Sloppy Quorum

1. Overview

Definition of Sloppy Quorum:
- A system design pattern commonly used in distributed systems.
- It allows for read or write operations to succeed even when some nodes in the cluster are down or unreachable.
Key Characteristics:
- Offers high availability and fault tolerance.
- Data replication across multiple nodes enhances resiliency.
- Reduced consistency guarantees in exchange for availability.
The Role of Quorum:
- A traditional quorum requires a majority of nodes to respond for an operation to succeed.
- Sloppy quorum relaxes this criterion, allowing operations to proceed with responses from fewer nodes or even from nodes that are not part of the intended quorum.
Use Cases:
- Often implemented in systems where speed and uptime are prioritized over strict consistency, such as in NoSQL databases.
- Can be beneficial in managing transient failures or network partitions.
Trade-offs:
- While it improves availability, it may lead to stale reads or temporary inconsistencies in the system.
- Use requires careful consideration of the acceptable level of inconsistency for the application in question.