Featured post

The Ultimate Cheat Sheet On Hadoop

Top 20 frequently asked questions to test your Hadoop knowledge given in the below Hadoop cheat sheet. Try finding your own answers and match the answers given here.




Question #1 

You have written a MapReduce job that will process 500 million input records and generate 500 million key-value pairs. The data is not uniformly distributed. Your MapReduce job will create a significant amount of intermediate data that it needs to transfer between mappers and reducers which is a potential bottleneck. A custom implementation of which of the following interfaces is most likely to reduce the amount of intermediate data transferred across the network?



A. Writable
B. WritableComparable
C. InputFormat
D. OutputFormat
E. Combiner
F. Partitioner
Ans: e




Question #2 

Where is Hive metastore stored by default ?


A. In HDFS
B. In client machine in the form of a flat file.
C. In client machine in a derby database
D. In lib directory of HADOOP_HOME, and requires HADOOP_CLASSPATH to be modified.
Ans: c




Question…

SAN real configuration ideas to speed the devices

In today’s terms, the technical description of a SAN (Storage Area Network) is a collection of computers and storage devices, connected over a high-speed optical network and dedicated to the task of storing and protecting data. In a nutshell, you use a SAN to store and protect data. 

A SAN uses the SCSI (Small Computer Storage Interconnect) and FC (Fibre Channel) protocols to move data over a network and store it directly to disk drives in block format.
SAN configuration ideas
Photo credit: Srini

SAN Configuration

Today, that high-speed network usually consists of fiber-optic cables and switches that use light waves to transmit data with a connection protocol known as Fibre Channel. (A protocol is a set of rules used by the computer devices to define a common communication language.) More and more, regular Internet protocol (IP)–based corporate networks, and even the Internet, are being used as the network part of a SAN. 

Nowadays Internet is the part of SAN

IP Networks

  • IP networks that are already in place can be used by other storage connection protocols such as iSCSI (internet Small Computer Storage Interconnect) to move and store data.
  • Using a network to create a shared pool of storage devices is what makes a SAN different. A SAN moves data among various storage devices, allows sharing data between different servers, and provides a fast connection medium for backing up, restoring, archiving, and retrieving data. 

SAN Devices

  • SAN devices are usually bunched closely in a single room, but they can also be connected over long distances, making a SAN very useful to large companies. Many of today’s SAN components are pretty much plug-and-play. To create a simple SAN, you just connect all the devices together with cables, and off you go. Creating larger SANs with many storage switches can become complex.

Comments

Popular posts from this blog

AWS Vs Azure Load Balancers Top Insights

Hadoop File System Basic Commands

4 Important Skills You Need for Data Scientists

Hyperledger Fabric: 20 Real Interview Questions