Transcript Title of Event or Presentation

The Eclipse Virgo Experience
at CME Group
Jan Fetyko
03/29/2012
CME Group
CME Group, formerly known as Chicago Mercantile Exchange Holdings
Inc., was founded in 1898 and operates the CME, CBOT, NYMEX, and
COMEX regulatory exchanges worldwide.
It is the world’s leading derivatives marketplace with ~2500 full time
employees and a market capitalization of over $15B.
http://www.cmegroup.com/
© 2012 CME Group. All rights reserved
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Topics
• About our application
• Development strategy
• Getting it running in Virgo
• Web Layer
• Impact on our team
© 2012 CME Group. All rights reserved
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About our application
• Surveillance tool – monitors the state of exchange and the market
• Rewrite of an existing (legacy J2EE) app
• Many services
• Web application(s) that use the services
• Uses: Spring, JDBC, LDAP, EHCache, H2, c3p0, Apache Tiles, snaps
© 2012 CME Group. All rights reserved
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Development strategy
Split all functionality into services / bundles
• Defined interfaces for services
• Skeletons only
© 2012 CME Group. All rights reserved
Authentication
Trades
Authorization
Orders
Configuration
Market Info
Caching
Notifications
Datasource
Quotes
Metrics
Positions
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Implemented the interfaces
• NO OSGi
• Not running in Virgo
• Unit tests with mocks
© 2012 CME Group. All rights reserved
Authentication
Trades
Authorization
Orders
Configuration
Market Info
Caching
Notifications
Datasource
Quotes
Metrics
Positions
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Getting it running in Virgo
Running in Virgo
Most bundles deployed and started without problems
Exposed and used implementations
3rd party libs a big pain
© 2012 CME Group. All rights reserved
Authentication
Trades
Authorization
Orders
Configuration
Market Info
Caching
Notifications
Datasource
Quotes
Metrics
Positions
Virgo



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Breaking in Virgo
Exposed and used implementations
Unable to satisfy dependencies of bundle 'impl-use' at version '1.0.0': Cannot resolve:
impl-use
Resolver report:
An Import-Package could not be resolved.
Caused by missing constraint in bundle <impl-use_1.0.0>
constraint: <Import-Package: com…some.internal; version="0.0.0">
Solution
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Anything internal needs to stay internal
Even a factory should be a “service”: Interface + Impl
Should prevent others to see what is inside the bundle
© 2012 CME Group. All rights reserved
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Breaking in Virgo
•
•
•
•
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3rd party libraries : EHCache
Not OSGi-fyied
Works great as long as no replication is needed
Replication using RMI probably works fine
Replication setup fails if using jgroups – it is loaded using Class.forName(…)
cacheEventListenerFactory.setClass("net.sf.ehcache.distribution.jgroups.JGroupsC
acheReplicatorFactory");
Ehcache-jgroups classes are not in Import-Package, it will throw
ClassNotFoundException
Also, ehcache-jgroupsreplication.jar is not OSGi-fyied
Solution
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Use bnd tool to modify ehcache jar(s)
Create a bnd tool accepted settings file
Push the new ehcache jar into common place (maven repo, git)
© 2012 CME Group. All rights reserved
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Breaking in Virgo
3rd party libraries : EHCache
ehcache bnd tool properties
Bundle-SymbolicName: ehcache-core-2.3.1
Bundle-Version: 2.3.1
Bundle-Name: ehcache-core-2.3.1
Bundle-ManifestVersion: 2
Implementation-Version: 2.3.1
Implementation-Title: EH Cache Core
Export-Package: *;version=2.3.1
Import-Package: org.jgroups.util,*
© 2012 CME Group. All rights reserved
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Breaking in Virgo
3rd party libraries : EHCache
bnd tool properties for ehcache-jgroupsreplication
Bundle-SymbolicName: net.sf.ehcache.jgroupsreplication
Bundle-Version: 1.4
Bundle-Name: net.sf.ehcache.jgroupsreplication
Implementation-Version: 1.4
Implementation-Title: EH Cache jGroups Replication
Export-Package: *;version=1.4
© 2012 CME Group. All rights reserved
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What is happening in caching service
XYZ
Service
On
Node 1
Objects
Caching
Service
On
Node 1
Caching
Service
On
Node 2
Serialize
010011001010110
Deserialize
ClassNotFoundException
in ehcache bundle
© 2012 CME Group. All rights reserved
Breaking in Virgo
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•
3rd party libraries : EHCache
Replication is possible only for objects known to ehcache
Deserialization of keys and values fails with ClassNotFoundException, because your
classes are not in the Import-Package
Solution
•
Store only objects that are known to ehcache – serialize and deserialize them
manually
© 2012 CME Group. All rights reserved
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Breaking in Virgo
3rd party libraries : EHCache
Solution - continued
Public interface CachingService {
CacheElement get(CacheKey key)
}
public interface CacheElement {
Object getValue(Class<?> classLoadingClass);
}
© 2012 CME Group. All rights reserved
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Breaking in Virgo
•
•
•
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3rd party libraries : MANIFEST.MF
It is easier than bnd tool
Faster results
You will learn a lot about MANIFEST.MF which is essential to know OSGi anyway
Most changed settings
• Import-Package
• Export-Package
• Version(s)
After hacking the MANIFEST.MF
•
Use bnd tool to have repeatable results
© 2012 CME Group. All rights reserved
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Web Layer
Web Layer
Virgo snaps
snap
1
host
snap
2
snap
{n}
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Web Layer
Apache Tiles & Spring MVC
Fragments: content
Navigation
Authorization
host
Shared Tiles
Definitions
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snap
1
Snap Tiles
definitions
extend host
definitions
snap
{n}
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Web Layer
Apache Tiles
Host
Tile fragment
Tile
© 2012 CME Group. All rights reserved
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Running in Virgo
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Mini Lessons learned
Design for modularity
Understand class loading
Understand Manifest
If possible use 3rd party libs that are OSGi ready
Avoid serialization across bundles
Web Layer
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For Virgo 2.1, we had to dig through the snaps source and request a tag for a version
that worked in Virgo 2.1 (currently on Virgo 3.0.1)
Snaps + Tiles not the best combination
Provides good flexibility
Snaps provides a single point of entry (filters, security, etc.)
