Asynchronous Replication of Databases
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The document discusses asynchronous replication of databases in large scale systems. It covers consistency criteria for replicated systems, asynchronous replication models including primary copy and update-everywhere, challenges of scaling replication across large systems, and limitations of current full replication techniques with respect to coordination overhead and data freshness at large scales. Examples of MySQL replication are provided and conclusions are presented.
Asynchronous Replication of Databases
- 1. Survey Paper - UCE15 Asynchronous Replication of Databases in Large Scale State Of The Art Master's Degree in Computer Engineering University of Minho
- 2. Survey Paper - UCE15 Agenda Introduction Consistency Criteria Asynchronous Replication Replication in Large Scale and Data Freshness MySQL Conclusions Master's Degree in Computer Engineering University of Minho
- 3. Survey Paper - UCE15 Introduction Master's Degree in Computer Engineering University of Minho
- 4. Survey Paper - UCE15 Introduction Why replicate data? Master's Degree in Computer Engineering University of Minho
- 5. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Master's Degree in Computer Engineering University of Minho
- 6. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Performance Master's Degree in Computer Engineering University of Minho
- 7. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Performance Master's Degree in Computer Engineering University of Minho
- 8. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Performance However... Master's Degree in Computer Engineering University of Minho
- 9. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Performance However... Introduces a constant trade-off between consistency and performance Master's Degree in Computer Engineering University of Minho
- 10. Survey Paper - UCE15 Introduction Why replicate data? Fault-Tolerance Performance However... Introduces a constant trade-off between consistency and performance Need to use adequate replication mechanisms / protocols Master's Degree in Computer Engineering University of Minho
- 11. Survey Paper - UCE15 Introduction Master's Degree in Computer Engineering University of Minho
- 12. Survey Paper - UCE15 Introduction Classification of replication protocols: Master's Degree in Computer Engineering University of Minho
- 13. Survey Paper - UCE15 Introduction Classification of replication protocols: When can updates be performed: Master's Degree in Computer Engineering University of Minho
- 14. Survey Paper - UCE15 Introduction Classification of replication protocols: When can updates be performed: Who can perform updates: Master's Degree in Computer Engineering University of Minho
- 15. Survey Paper - UCE15 Introduction Classification of replication protocols: When can updates be performed: - Lazy (also know as asynchronous) - Eager (also know as synchronous) Who can perform updates: Master's Degree in Computer Engineering University of Minho
- 16. Survey Paper - UCE15 Introduction Classification of replication protocols: When can updates be performed: - Lazy (also know as asynchronous) - Eager (also know as synchronous) Who can perform updates: - Primary copy - Update-everywhere Master's Degree in Computer Engineering University of Minho
- 17. Survey Paper - UCE15 Consistency Criteria Master's Degree in Computer Engineering University of Minho
- 18. Survey Paper - UCE15 Consistency Criteria Key issue, since replication is a solution to achieve fault-tolerance Master's Degree in Computer Engineering University of Minho
- 19. Survey Paper - UCE15 Consistency Criteria Key issue, since replication is a solution to achieve fault-tolerance Correct behaviour in a replicated system must ensure linearizability (also know as one copy equivalence): Master's Degree in Computer Engineering University of Minho
- 20. Survey Paper - UCE15 Consistency Criteria Key issue, since replication is a solution to achieve fault-tolerance Correct behaviour in a replicated system must ensure linearizability (also know as one copy equivalence): ‣ Gives the illusion that a replicated database system is single Master's Degree in Computer Engineering University of Minho
- 21. Survey Paper - UCE15 Consistency Criteria Key issue, since replication is a solution to achieve fault-tolerance Correct behaviour in a replicated system must ensure linearizability (also know as one copy equivalence): ‣ Gives the illusion that a replicated database system is single ‣ Maintain order Master's Degree in Computer Engineering University of Minho
- 22. Survey Paper - UCE15 Consistency Criteria Key issue, since replication is a solution to achieve fault-tolerance Correct behaviour in a replicated system must ensure linearizability (also know as one copy equivalence): ‣ Gives the illusion that a replicated database system is single ‣ Maintain order ‣ Atomicity Master's Degree in Computer Engineering University of Minho
- 23. Survey Paper - UCE15 Consistency Criteria Other Criteria: Increasing popularity of Snapshot Isolation (SI) Strong Serializability Strong Session 1SR Master's Degree in Computer Engineering University of Minho
- 24. Survey Paper - UCE15 Asynchronous Replication Master's Degree in Computer Engineering University of Minho
- 25. Survey Paper - UCE15 Asynchronous Replication Lazy schemes update replicas using separate transactions Master's Degree in Computer Engineering University of Minho
- 26. Survey Paper - UCE15 Asynchronous Replication Lazy schemes update replicas using separate transactions Due to the complexity and performance of eager replication, there is a wide spectrum of lazy schemes Master's Degree in Computer Engineering University of Minho
- 27. Survey Paper - UCE15 Asynchronous Replication Lazy schemes update replicas using separate transactions Due to the complexity and performance of eager replication, there is a wide spectrum of lazy schemes Lazy Replication Models: Master's Degree in Computer Engineering University of Minho
- 28. Survey Paper - UCE15 Asynchronous Replication Lazy schemes update replicas using separate transactions Due to the complexity and performance of eager replication, there is a wide spectrum of lazy schemes Lazy Replication Models: Primary copy Master's Degree in Computer Engineering University of Minho
