REAL TERRACOTTA
Real-world scalability patterns with Terracotta
SERGIO BOSSA
Pro-Netics / Sourcesense
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

About Me
Software architect and engineer
✔
http://www.pronetics.it
➔
http://www.sourcesense.com
➔
Blogger
✔
http://sbtourist.blogspot.com
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Open Source Enthusiast
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➔ Lead at Scarlet - Clustering for Jira
http://scarlet.sf.net
➔
Committer at Spring Modules
➔
http://springmodules.dev.java.net
➔
Committer at Terracotta Forge
➔
http://forge.terracotta.org
➔
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Agenda
Do I need a cluster?
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Terracotta concepts.
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Scalability patterns with Terracotta.
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Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Do I need a cluster?
The old, dummy, question:
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➔ Do I need a clustered architecture?
The correct one:
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➔ Do I need scalability?
➔ Do I need availability?
➔ Nowadays, the answer is: yes, you need.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Why should I need a cluster?
Several changes in the social and market landscape ...
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In a few words:
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➔ More and more users surfing the web.
➔ More and more hardware at cheaper price.
➔ More and more processors ... even on a single machine.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

What should I use for my cluster?
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

The Terracotta Revolution
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

The Terracotta Revolution
Transparent clustering.
✔
➔ Everything happens under the hood.
Easy to work with.
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➔ If you know Java, you can cluster your application with
no-to-minimal code changes.
➔ Deep integration with common frameworks and patterns.
Optimized for performance.
✔
➔ No cross-node communication.
➔ Built on the concept of diff.
Open Source.
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➔ With a great community.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Overview
Network Attached Memory
✔
➔ All cluster nodes share part of their memory heap: a
shared object graph starting from one or more roots.
➔ Shared objects changes are propagated at the byte
level: only the different bytes get propagated!
➔ Shared objects changes are delimited by lock-guarded
transactions.
➔ Shared objects are backed by the cluster server
filesystem.
➔ With preserved Java semantics (i.e. object identity)!
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Overview
Hub-and-Spoke network architecture
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➔ A central cluster server with one or more cluster client
nodes.
➔ Clients talk only with the server.
➔ Server can be put in active-passive mode (no SPOF).
➔ For enterprise customers only: server can be put in
active-active mode (no SPOB).
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Details
Bytecode instrumentation
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➔ Instrument classes in order to:
➔ Share classes among cluster nodes.
➔ Intercept and propagate changes.
➔ Apply transactions.
➔ Distribute method invocations.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Details
Roots
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➔ AKA super-static: created only for the first time, and then
shared among all cluster nodes.
➔ Start of the shared object graph: all objects reachable
from roots are shared among all cluster nodes.
➔ Except transient ones.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Details
Locks
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➔ Every read or write operation on a shared object state
must be guarded by locks.
➔ Synchronized blocks.
➔ java.util.concurrent.locks.ReentrantReadWriteLock
➔ Acting as a transaction boundary.
➔ Acting as a change propagation boundary.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Details
Distributed Method Invocation
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➔ Methods called on a shared object from a cluster node,
are automatically fired on the same object instance of all
other cluster nodes.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Technology
Details
Declarative configuration:
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➔ XML file.
➔ Java annotations.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Quick Start
Plan
Identify roots and related shared object graphs.
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Identify transactional methods.
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Identify classes that need to be instrumented.
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Identify distributed methods (optional).
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Choose your cluster deployment configuration:
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➔ How many client nodes?
➔ How many server nodes?
➔ How much memory?
➔ ...
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Terracotta Quick Start
Operate
Configure the cluster.
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Start the Terracotta cluster server:
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sh tc_home/bin/start-tc-server.sh -f path/to/tc-conf.xml
Start the Terracotta cluster client(s):
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TC_INSTALL_DIR=...
TC_CONFIG_PATH=...
. $TC_INSTALL_DIR/bin/dso-env.sh -q
export JAVA_OPTS=${TC_JAVA_OPTS}
java ...
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

What about real world scalability?
Feeling like lost at sea?
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Scalability in the real world
We need some patterns!
Cache your data in a distributed fashion.
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Partition your cached data and collocate with your
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processing.
Asynchronously write-behind to your back-end.
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Asynchronously de-couple components communication.
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Asynchronously de-couple components processing.
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Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Data-affinity caching
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Data-affinity caching
In a nutshell
Key concepts:
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➔ Use a partition function for grouping related entries on
the same distributed cache instance.
➔ Use the partition function to look up the cache instance
and put/get related entries.
➔ Process the cached data on the same node it belongs
to.
Key features:
✔
➔ No network traffic between cache instances.
➔ Distributed load.
➔ Higher scalability.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Data-affinity caching
With Terracotta
Use:
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➔ Tim-Tree-Map-Cache
http://forge.terracotta.org/releases/projects/tim-tree-map-cache/
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Key classes:
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org.tc.cache.CacheFactory
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org.tc.cache.ITerracottaCache
➔
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous write-behind
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous write-behind
In a nutshell
Key concepts:
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➔ Always write and read from your (distributed) cache.
➔ Asynchronously schedule writes to the storage.
Key features:
✔
➔ Higher throughput.
➔ Load throttling.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous write-behind
With Terracotta
Use:
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➔ Tim-Async
http://forge.terracotta.org/releases/projects/tim-async/
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Key classes:
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org.terracotta.modules.async.AsyncCoordinator
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org.terracotta.modules.async.ItemProcessor
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Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous messaging
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous messaging
In a nutshell
Key concepts:
✔
➔ Connects application components through pipes.
➔ Configure processing filters to elaborate messages and
make them flow through pipes.
Key features:
✔
➔ De-coupled application components.
➔ Higher reliability.
➔ Higher scalability.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous messaging
With Terracotta
Use:
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➔ Tim-Pipes
http://forge.terracotta.org/releases/projects/tim-messaging/
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Key classes:
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org.terracotta.message.topology.TopologyManager
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org.terracotta.message.topology.Topology
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org.terracotta.message.routing.Router
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org.terracotta.message.pipe.Pipe
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org.terracotta.message.pipe.PipeProcessor
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org.terracotta.message.subscriber.Subscriber
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org.terracotta.message.subscriber.SubscriberProcessor
➔
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous processing
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous processing
In a nutshell
Key concepts:
✔
➔ Create a set of tasks.
➔ Submit tasks to a master.
➔ Tasks will be executed by workers.
➔ Eventually wait for tasks to be completed.
Key features:
✔
➔ De-coupled execution of expensive tasks.
➔ Parallel execution of tasks.
➔ Customisable routing logic.
➔ Load distribution.
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Asynchronous processing
With Terracotta
Use:
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➔ Tim-MasterWorker
http://forge.terracotta.org/releases/projects/tim-messaging/
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Key classes:
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org.terracotta.executor.DistributedExecutorService
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org.terracotta.executor.DistributedCompletionService
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org.terracotta.workmanager.statik.StaticWorkManager
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org.terracotta.workmanager.statik.StaticWorker
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org.terracotta.workmanager.dynamic.DynamicWorkManager
➔
org.terracotta.workmanager.dynamic.DynamicWorker
➔
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Conclusion
Enjoy scalability challenges!
Design your scalable architecture ...
✔
Program in plain old Java ...
✔
Run with Terracotta!
✔
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009

Q&A
Sergio Bossa - sergio.bossa@pronetics.it - Pro-Netics / Sourcesense
Javaday Roma III Edizione – 24 gennaio 2009