Book Image

Real-time Analytics with Storm and Cassandra

By : Shilpi Saxena
Book Image

Real-time Analytics with Storm and Cassandra

By: Shilpi Saxena

Overview of this book

Table of Contents (19 chapters)
Real-time Analytics with Storm and Cassandra
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding the Trident API


Trident API supports five broad categories of operations:

  • Operations for manipulations of partitioning local data without network transfer

  • Operations related to the repartitioning of the stream (involves the transfer of stream data over the network)

  • Data aggregation over the stream (this operation do the network transfer as a part of operation)

  • Grouping over a field in the stream

  • Merge and join

Local partition manipulation operation

As the name suggests, these operations are locally operative over the batch on each node and no network traffic is involved for it. The following functions fall under this category.

Functions

  • This operation takes single input value and emits zero or more tuples as the output

  • The output of these function operations is appended to the end of the original tuple and emitted to the stream

  • In cases where the function is such that no output tuple is emitted, the framework filters the input tuple too, while in other cases the input tuple is duplicated...