# Consistency Consistency in the context of distributed systems revolve around two things, safety and liveness. ## Eventual consistency Makes promises about liveness only. ## Strong eventual consistency Makes promises about liveness and safety ## Liveness The property that eventually something good will happen. For example saying that a system will return a result to every API call is a liveness property. ## Safety The property states that nothing bad will ever happen. For example never returning a wrong value or electing two leaders. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://isubasinghe.gitbook.io/isithas-wiki/computer_science/distributed_systems/consistency.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.