© 2012 CME Group. All rights reserved
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Tooling
Development
Deployment
etc.
Tools
• STS (SpringSource Tool Suite)
• Apache maven + bundlor plugin (SpringSource)
• maven archetypes to create services and web bundles
• Flyway for database versioning
• Firefox + firebug
• No Virgo tooling or Libra
© 2012 CME Group. All rights reserved
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Developer Workflow
• Maven + profiles for easy deployment
• Custom plans in virgo while working on a bundle
<plan name="com.cme.security.plan” ….>
<artifact type="bundle" name="com.cme.web.security" version=”…" />
</plan>
© 2012 CME Group. All rights reserved
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Deployment
• QA and up: Package and deploy everything including Virgo every time
• Everything is scripted including DB schema update (flyway)
• QA time is reduced because changes are only made to a well defined
set of bundles
• Risk of running the wrong code in production is reduced to zero by not
including the bundle in the deployment package
– We have different deployment targets for 2 different internal customers. Their code
cannot impact or risk being deployed together in production.
© 2012 CME Group. All rights reserved
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Team
• OSGi is not the easiest to understand for monolithic app developers
• Virgo is just like any other container to most users
• Once basic concepts are established, there are no issues
• There are few experts who can help everybody else
• 99% of code is not different from a non-OSGi code
• We started with 2 people using Virgo, now there are 16 at CME and 6 in
Brazil
• Today we have 37 service bundles and 23 web bundles
© 2012 CME Group. All rights reserved
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Conclusions of the
Eclipse Virgo experience
Virgo experience conclusions
• Did not hit any Virgo bugs (yet), stable, didn’t experience any crashes
• Problems only come from our code
• Virgo 3.x release improved memory consumption comparing to 2.1
• The learning curve is steep
• Design for modularity upfront is important
• Cannot go back to monolithic app
© 2012 CME Group. All rights reserved
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Q&A
Jan Fetyko
03/29/2012
[email protected]
@jfetyko
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© 2012 CME Group. All rights reserved
Futures trading is not suitable for all investors, and involves the risk of loss. Futures are a
leveraged investment, and because only a percentage of a contract’s value is required to trade,
it is possible to lose more than the amount of money deposited for a futures position. Therefore,
traders should only use funds that they can afford to lose without affecting their lifestyles. And
only a portion of those funds should be devoted to any one trade because they cannot expect to
profit on every trade.
The Globe Logo, CME®, Chicago Mercantile Exchange®, and Globex® are trademarks of
Chicago Mercantile Exchange Inc. CBOT® and the Chicago Board of Trade® are trademarks of
the Board of Trade of the City of Chicago. NYMEX, New York Mercantile Exchange, and
ClearPort are trademarks of New York Mercantile Exchange, Inc. COMEX is a trademark of
Commodity Exchange, Inc. CME Group is a trademark of CME Group Inc. All other trademarks
are the property of their respective owners.
The information within this presentation has been compiled by CME Group for general purposes
only. CME Group assumes no responsibility for any errors or omissions. Although every attempt
has been made to ensure the accuracy of the information within this presentation, CME Group
assumes no responsibility for any errors or omissions. Additionally, all examples in this
presentation are hypothetical situations, used for explanation purposes only, and should not be
considered investment advice or the results of actual market experience.
All matters pertaining to rules and specifications herein are made subject to and are superseded
by official CME, CBOT, NYMEX and CME Group rules. Current rules should be consulted in all
cases concerning contract specifications.
© 2012 CME Group. All rights reserved
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