Edge KV is a key-value pair storage service available at points of presence (POPs). Data written to Edge KV is quickly synchronized globally across POPs. Edge Routine (ER) allows for fast reading of Edge KV data from the same POP. Use Edge KV with ER to deploy lightweight Blockchain as a Service (BaaS) and API gateway services.
How it works
When you write key-value pairs in the ESA console or by calling an API, the data is first stored in the KV storage of the central POP, not directly at the edge POPs. Shortly after being stored, ESA clears the corresponding "dirty data" from the KV storage at the edge POPs to ensure data accuracy.
When a client initiates a request, the key-value pair is retrieved from the nearest edge POP, which speeds up data access. However, newly written data may not be immediately available at the edge POPs, leading to potential cache misses.
In such cases, ESA proactively reads the data from the central POP and cache it at the edge POPs. Subsequent requests will hit the cache. This mechanism makes the first access to newly written data slower, but subsequent accesses faster.
Given this working principle, Edge KV is ideal for scenarios that require low-frequency writes and high-frequency reads, along with global consistency of stored data.
Terms
NameSpace
A namespace is a database for managing key-value pairs, distinguished by a globally unique name within your account. After you create a namespace, you can add key-value pairs to it.
KV (Key-Value)
Each key-value pair belongs to a namespace. Before you read a key-value pair, you need to specify a namespace.