- 29. Survey Paper - UCE15 Asynchronous Replication Lazy schemes update replicas using separate transactions Due to the complexity and performance of eager replication, there is a wide spectrum of lazy schemes Lazy Replication Models: Primary copy Update-everywhere Master's Degree in Computer Engineering University of Minho
- 30. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Master's Degree in Computer Engineering University of Minho
- 31. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Master's Degree in Computer Engineering University of Minho
- 32. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Most solutions adopt a full replication model Master's Degree in Computer Engineering University of Minho
- 33. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Most solutions adopt a full replication model ➡ Coordination overhead Master's Degree in Computer Engineering University of Minho
- 34. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Most solutions adopt a full replication model ➡ Coordination overhead Most solutions rely on 1-copy-serializability Master's Degree in Computer Engineering University of Minho
- 35. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Most solutions adopt a full replication model ➡ Coordination overhead Most solutions rely on 1-copy-serializability ➡ Limits concurrency Master's Degree in Computer Engineering University of Minho
- 36. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Current techniques have attained some degree of scalability, however there are two main limitations: Most solutions adopt a full replication model ➡ Coordination overhead Most solutions rely on 1-copy-serializability ➡ Limits concurrency ➡ Limits scalability of the system Master's Degree in Computer Engineering University of Minho
- 37. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Master's Degree in Computer Engineering University of Minho
- 38. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Although serializability is guaranteed on lazy replication system with concurrency control techniques and consistency criterion, these techniques do not provide data freshness guarantees: Master's Degree in Computer Engineering University of Minho
- 39. Survey Paper - UCE15 Replication in Large Scale and Data Freshness Transactions may see stale data They may be serialized in an order different from the one in which they were submitted Master's Degree in Computer Engineering University of Minho
- 40. Survey Paper - UCE15 MySQL Master's Degree in Computer Engineering University of Minho
- 41. Survey Paper - UCE15 MySQL MySQL implements asynchronous master-slave replication Master's Degree in Computer Engineering University of Minho
- 42. Survey Paper - UCE15 MySQL MySQL implements asynchronous master-slave replication Uses the primary-copy replication method, supporting two formats of replication: Master's Degree in Computer Engineering University of Minho
- 43. Survey Paper - UCE15 MySQL MySQL implements asynchronous master-slave replication Uses the primary-copy replication method, supporting two formats of replication: Statement-based Master's Degree in Computer Engineering University of Minho
- 44. Survey Paper - UCE15 MySQL MySQL implements asynchronous master-slave replication Uses the primary-copy replication method, supporting two formats of replication: Statement-based Row-based Master's Degree in Computer Engineering University of Minho
- 45. Survey Paper - UCE15 MySQL Replication topologies: Master's Degree in Computer Engineering University of Minho
- 46. Survey Paper - UCE15 MySQL Replication topologies: Master and Multiple Slaves Master's Degree in Computer Engineering University of Minho
- 47. Survey Paper - UCE15 MySQL Replication topologies: Master and Multiple Slaves Ring Master's Degree in Computer Engineering University of Minho
- 48. Survey Paper - UCE15 MySQL Replication topologies: Master and Multiple Slaves Ring Tree Master's Degree in Computer Engineering University of Minho
- 49. Survey Paper - UCE15 Conclusions Master's Degree in Computer Engineering University of Minho
- 50. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Master's Degree in Computer Engineering University of Minho
- 51. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Master's Degree in Computer Engineering University of Minho
- 52. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Primary-copy approach introduces a single point of failure, but simplifies replica control Master's Degree in Computer Engineering University of Minho
- 53. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Primary-copy approach introduces a single point of failure, but simplifies replica control Update-everywhere method speeds up data access but makes replica coordination more complex and expensive Master's Degree in Computer Engineering University of Minho
- 54. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Primary-copy approach introduces a single point of failure, but simplifies replica control Update-everywhere method speeds up data access but makes replica coordination more complex and expensive 1-copy serializability limits concurrency and thus scalability of the system Master's Degree in Computer Engineering University of Minho
- 55. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Primary-copy approach introduces a single point of failure, but simplifies replica control Update-everywhere method speeds up data access but makes replica coordination more complex and expensive 1-copy serializability limits concurrency and thus scalability of the system Concurrency control techniques and consistency criterion in lazy replication systems do not provide data freshness Master's Degree in Computer Engineering University of Minho
- 56. Survey Paper - UCE15 Conclusions Eager protocols are not appropriate for large scale systems Lazy protocols have better performance, but inconsistencies among copies may occur Primary-copy approach introduces a single point of failure, but simplifies replica control Update-everywhere method speeds up data access but makes replica coordination more complex and expensive 1-copy serializability limits concurrency and thus scalability of the system Concurrency control techniques and consistency criterion in lazy replication systems do not provide data freshness Some consistency techniques to improve data freshness emerged, but have a trade-off between consistency and performance Master's Degree in Computer Engineering University of Minho