RDBMS vs Hadoop?
| Name | RDBMS | Hadoop |
| Data volume | RDBMS cannot store and process a large amount of data | Hadoop works better for large amounts of data. It can easily store and process a large amount of data compared to RDBMS. |
| Throughput | RDBMS fails to achieve a high Throughput | Hadoop achieves high Throughput |
| Data variety | Schema of the data is known in RDBMS and it always depends on the structured data. | It stores any kind of data. Whether it could be structured, unstructured, or semi-structured. |
| Data processing | RDBMS supports OLTP(Online Transactional Processing) | Hadoop supports OLAP(Online Analytical Processing) |
| Read/Write Speed | Reads are fast in RDBMS because the schema of the data is already known. | Writes are fast in Hadoop because no schema validation happens during HDFS write. |
| Schema on reading Vs Write | RDBMS follows schema on write policy | Hadoop follows the schema on reading policy |
| Cost | RDBMS is a licensed software | Hadoop is a free and open-source framework |
What is Hadoop and list its components?
Hadoop is an open-source framework used for storing large data sets and runs applications across clusters of commodity hardware.
It offers extensive storage for any type of data and can handle endless parallel tasks.
Core components of Hadoop:
- Storage unit– HDFS (DataNode, NameNode)
- Processing framework– YARN (NodeManager, ResourceManager).
What is the difference between a regular file system and HDFS?
| Regular File Systems | HDFS |
| A small block size of data (like 512 bytes) | Large block size (orders of 64MB) |
| Multiple disks seek large files | Reads data sequentially after single seek |
In Hadoop technology, data can be stored in two different manners. Explain them and which one you prefer
Well, it is possible to store data in a distributed manner among all the machines within a cluster. Another approach is to choose a dedicated machine for the same. The distributed approach is a good option because the failure of one machine doesn’t interrupt the entire functionality within an organization. Although backup can be created for the first case, accessing the backup data and bringing it into the main server can create a lot of time issues. Thus the second option is a good one. It is reliable. However, all the machines within a cluster need to be protected in every aspect in case of confidential data or information.
When the Schema validation is done in the Hadoop approach?
It is done mainly after the loading of the data. Sometimes it even leads to bugs but that can be managed at a later stage. Actually, it follows the scheme of the reading protocol.
For what purpose Hadoop is a good option to consider and Why?
Hadoop is a good option to consider for OLAP systems, data discovery, as well as for Data Analysis. Hadoop has features that make bulk data handling very easy. Because all these tasks have a lot of data to handle, the Hadoop approach can easily be trusted.
Is it possible to add or remove nodes in a Hadoop Cluster?
Yes, this can simply be done. It is one of the prime tasks of a Hadoop administrator.
What exactly do you know about a Checkpoint? Which Name Node is responsible for performing the same?
The process of modifying FSImages is considered as a checkpoint or checkpointing for the FSImages. This is actually an operation that always makes sure of saving of time during the operations. It is performed by the Secondary Name Node.
What do you mean by the term “Block” in the Hadoop?
A block is nothing but a general location which is a smaller unit of a prime storage location. This is because HDFS stores data in block form. It can also be considered an independent unit.
What exactly is the function of jps command in Hadoop?
Hadoop daemons must remain active all the time during a process is going on. Their failure causes a lot of challenges and issues. Jps Command is used to check whether they are working properly or not.
