well does it Scale?
What platforms and Java versions does Hadoop run on?
What kind of hardware scales best for Hadoop?
Is there an easy way to see the status and health of a cluster?
Scenario: How to Add a New node to a running Hadoop Cluster
Scenario: Optimal Hardware Configuration for Hadoop Clusters
Scenario: Network Bandwidth Requirements between Racks
Scenario: How to Recursively List Files in HDFS
Network Configuration, SSH & Cluster Troubleshooting
How to Troubleshoot “Connection Refused” Errors in Hadoop Cluster
Does Hadoop require SSH?
What does NFS: Cannot create lock on (some dir) mean?
Scenario: How to Merge Multiple HDFS Files into One
Scenario: Can Multiple Clients Append to the same HDFS file?
Scenario: Understanding Hadoop.tmp.dir in Hadoop
Scenario: Where Does HDFS Store Files Locally?
Scenario: Does HDFS Automatically Rebalance Data?
How to Specify Username When Uploading to HDFS from a Remote Machine
Scenario: Understanding HDFS Block Size vs Disk Block Size
Storage Volumes, DataNode Management & Secondary NameNode
What is the purpose of the secondary name-node?
Does Namenode Wait for Full Block Replication in Safe Mode?
How to Configure Multiple Storage Volume in Hadoop Nodes
Scenario: How to Safely Remove Datanode from Hadoop Cluster
Does HDFS Maintain Record Boundaries Between Data Blocks?
Does Wildcard characters work correctly in FsShell?
Hadoop Error: File Could Only Be Replicated to 0 Nodes
Scenario: Does HDFS Consume Full Block Size for Small Files?
What happens when two clients try to write into the same HDFS file?
How to limit Data node's disk usage?
HDFS Commands, Disk Balancing & Data Ingestion
Scenario: Hadoop Namenode Failure - Can HDFS be recovered if FSImage is Lost?
Scenario: Hadoop HA Error
On an individual data node, how do you balance the blocks on the disk?
Scenario: HDFS Missing Blocks Warning
Difference between hadoop fs -put and hadoop fs -copyFromLocal?
Scenario: Why no Hadoop fs -head Command?
How to check HDFS Directory size?
Scenario: Copy files from HDFS to Local File System
On what concept the Hadoop framework works?
What is Hadoop streaming?
Data Replication, Rack Awareness & Cluster Sync
Explain about the process of inter cluster data copying.?
Scenario: HDFS Replication Factor
Differentiate between Structured and Unstructured data?
Explain the difference between NameNode, Backup Node and Checkpoint NameNode?
How can you overwrite the replication factors in HDFS?
What is the process to change the files at arbitrary locations in HDFS?
Explain about the indexing process in HDFS?
What is a rack awareness and on what basis is data stored in a rack?
What happens to a NameNode that has no data?
Scenario: What happens when Name node goes down during job submission?
Execution Modes, InputFormats & Fault Tolerance
Scenario: What happens when jobtracker goes down?
Whenever a client submits a hadoop job who receives it?
What do you understand by edge nodes in Hadoop?
What are real-time industry applications of Hadoop?
What all modes Hadoop can be run in?
Explain the major difference between HDFS block and InputSplit?
What are the most common Input Formats in Hadoop?
What is Speculative Execution in Hadoop?
What is Fault Tolerance?
What is a heartbeat in HDFS?
MapReduce Core Architecture & Small Files Handling
How to keep HDFS cluster balanced?
How to deal with small files in Hadoop?
Scenario: Difference between Hadoop fs and hdfs dfs commands
What type of problems can mapreduce solve?
What is the difference between Hadoop Map Reduce and Google Map Reduce?
How to get the input file name in the mapper in a Hadoop program?
Scenario: Fork/Join vs MapReduce in Hadoop
Scenario: How Hadoop handles records across Block boundaries
Scenario: How to Merge reducer output file in Hadoop MapReduce
Can you set number of map task in Map reduce?
Shuffle, Sort, Partitioners & Custom Configurations
If your Mapreduce Job launches 20 task for 1 job can you limit to 10 task?
Scenario: How to fix Container Memory Limit error in Hadoop YARN
What is Shuffling and Sorting in Hadoop MapReduce?
How do I submit extra content (jars, static files, etc) for Mapreduce job to use
How do I get my MapReduce Java Program to read the Cluster's set configuration?
Scenario: What Happens if One of 50 Hadoop Tasks Fails?
What is OutputCommitter?
What is RecordReader in a Map Reduce?
What is a MapReduce Combiner?
What do you understand by the term Straggler ?
MapReduce Performance Tuning & Job Optimization
What is identity Mapper and identity reducer?
What is the role of a MapReduce partitioner?
When should you use a reducer?
What steps do you follow in order to improve the performace of Mapreduce Job?
What is the purpose of shuffling and sorting phase in the reducer in Map Reduce
Scenario: How to process one entire Input file per Mapper in Hadoop MapReduce
What do you understand by compute and storage nodes?
Is it possible to rename the output file?
What is the default input type in MapReduce?
How is reporting controlled in hadoop?
InputSplits, Record Boundaries & Reducer Phases
Scenario: How do you increase concurrent map and reduce tasks in Hadoop?
How do Map/Reduce InputSplit's handle record boundaries correctly?
Scenario: How to Customize Hadoop output file names
Can we search files using wildcards
What is the difference between Hadoop and RDBMS?
Can reducers communicate with each other?
What is a TaskInstance?
What are the primary phases of a Reducer?
Scenario: Inputsplit#getlocations() in Hadoop
How do you gracefully stop a running job?
Task Slots, Split Size Sizing & Combiner Best Practices
How do I limit Limiting Task Slot Usage
How to increase the number of slots used?
Scenario: When do reduce Tasks start in Hadoop?
What is the process of changing the split size if there is limited storage space
Is it important for Hadoop MapReduce jobs to be written in Java?
What is the relationship between Job and Task in Hadoop?
When is it suggested to use a combiner in a MapReduce job?
Explain the differences between a combiner and reducer.
Where is Mapper output stored?
Is it possible to split 100 lines of input as a single split in MapReduce?
Real-World Architectural & Scenario-Based Interview Questions
List the configuration parameters that have to be specified when running a MRjob
Scenario: How do you chain Multiple MapReduce jobs in Hadoop?
When is it not recommended to use MapReduce paradigm for large scale data?
What is the fundamental difference between a MapReduce Split and a HDFS block?
What happens when a DataNode fails during the write process?
Scenario: How Secondary Sorting works in Hadoop MapReduce
How data is spilt in Hadoop?
Explain about the basic parameters of mapper and reducer function.