What is causal consistency model?

What is causal consistency model?

What is causal consistency model?

Causal consistency captures the notion that causally-related operations should appear in the same order on all processes—though processes may disagree about the order of causally independent operations.

What is causal consistency in distributed systems?

Introduction. Causal consistency [1] is one of the consistency criteria that can be used on distributed databases as consistency criteria. Distributed database provides causal consistency if read and write operations that are causally related are seen by every node of the distributed system in the same order.

What is causal consistency in nosql?

Causal Consistency. If some process updates a given object, all the processes that acknowledge the update on this object will consider the updated value. However, if some other process does not acknowledge the write operation, they will follow the eventual consistency model [16].

What is causal consistency MongoDB?

That is, causally consistent client sessions can only guarantee causal consistency for: Read operations with “majority” read concern; i.e. the read operations that return data that has been acknowledged by a majority of the replica set members and is durable.

What are the different types of consistency?

Types

  • Strict consistency. Strict consistency is the strongest consistency model.
  • Sequential consistency. The sequential consistency model was proposed by Lamport(1979).
  • Causal consistency.
  • Processor consistency.
  • Pipelined RAM consistency, or FIFO consistency.
  • Cache consistency.
  • Slow consistency.
  • Release consistency.

Is MongoDB eventually consistent?

MongoDB is consistent by default: reads and writes are issued to the primary member of a replica set. Applications can optionally read from secondary replicas, where data is eventually consistent by default.

Is MongoDB strong consistency?

By default, MongoDB is a strongly consistent system. Once a write completes, any subsequent read will return the most recent value. Cassandra, by default, is an eventually consistent system. Once a write completes, the latest data eventually becomes available provided no subsequent changes are made.

What do you mean by FIFO consistency?

FIFO Consistency (1) Writes done by a single process are seen by all other processes in the order in which they were issued, but writes from different processes may be seen in a different order by different processes. Two or more writes from the same process must be seen in order.

What is meant by cache consistency?

In computer architecture, cache coherence is the uniformity of shared resource data that ends up stored in multiple local caches. Cache coherence is intended to manage such conflicts by maintaining a coherent view of the data values in multiple caches.

Why is eventual consistency used?

Eventual consistency is a consistency model used in distributed computing to achieve high availability that informally guarantees that, if no new updates are made to a given data item, eventually all accesses to that item will return the last updated value.