Low-Latency Streaming Data Processing in Hadoop

InSemble Inc. http://www.insemble.com

Agenda

Reference Architecture for Low Latency Streaming1

Storm 4

Kafka3

Flume2

Demo5

Hadoop Ecosystem

Source: Apache Hadoop Documentation

Cloudera Platform

Hortonworks Data Platform(HDP)

Real time Stream Processing Architecture with Hadoop

Flume Architecture

• Distributed system for collecting and aggregating from multiple data stores to a centralized data store

• Agent is a JVM that hosts the Flume components

• Channel will store message until picked by a sink

• Different types of Flume sources

• Source and Sink are decoupled

Consolidation Architecture

Multiplexing Architecture

Kafka Introduction

• Messaging System which is distributed, partitioned and replicated• Kafka brokers run as a cluster• Producers and Consumers can be written in any language

Topic

• Ordered, immutable sequence numbers• Retains messages until a period of time• “Offset” of where they are is controlled by the consumer• Each partition is replicated and has “leader” and 0 or more “follower”. R/W

only done on leader

Producers and Consumers

• Producer controls which partition messages goes to• Supports both Queuing and Pub/Sub

– Abstraction called Consumer group• Ordering within Partition

– Ordering for subscriber has to be done with only one subscriber to that partition

Storm Introduction

• Distributed real time computational system– Process unbounded streams of data– Can use multiple programming languages– Scalable, fault-tolerant and guarantees that data will be processed

• Use Cases– Real time analytics, online machine learning– Continuous Computation– Distributed RPC– ETL

• Concepts– Topology– Spouts– Bolts

Concepts

• Storm Cluster– Master node(Nimbus)

• Distributing code• Assigns tasks to machines• Monitors for failures

– Worker nodes(Supervisor)• Starts/stops worker processes• Each worker process executes subset of a topology

– Zookeeper• Coordinates between Nimbus and Supervisors• Nimbus and Supervisors completely stateless• State maintained by Zookeeper or local disks

Details

• Stream – Unbounded sequence of tuples

• Spout(write logic)– Source of stream. Emits tuples

• Bolt(write logic)– Processes streams and emits tuples

• Topology– DAG of spouts and bolts– Submit a topology to a Storm cluster– Each node runs in parallel and parallelism is controlled

Stream groupings

• Tells a topology how to send tuples between two components• Since tasks are executed in parallel, how do we control which tasks the

tuples are being sent to

Demo - Twitter TopN Trending Topic

• Use Flume Twitter Source to ingest data and publish event to Kafka topic

• Use Storm as an Real-Time event processing system to calculate TopN trending topic

• Use Redis to store the TopN Result• Use Node.js/JQuery for visualization

Flow Chart

Twitter Twitter Source

Flume Agent

Mem Channel Kafka Sink

KafkaKafka SpoutParse Twitter BoltCount Bolt

TopN Ranker Bolt Report Bolt

Storm

RedisNode.js + JQuery

Twitter Source Mem Channel Kafka Sink

Flume Agent — Source

Flume Agent — Channel

Flume Agent — Sink

Storm Topology Design

Submit Topology to Cluster

ParseTweetBolt Code

ParseTweetBolt Code

ParseTweetBolt Code