Please enable JavaScript.

Coggle requires JavaScript to display documents.

Lecture 8: Consistency (Consistency (Replication: Solve problem of…

- - - - The system does not guarantee that subsequent accesses will return the updated value.
      - A number of conditions need to be met before the value will be returned.
      - Inconsistency window: The period between the update and the moment when it is guaranteed that any observer will always see the updated value.
    - - DNS
  - - - appear to client as as originate from single instance.
    - - every request received by a none-failing node result.
- - - - Best performance on connectivity, available bandwidth, processing power
      - Smallest average distance in latency
      - Identify autonomous region where most replicas are located
      - busiest replica need to update
    - - Permanent replica: processes/nodes require replica on site
      - Server-initiated:processes that dynamically host replica on demand
      - Client initiated : processes provides client cache upon request