Off the Grid
Introduction to Grid Computing with GridGain
QJUG
February 2007
Tom Adams Nick Partridge
Workingmouse Veitch Lister Consulting

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 foo:1
bar bar:1
foo bar bar bar:1 foo: 1
split
bar baz baz map
baz:1 reduce
bar: 4
quux bar quux quux:1 baz: 2
baz bar bar bar:1 quux: 1
baz baz:1
bar bar:1

GridGain grid

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

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

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

foo bar quux bar
bar baz baz bar
foo: 1 Master Master bar: 2
bar: 2 Node Node baz: 1
baz: 1 quux: 1
foo bar baz bar
quux bar bar baz
Node Node

Did you say map/reduce?

foo bar foo: 1
bar baz Master bar: 4
quux bar reduce
Node baz: 2
baz bar quux: 1
bar: 2
foo bar
baz: 1
bar baz
quux: 1
foo: 1
quux bar
bar: 2
baz bar
baz: 1
Node map map Node

Show me the types!

foo bar foo: 1
bar baz Master bar: 4
reduce[B, C](List[B], C, (C, B)
quux bar Node
→ C) → List[C] 2
baz:
baz bar quux: 1
bar: 2
foo bar
baz: 1
bar baz
quux: 1
foo: 1
quux bar
bar: 2
baz bar
baz: 1
map[A, B](List[A],
Node A → B) → List[B] Node

Terminology

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task Result
bar: 2
foo bar quux bar baz: 1
bar baz baz bar quux: 1
foo: 1
Job bar: 2 Job
baz: 1
Node Node

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task Result
foo bar baz bar
Job Job
bar baz quux bar
Job Job
Node Node

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task Result
bar baz foo bar quux bar baz bar
Job Job Job Job
Node Node Node Node

What defines a grid?

IP MCast: 228.1.2.4 IP MCast: 228.1.2.5
Node Node
Node Node Node Node

Failover

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task
bar baz foo bar quux bar baz bar
Job Job Job Job
Node Node Node Node

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task
bar baz foo bar quux bar baz bar
Job Job Job Job
Node
X
Node Node Node

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task
bar baz quux bar baz bar
Job bar
foo Job Job
Job
Node
XNode Node Node

foo bar foo: 1
bar baz Master bar: 4
quux bar Node baz: 2
baz bar quux: 1
Task
foo bar bar baz
Job quux bar baz bar Job
Job Job
X X
Node Node Node Node

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