# 【etcd】bbolt 后端：mmap、batch 与单写者约束

DevFeed: [【etcd】bbolt 后端：mmap、batch 与单写者约束](<https://devfeed.tech/articles/etcd-bbolt-mmap-batch-33987.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/05-bbolt-backend/05-bbolt-backend.html>)

Author: Liao Tonglang

Published: 2026-08-26T00:00:00Z

Content type: tutorial

Language: zh

Sources: [土法炼钢 - 系统与基础设施](<https://devfeed.tech/sources/source-4.md>)

Topics: [etcd](<https://devfeed.tech/topics/etcd.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [Raft](<https://devfeed.tech/topics/raft.md>)

Tags: [apply](<https://devfeed.tech/tags/apply.md>), [backend](<https://devfeed.tech/tags/backend.md>), [batch](<https://devfeed.tech/tags/batch.md>), [bbolt](<https://devfeed.tech/tags/bbolt.md>), [commit](<https://devfeed.tech/tags/commit.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [mmap](<https://devfeed.tech/tags/mmap.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [raft](<https://devfeed.tech/tags/raft.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>)

## AI overview

This article explains how etcd v3.5.33 maps its MVCC storage model onto the bbolt backend. It covers bucket layout, mmap behavior, buffered batch commits, read and write transaction concurrency, and how bbolt's single-writer constraint shapes apply and linearizable reads.

## Source excerpt

钉清 etcd v3.5.33 的 bbolt 后端：bucket 布局、mmap 预映射、100ms/10000 条 batch commit、ConcurrentReadTx 与单写者如何约束 MVCC 读写并发。