1. DBE Execution Environment
Miguel Vidal
Technical Coordinator

2. What?
• A B2B platform for all Europe wide SME's
• An integrated, distributed pervasive network of local digital ecosystems for
small business organisations and for local e-governance which cooperate
exchanging dynamically resources, applications, services and knowledge.
• It should be for Business, what the WWW was for end users

3. • Imagine a world where computers fix their
own problems before you even know
something is wrong.
• Imagine you can use self-managing
computing systems to control an increasingly
complex and expensive IT environment.
• Imagine make your systems resilient,
responsive, efficient, and secure without
human intervention.
Imagine...

4. DBE: A different way to do it

5. How?
• Without a single owner (Using a P2P
platform)
• Without a single point of failure
(resilient by means of high
redundancy)
• Without System Architect, System
Administrator
• Self-Managed, Self-Heal, Self-
optimized, Self-configured, Self-
protected
• With learning capabilities to substitute
the human operator

6. Exponential Network Scale-free Network
Airlines
What does it mean?

7. Condensation in evolving networks

8. The sustanaible growing model

9. Local decisions: Game Theory
• Which is the self-fish strategy
better for the wole system?
• Wich non zero sum games?
• How many players involved?
• How many times the same game
will be played?
• What are winning the players?

10. Diffusion- Reaction
(Turing's Morphogenesis)
• How far can arrive our messages?
• Which are the minimum number of nodes to
have a network?
• Which are the maximum number of nodes in
the network?
• Which are the limits of the network?
• Which organizations will stay together?
• How many different players are needed?
• Which patterns will emerge spontaneously?
∂ 
∂t
w
∂
∂ z
=
∂
∂ z
K
∂
∂ z
 f i a1, a2, ...,an

11. Complexity & Stability
• Which are the stable solutions?
• Are such stable solutions predictible?
• Under which conditions we can
recover the system?
Xt+1
= Xt
* (1-Xt
)

12. Design principles
Data management beyond the
centralised system approach
Loosely coupled trust and security
mechanisms
Robustness vs completness
Architecture by participation
Fractal software model
The software gets better the more
people use it
The network scales better the
more people use it

13. Execution Environment (ExE)
• The execution environment is
made by a container (ServENT-
http://swallow.sourceforge.net/) and several
services:
– Webapp (servlet container)
– Distributed storage system (DSS)
– Accounting filter and metering service.
– KnowledgeBase and SemanticRegistry.
– Identity.
– Portal.
– Habitat service and EvE filter

14. LANLAN
DBE ServENT: Service invocation
ServentServent
DBE DesktopDBE Desktop
clientclient
BEBE
service
adapter
1-Make
request
2-Route
request
3-Delegate
on adapter
4-Call
Back-End
Acct
system
Acct
system
Notify Notify
ServentServent

15. DBE ServENT in detail

16. DBE ServENT in detail

17. ServENT - Protocol independent
• There is a servent-to-servent invocation
interface that can be implemented for each
protocol we can handle.
• Only serialization has been implemented.

18. ServENT - Filters
• The server side allow the interception and
filtering of request and responses.
• Each service deployed can declare which
filters use and which parameters.
• Filters can be applied on specific methods

19. ServENT - Handlers
• Services can deploy their own handlers to
add http/html access.
• Services with handlers offer both: HTML and
DBE functionality.
• There is a default handler included that
allow user not to code but write velocity
(http://jakarta.apache.org/velocity) pages.

20. ServENT - P2P Interface
• There is a P2P interface implemented
nowadays with FADA (http://fada.sourceforge.net/)
• A new improved FADA or another P2P
solution can be used.

21. ServENT - IP Monitorization
• The ServENT auto-discovers its own IP
during execution, trying to discard privates.
• IP is checked periodically against another
ServENT. If IP changes a message is sent
to all ServENT components.
• For local calls the local IP is used

22. Deploy a service
• DAR (DBE Archive) file is unzipped
in a directory
• There is a ClassLoader for each
service with its libraries and
configuration files. Modifications in
runtime are possible
• Service provider knows nothing
about Fada
• We control the full deployment
process to check results fail with
control

23. ServiceContext (i)
Service can get the Service Context in
the init method
• The Servent manages different context
for each service, each one with
different security policies
• Service params are placed in the
deployment file
• It must be easy for deployed services to
get advantage of the Servent for getting
other DBEServices
• getService(String id) method allow
services to get and invoke local or
remote DBEServices using its interface.

24. ServiceContext (ii)
• Because DBE Services are deployed by the ServENT, it is very easy
for the ServENT to provide these local services.
• Due to the fact that the servent controls FADA and it can provide UI,
DynamicProxy and PA, it must be very easy for the ServENT to
provide these services even if its deployed in another ServENT.

25. Services as a resource
• If services are deployed as a file, it makes sense this file can be recovered
from one servent to deploy automatically in another
• If we can save some state about the running service, the new service will
keep its status when deployed
• If temporally files don't use DSS but a tmp directory, these tmp files also can
be recovered

26. ServENT interface
• The core ServENT implementation used to deploy and undeploy services is a
CoreService itself. It must provide some security restrictions to be used by other
servents or services.
• Servent service can be also called through an HTTP interface. Because it is a
service it can provide an UI too.

27. Execution Environment (ExE)

28. ExE – Webapps Application
• A core DBE service uses Jetty (http://jetty.mortbay.org)
as servlet container in the Execution
Environment (ExE).
• ExE uses this servlet container to integrate
activeBPEL, Portal and OpenLaszlo.

29. • Java Virtual Machine 1.4
• RAM 64 Mb
– ServENT alone 49692 kB .
– With core services deployed 53824 kB.
• Hard Disk 90 Mb (91915 kB)
• Bandwidth 128 Kb
Requirements

30. e-Business by
collaboration
Beginning
"An integrated, distributed pervasive
network of local digital ecosystems for
small business organisations and for local
e-governance which cooperate
exchanging dynamically resources,
applications, services and knowledge.”