DevOps · Flashcard
What is etcd?
- AA distributed, strongly consistent key-value store — used to hold critical configuration and coordination data
- BA distributed relational database — storing tables and rows queried with SQL across many nodes
- CA distributed message queue — buffering events between producers and consumers at high throughput
- DA distributed object cache — keeping hot data in memory to speed up reads from a slower backend
Why this is the answer
etcd is a strongly consistent, distributed key-value store used for config and coordination (it backs Kubernetes). It is not relational — there are no tables, rows or SQL; not a message queue — it stores state, not a stream of events; and not a cache — its data is the durable source of truth, not a disposable copy.
Official docs