Answer:- InputFormat the input data, and then it returns a RecordReader instance that defines the classes of the key and value objects, and provides a next() method that is used to iterate over each input record.

Answer:- MSLAB stands for Memstore-Local Allocation Buffer.

Answer:- Lempel-Ziv-Oberhumer (LZO) is a lossless data compression algorithm that is focused on decompression speed, and written in ANSIC.

Answer:- HBase comes with a tool called hbck which is implemented by the HBaseFsck class. It provides various command-line switches that influence its behavior.

Answer:- Rest stands for Representational State Transfer which defines the semantics so that the protocol can be used in a generic way to address remote resources. It also provides support for different message formats, offering many choices for a client application to communicate with the server.

Answer:- Apache Thrift is written in C++, but provides schema compilers for many programming languages, including Java, C++, Perl, PHP, Python, Ruby, and more.

Answer:- The fundamental key structures of HBase are row key and column key.

Answer:- The Java Management Extensions technology is the standard for Java applications to export their status.

Answer:- Nagios is a very commonly used support tool for gaining qualitative data regarding cluster status. It polls current metrics on a regular basis and compares them with given thresholds.

Answer:- The syntax of describe command is – hbase> describe tablename

Answer:- The exists command is used to check that the specified table is exists or not.

Answer:- MasterServer is used to assign a region to the region server and also handle the load balancing.

Answer:- HBase shell is a java API by which we communicate with HBase.

Answer:- The zookeeper is used to maintain the configuration information and communication between region servers and clients. It also provides distributed synchronization.