Cassandra summit-2013

Real Time Big Data With Storm, Cassandra, and In-Memory Computing

DeWayne Filppi@dfilppi

Big Data Predictions

“Over the next few years we'll see the adoption of scalable frameworks and platforms for handling streaming, or near real-time, analysis and processing. In the same way that Hadoop has been borne out of large-scale web applications, these platforms will be driven by the needs of large-scale location-aware mobile, social and sensor use.”

Edd Dumbill, O’REILLY

The Two Vs of Big Data

Velocity Volume

We’re Living in a Real Time World…Homeland Security

Real Time Search

Social

eCommerce

User Tracking & Engagement

Financial Services

The Flavors of Big Data Analytics

Counting Correlating Research

Analytics @ Twitter – Counting

How many signups, tweets, retweets for a topic?

What’s the average latency?

Demographics Countries and cities Gender Age groups Device types …

Analytics @ Twitter – Correlating

What devices fail at the same time?

What features get user hooked?

What places on the globe are “happening”?

Analytics @ Twitter – Research

Sentiment analysis “Obama is popular”

Trends “People like to tweet

after watching American Idol”

Spam patterns How can you tell when

a user spams?

It’s All about Timing

“Real time” (< few Seconds)

Reasonably Quick (seconds - minutes)

Batch (hours/days)

It’s All about Timing

• Event driven / stream processing • High resolution – every tweet gets counted

• Ad-hoc querying • Medium resolution (aggregations)

• Long running batch jobs (ETL, map/reduce) • Low resolution (trends & patterns)

This is what we’re here to discuss

VELOCITY + VAST VOLUME = IN MEMORY + BIG DATA

RAM is the new disk Data partitioned across a cluster

Large “virtual” memory space Transactional Highly available Code collocated with data.

In Memory Data Grid Review

Data Grid + Cassandra: A Complete Solution• Data flows through the in-memory cluster async to Cassandra• Side effects calculated• Filtering an option• Enrichment an option• Results instantly available• Internal and external event listeners notified

Simplified Event Flow

Grid – Cassandra Interface Hector and CQL based interface In memory data must be mapped to column families.

Configurable class to column family mapping Must serialize individual fields

Fixed fields can use defined types Variable fields ( for schemaless in-memory mode) need serializers

Object model flattening By default, nested fields are flattened. Can be overridden by custom serializer.

Virtues and Limitations

Could be faster: high availability has a cost Complex flows not easy to assemble or understand with simple

event handlers

Complete stack, not just two tools of many Fast.

Microsecond latencies for in memory operations Fast enough for almost anybody

Highly available/self healing Elastic

Popular open source, real time, in-memory, streaming computation platform.

Includes distributed runtime and intuitive API for defining distributed processing flows.

Scalable and fault tolerant. Developed at BackType, and open sourced by Twitter

Storm Background

Streams Unbounded sequence of tuples

Spouts Source of streams (Queues)

Bolts Functions, Filters, Joins, Aggregations

Topologies

Storm AbstractionsSpout

Topologies

Streaming word count with Storm

Storm has a simple builder interface to creating stream processing topologies

Storm delegates persistence to external providers Cassandra, because of its write performance, is commonly used

Storm : Optimistic Processing Storm (quite rationally) assumes success is normal Storm uses batching and pipelining for performance Therefore the spout must be able to replay tuples on demand

in case of error. Any kind of quasi-queue like data source can be fashioned

into a spout. No persistence is ever required, and speed attained by

minimizing network hops during topology processing.

Fast. Want to go faster? Eliminate non-memory components Substitute disk based queue for reliable in-memory queue Substitute disk based state persistence to in-memory

persistence Asynchronously update disk based state (C*)

Sample Architecture

References Try the Cloudify recipe

Download Cloudify : http://www.cloudifysource.org/ Download the Recipe (apps/xapstream, services/xapstream):

– https://github.com/CloudifySource/cloudify-recipes XAP – Cassandra Interface Details;

http://wiki.gigaspaces.com/wiki/display/XAP95/Cassandra+Space+Persistency Check out the source for the XAP Spout and a sample state

implementation backed by XAP, and a Storm friendly streaming implemention on github: https://github.com/Gigaspaces/storm-integration

For more background on the effort, check out my recent blog posts at http://blog.gigaspaces.com/ http://blog.gigaspaces.com/gigaspaces-and-storm-part-1-storm-clouds/ http://blog.gigaspaces.com/gigaspaces-and-storm-part-2-xap-integration/ Part 3 coming soon.

