OGSADAI Tomorrow Resources and Persistence

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OGSA-DAI Tomorrow Resources and Persistence

• SIMDAT Grid Infrastructure Workshop
• IT Innovation Centre
• 5-6 December 2006

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Multi-resource requests
One
Data Resource
Data
MyDRER
Two
Data Request Execution Service
Data Request Execution Resource
Data Resource
Data
Three
Data Resource
Data
Perform Document myQuery(One) myQuery(Two) myInteg
rateData myTransformData myUpdate(Three)
Client
Client-server interaction
Service-resource association
Resource-resource association
Resource-database association
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An expanded resource model
One
Data Resource
Data
MyDRER
Two
Data Request Execution Service
Data Request Execution Resource
Data Resource
Data
Three
Data Resource
Data
Data Resource Information Service
Client
Session
Session
Session
MySession123
Session Management Service
Session
Session
Request
MyRequest123456
Request Management Service
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Data transport
Perform Document (3.0) createDataSink(MySink) myQu
ery(MyDR) createDataSource(MySource)
Perform Document (2.2) inputStream(MySink) myQuery
() outputStream(MySource)
MyDRER
MyDR
Data Request Execution Service
Data Request Execution Resource
Client
Data Resource
Data
DataSink Service
DataSource Service
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Data transport
Perform Document (2.2) inputStream(MySink) myQuery
() outputStream(MySource)
Perform Document (3.0) createDataSink(MySink) myQu
ery(MyDR) createDataSource(MySource)
MyDRER
MyDR
Data Request Execution Service
Data Request Execution Resource
Client
Data Resource
Data
MyRequest
Request
DataSink Service
DataSource Service
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Data transport
Perform Document (3.0) createDataSink(MySink) myQu
ery(MyDR) createDataSource(MySource)
Perform Document (2.2) inputStream(MySink) myQuery
() outputStream(MySource)
MyDRER
MyDR
Data Request Execution Service
Data Request Execution Resource
Client
Data Resource
Data
MyRequest
Request
DataSink Service
MySink
DataSink
MySource
DataSource
DataSource Service
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Data transport
Perform Document (2.2) inputStream(MySink) myQuery
() outputStream(MySource)
Perform Document (3.0) createDataSink(MySink) myQu
ery(MyDR) createDataSource(MySource)
MyDRER
MyDR
Data Request Execution Service
Data Request Execution Resource
Client
Data Resource
Data
MyRequest
Request
DataSink Service
Client
MySink
DataSink
MySource
DataSource
DataSource Service
Client
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Persistence
Data
Another OGSA-DAI Server
OGSA-DAI Server
Data Resource Information Service
Data Resource
Data Request Execution Service
Data Request Execution Resource
Client
OGSA-DAI State
Session Management Service
Session
Session
Session
Request Management Service
Session
Session
Request
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Persistence

• Caching
• Reduce overheads of OGSA-DAI-database
  communications
• Allows configuration and state to persist between
  container shutdowns/crashes
• Sticky resources
• e.g. data sources and sinks
• In-memory only available via server that
  created them
• API
• File-based implementation for backwards
  compatibility
• Relational implementation for compatibility with
  common OGSA-DAI databases
• Extensibility point

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Scalability and robustness
OGSA-DAI cluster
OGSA-DAI State
Front-end Router
Client
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Scalability and robustness

• Release 3 will afford future provision of
  clustering and load balancing
• Clustered OGSA-DAI servers
• Different JVM
• Different machine
• Load balancer
• Simple e.g. round robin
• Complex e.g. decide on basis of current load of
  each server
• Scalable
• Increases number of requests that OGSA-DAI can
  handle concurrently
• Robust
• Seamless operation in the face of errors e.g.
  server failures
• Sticky sessions and resources
• Session and resource state may be
  non-serializable or be lightweight in-memory
  components
• Need to dispatch resources to their owner JVM

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The End

• Questions?

http//www.ogsadai.org.uk