Quicksilver

Summary

• Intro
• IPC Fundamentals to System Services
  • Building Distributed IPC and Transactions
    • Transaaction Management
    • Distributed Transaction
  • Upshot of bundling IPC and Recovery
• Implementation Notes

Intro

Quicksilver tries to make recovery a first-class citizen in the OS.

IPC Fundamentals to System Services

IPC happens via a service queue

• Multiple servers can wait on service queue by calling offer

Building Distributed IPC and Transactions

Transaction => secret sauce for recovery management

• Lightweight version
  • Non-ACID

Creator of transaction is default owner

Transaaction Management

Coordinator can be different from owner

Distributed Transaction

Commit initiated by coordinator

Upshot of bundling IPC and Recovery

Reclaim resources

• breadcrumbs left behind by failed clients/services

No extra mechanisms for recovery

• Only mechanism is in OS
• Policy up to each service
  • Low overhead for simple services
  • Weighty mechanisms for services such as FS

Implementation Notes

Log Maintenance

• Transaction Managers (TMs) write log records for recovering persistent state
• Frequency of “log force” implies performance
• Services have to choose mechanisms commensurate with their recovery requirements