pushing the cap

CAP TheoremProposed Approach

Pushing the CAPStrategies for Consistency and Availability

Muhammad Anis uddin Nasir

FIB UPC

April 12, 2012

Muhammad Anis uddin Nasir Pushing the CAP Strategies for Consistency and Availability


1 CAP Theorem

2 Proposed Approach



CAP Theorem



WHY 2 OF 3 IS MISLEADING



CAP Theorem

Partitions are rare, there is little reason to forfeit C or A whenthe system is not partitioned

C and A can be variable throughout the life of the System

CAP is continuous



1 CAP Theorem

2 Proposed Approach



Proposed Approach



Partition Recovery

The state on both sides must become consistent

There must be compensation for the mistakes made duringpartition mode



Partition Recovery- Way out

Starting from the state at the time of the partition

Rolling Back

Constrain the use of certain operations during partitioning

Delaying risky operations

CRDT (commutative replicated data types)

Compensating mistakes



Conslusion

Consistency or Availability should not be blindly sacrificed

Careful management of invariants during partitions

Different solutions(CRDTs can be very useful for optimization)

Best solutions depends on details about the service’sinvariants and operations.



Pushing the CAPStrategies for Consistency and Availability

Muhammad Anis uddin Nasir

FIB UPC

April 12, 2012


pushing the cap

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