Off the Grid

QJUGFebruary 2007

Nick PartridgeVeitch Lister Consulting

Tom AdamsWorkingmouse

Introduction to Grid Computing with GridGain

Why are we here?

Large distributed application

Grid-based solution worked

Flow

Grid?•Multiple independent computing clusters which act like a

"grid" (Wikipedia)

•Many nodes, each node is indistinguishable from other nodes

•Complete machines over co-located CPUs?

•Multiple processes?

•Commodity hardware?

•Homogenous machines?

A tale of two grids

Partition data across grid

Partition processing across grid

http://www.jroller.com/nivanov/entry/grid_computing_compute_grid_data

Selection

Requirements•Callable from a Rails webapp

•Real-time - synchronous responses less than 30 seconds

•Large dataset - 100 GB (computation runs across all data)

Rails webapp•Simple document-literal web service

•Ruby - soap4r

•Java - GlassFish, Spring-WS

•Not really interesting for this talk... see Brisbane.rb

Data•Read-only

•Full control

•45 TB (became 100 GB with pre-processing)

•SQL? 3 tables, one query w/ 2 joins

Don’t want to roll our own

(Row) database good enough

And we can federate them

Result?

http://battellemedia.com/archives/2007_01.php

What about BigTable?

Column database

Result?

http://failblog.wordpress.com/2008/01/29/satellite/

Where are we?

Progress•Don’t need to distribute data ⇒ no data grid

•No off the shelf solutions that scale/go fast

•Understand data better ⇒ happy to roll our own as fallback

Data solution

Data•CSV files on filesystem (now binary)

•Directories form indices

•Data files broken up into chunks

What about the code?http://giapet.net/wp-content/uploads/2007/05/luluwtf.gif

Need to distribute the computation

Options?

Erlang

Scala

Java

Java frameworks•Hadoop

•GridGain

•Oracle Coherence

•GigaSpaces

•Terracotta

•JavaSpaces/Jini

•Shoal

GridGain

GridGain•“fully open source full-stack grid computing platform for Java”

•Map/reduce-based computation

•Easy to setup and use

•Can be extended via SPI implementations

•Just works

•“Scalable” (we’ve had it up to 32 nodes)

Map/reduce

When does it work•When data is independent (pure/referentially transparent)

•When data can be combined (reduce) based solely on input

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

map

foo barbarbazquuxbarbazbar

foo:1bar:1bar:1baz:1quux:1bar:1baz:1bar:1

reducesplit

GridGain grid

Grid

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

?

Node

foo barbar baz

foo: 1bar: 2baz: 1

Node

quux barbaz bar

bar: 2baz: 1quux: 1

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node

foo barbar baz

foo: 1bar: 2baz: 1

Node

quux barbaz bar

bar: 2baz: 1quux: 1

foo barbar baz

MasterNode

Node

foo bar

Node

quux bar

bar: 2baz: 1quux: 1

MasterNode

quux barbaz bar

bar baz

foo: 1bar: 2baz: 1

baz bar

Did you say map/reduce?

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node

foo barbar baz

foo: 1bar: 2baz: 1

Node

quux barbaz bar

bar: 2baz: 1quux: 1

reduce

map map

Show me the types!

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node

foo barbar baz

foo: 1bar: 2baz: 1

Node

quux barbaz bar

bar: 2baz: 1quux: 1

map[A, B](List[A], A → B) → List[B]

reduce[B, C](List[B], C, (C, B) → C) → List[C]

Terminology

Task

foo barbar bazquux barbaz bar

MasterNode

Node

Job

foo barbar baz

foo: 1bar: 2baz: 1

Node

bar: 2baz: 1quux: 1

Job

quux barbaz bar

Result

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node Node

Jobbar baz

Job

foo bar

Task

foo barbar bazquux barbaz bar

Jobquux bar

Job

baz bar

Result

foo: 1bar: 4baz: 2quux: 1

Result

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node NodeNode Node

Jobbar baz

Jobfoo bar

Jobquux bar

Jobbaz bar

Task

foo barbar bazquux barbaz bar

What defines a grid?

Node

Node Node

IP MCast: 228.1.2.4

Node

Node Node

IP MCast: 228.1.2.5

Failover

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node NodeNode Node

Jobbar baz

Jobfoo bar

Jobquux bar

Jobbaz bar

Task

foo barbar bazquux barbaz bar

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node NodeNode Node

Jobbar baz

Jobfoo bar

Jobquux bar

Jobbaz bar

Task

foo barbar bazquux barbaz bar

X

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node NodeNode Node

Jobbar baz

Jobquux bar

Jobbaz bar

Task

foo barbar bazquux barbaz bar

XJob

foo bar

foo: 1bar: 4baz: 2quux: 1

MasterNode

Node NodeNode Node

Jobquux bar

Jobbaz bar

Task

foo barbar bazquux barbaz bar

XX

Jobbar baz

Jobfoo bar

Task execution

http://www.gridgain.com/javadoc/org/gridgain/grid/GridTask.html

GridGain demo

The good, the bad, the ugly

Just works, fast, easy, extensible, scalable

Error messages, doco, code quality, coupling, odd APIs,

management overview

Nomenclature, JMS?

References•http://wiki.workingmouse.com/

•http://www.gridgain.com/

•http://labs.google.com/papers/mapreduce.html