Twitter Storm With Cassandra

Storm Overview

Streams Unbounded sequence of tuples

Spouts Source of streams (Queues)

Bolts Functions, Filters, Joins, Aggregations

Topologies

Storm ConceptsSpouts

Topologies

Challenge – Word Count

Word:Count

Tweets

• Hottest topics• URL mentions• etc.

Streaming word count with Storm

Supercharging Storm Storm doesn’t supply persistence, but provides for it Storm optimizes IO to slow persistence (e.g. databases) using

batching. Storm processes streams. The stream provider itself needs to

support persistency, batching, and reliability.

Tweets, events,whatever….

XAP Real Time Analytics

Two Layer Approach Advantage: Minimal

“impedance mismatch” between layers.– Both NoSQL cluster

technologies, with similar advantages

Grid layer serves as an in memory cache for interactive requests.

Grid layer serves as a real time computation fabric for CEP, and limited ( to allocated memory) real time distributed query capability.

In Memory Compute Cluster

NoSQL Cluster

Raw And Derived Events

Simplified Architecture

Flowing event streams through memory for side effects Event driven architecture executing in-memory Raw events flushed, aggregations/derivations retained All layers horizontally scalable All layers highly available Real-time analytics & cached batch analytics on same scalable

layer Data grid provides a transactional/consistent façade on NoSQL

store (in this case eliminating SQL database entirely)

Key Concepts

Keep Things In Memory

Facebook keeps 80% of its data in Memory (Stanford research)

RAM is 100-1000x faster than Disk (Random seek)• Disk: 5 -10ms • RAM: ~0.001msec

Take Aways A data grid can serve different needs for big data analytics:

Supercharge a dedicated stream processing cluster like Storm.– Provide fast, reliable, transactional tuple streams and state

Provide a general purpose analytics platform– Roll your own

Simplify overall architecture while enhancing scalability– Ultra high performance/low latency– Dynamically scalable processing and in-memory storage– Eliminate messaging tier– Eliminate or minimize need for RDBMS

Realtime Analytics with Storm and Hadoop http://www.slideshare.net/Hadoop_Summit/realtime-analy

tics-with-storm Learn and fork the code on github:

https://github.com/Gigaspaces/storm-integration

Twitter Storm: http://storm-project.net

XAP + Storm Detailed Blog Post http://blog.gigaspaces.com/gigaspaces-and-storm-part-2-xap-integration/

References

Cassandra summit-2013

Technology

Cassandra at eBay - Cassandra Summit 2012

C* Summit EU 2013: No Whistling Required: Cabs, Cassandra, and Hailo

StratioDeep: an Integration Layer Between Spark and Cassandra - Spark Summit 2013

C* Summit EU 2013: The Cassandra Experience at Orange

Cassandra Summit 2014: Lesser Known Features of Cassandra 2.1

C* Summit EU 2013: Apache Cassandra 2.0 — Data Model on Fire

Cassandra Summit 2015

C* Summit EU 2013: Cassandra on Flash: Performance & Efficiency Lessons Learned

Cassandra summit LWTs

C* Summit 2013: Splunk + Cassandra = New value to business by Eddie Satterly

Cassandra Summit EU 2014 - Testing Cassandra Applications

Cassandra summit lighttalk-stratio

C* Summit 2013: How Not to Use Cassandra by Axel Liljencrantz

C* Summit EU 2013: Blending Cassandra Data Into The Mix

Cassandra at eBay - Cassandra Summit 2013

C* Summit EU 2013: Effective Cassandra Development with Achilles

Cassandra Summit 2014: Performance Tuning Cassandra in AWS

Cassandra Summit 2014: Launching PlayStation 4 with Apache Cassandra

C* Summit 2013: Time-Series Metrics with Cassandra by Mike Heffner

C* Summit EU 2013: Cassandra Internals