Deliverable D4 Transactional Engine

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Deliverable D4Transactional Engine

• Francisco Pérez, Marta Patiño, Ricardo Jiménez
• Distributed
• Systems
• Laboratory
• Universidad Politécnica de Madrid (UPM)

Lsd
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Goal

• This deliverable aims to provide support for
  advanced transaction models.
• We have adopted the Java Activity Service
  specification to provide this support.

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Overall Architecture

• The Java Activity Service is structured in two
  components
• The activity service itself.
• One or more high level services.
• The activity service is a kind of low level
  general-purpose engine for registering events.
• A high level service implements a particular
  advanced transaction model.

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Overall Architecture

• Users only access high level services (HLSs).
• The Java activity service only specifies the
  interface between HLSs and the activity service.
• HLS functionality is not constrained in any other
  way.

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Activity Service
Client App.
Begin/End Activity
Action invocations
HLS
Begin/End Activity AddAction BroadcastSignal
Suspend/Resume
Suspend/Resume
GetSignalSet
Begin/End Txn
AS
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Open Nested Transactions
Client App.
Begin/End Activity
Comp. Action Invocations
Open Nested HLS
Begin/End Activity AddAction BroadcastSignal
Suspend/Resume
Suspend/Resume
GetSignalSet
Begin/End Txn
AS
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Integration with CSs

• The HLS will be used by CSs to bracket advanced
  transactions.
• Since our HLSs will be accessible through JNDI
  and running on the application server, the
  integration with CSs should be straightforward.
• It should be noticed that the activity service,
  as it happens with JTA/JTS, it is only aware of
  what is done within the application server by
  EJBs.
• This means that only CSs whose logic is
  implemented as EJBs can really exploit the Java
  activity service.

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What will be delivered

• A basic implementation of the Java Activity
  Service
• No context propagation.
• No context groups.
• Implemented as an mbean in JBoss.
• As suggested by Maartens, an implementation of a
  concrete advanced transaction model
• A high level service implementing the open nested
  transactions.
• Implemented as an mbean in JBoss.
• Based on a JTA and the Java activity service.

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Extensions for later deliverables

• Implementation of web service interoperability.
• Implementation of servlets for intercepting
  invocations within a transactional context
  (ws-coordination/ws-transaction).
• Implementation of the ws-coordination/ws-transacti
  on services (as web services).
• Use of the activity service to coordinate
  business activities and distributed atomic
  transactions.

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Extensions for later deliverables

• Completion of the full activity service
  specification
• Context propagation.
• Context groups.
• Implementation of a generic high level service
• The vision is that it will be customizable in a
  declarative way.