Managing External Workload with BSP Time Wrap Malcom Low University of Oxford

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Managing External Workload with BSP Time Wrap
Malcom Low (University of Oxford)

• Vinay Sachdev
• CSCI 6900 - Spring 2003

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Layout

• Introduction to BSP Time Wrap
• Dynamic Load Balancing(DLB) using BSP Time Wrap
• BSP-TW DLB for external workload Algorithm
• Experiments

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Introduction BSP Time Wrap

• Most studies on parallel simulation conducted on
  dedicated systems
• BSP stands for Bulk Synchronous Protocol
• A general purpose approach to parallel computing
  thats allows separation of concerns b/w
  computation,communication and synchronization
  concerns

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Introduction BSP Time Wrap

• BSP programming model consist of P processors
  linked by inter-connecting n/w and each with its
  own pool of memory
• Each processor executes a series of super step
  have ordered steps 1)local computation 2)global
  communication 3)barrier synchronization

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Introduction BSP Time Wrap
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Related Work

• Past studies of DLB algorithms for optimistic
  simulation protocols have focused on metrics to
  measure workload
• Burdorf and Marti local simulation times matrix
• Carothers and Fujimoto background execution

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DLB for BSP Time Wrap
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BSP- TW for external load
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BSP- TW for external load
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Experiments

• Manufacturing Simulation Model
• Mu Assign LPs in round robin to processors
• Mb Assign consecutive block of LPs
• onto same processor
• Persistent WL Start to end
• Transient WL - Introduced after some time and
  lasts a fixed duration

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Persistent Workload
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Transient Workload
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Multiprocessor
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Conclusion

• Algorithm described has facilities to handle
  computation and communication imbalance, optimize
  look ahead and manage interruption from external
  workload
• Shows promise , presence of transient workload
  can result in high overhead in migrating LP to
  and fro b/w processors.