# v3.5.33

Published articles for v3.5.33.

This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles.

## 【kube-apiserver】CRD / aggregation / 扩展边界：API 扩展停损线

DevFeed: [【kube-apiserver】CRD / aggregation / 扩展边界：API 扩展停损线](<https://devfeed.tech/articles/kube-apiserver-crd-aggregation-api-33969.md>)

Original publisher: [Read original article](<https://quant67.com/post/apiserver/13-extension-boundary/13-extension-boundary.html>)

Author: Liao Tonglang

Published: 2026-08-28T00:00:00Z

Content type: article

Language: zh

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

Topics: [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [API](<https://devfeed.tech/topics/api.md>), [etcd](<https://devfeed.tech/topics/etcd.md>), [Extension](<https://devfeed.tech/topics/extension.md>), [Server](<https://devfeed.tech/topics/server.md>)

Tags: [aggregation](<https://devfeed.tech/tags/aggregation.md>), [api](<https://devfeed.tech/tags/api.md>), [api-server](<https://devfeed.tech/tags/api-server.md>), [apiserver](<https://devfeed.tech/tags/apiserver.md>), [apiservice](<https://devfeed.tech/tags/apiservice.md>), [authorization](<https://devfeed.tech/tags/authorization.md>), [crd](<https://devfeed.tech/tags/crd.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [encryption](<https://devfeed.tech/tags/encryption.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [extension](<https://devfeed.tech/tags/extension.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [v1](<https://devfeed.tech/tags/v1.md>), [v1-30-3](<https://devfeed.tech/tags/v1-30-3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [webhook](<https://devfeed.tech/tags/webhook.md>)

### AI overview

This article explains the boundary between Kubernetes CRD and Aggregated API extension paths in kube-apiserver. CRD requests remain within the apiserver and use its storage and admission paths, while Aggregated API requests are proxied to an external Extension Server. The two paths have different failure modes and troubleshooting points, although both can appear as 503 errors or timeouts.

### Source excerpt

厘清 CRD v1 与 Aggregated API 两条扩展路径在 kube-apiserver 中的存储与请求分界：CRD 对象存 etcd、conversion webhook 失败如何体现在 Storage 轴，APIService 则把请求转发到外部 Extension Server 可引发 503。明确 scheduler/controller/kubelet 为扩展停损线之外的数据面与控制循环。

## 【etcd】MVCC 数据模型：Revision、keyIndex 与 generation

DevFeed: [【etcd】MVCC 数据模型：Revision、keyIndex 与 generation](<https://devfeed.tech/articles/etcd-mvcc-revision-keyindex-generation-33986.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/04-mvcc-model/04-mvcc-model.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [compaction](<https://devfeed.tech/tags/compaction.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [generation](<https://devfeed.tech/tags/generation.md>), [keyindex](<https://devfeed.tech/tags/keyindex.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [raft](<https://devfeed.tech/tags/raft.md>), [revision](<https://devfeed.tech/tags/revision.md>), [treeindex](<https://devfeed.tech/tags/treeindex.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This article analyzes etcd v3.5.33's MVCC data model through three concepts: globally ordered revisions, keyIndex generations that track key lifecycles, and the division of responsibilities between the in-memory treeIndex and the bbolt backend. It explains how these structures support historical Watch replay, transaction comparisons, compaction, and Kubernetes resourceVersion semantics, while distinguishing etcd revisions from Raft indexes.

### Source excerpt

拆解 etcd v3.5.33 的 Revision (main, sub) 全序、keyIndex/generation 生命周期与 treeIndex 分工；简要对照 v2 平面键空间，交代 MVCC 与 Watch/compaction 的语义基础。

## 【etcd】写入路径深读：Txn、mod revision 与 quota/alarm

DevFeed: [【etcd】写入路径深读：Txn、mod revision 与 quota/alarm](<https://devfeed.tech/articles/etcd-txn-mod-revision-quota-alarm-33989.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/07-write-path/07-write-path.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>), [Back end](<https://devfeed.tech/topics/backend.md>), [Raft](<https://devfeed.tech/topics/raft.md>), [Remote Procedure Call (RPC)](<https://devfeed.tech/topics/rpc.md>), [maintenance](<https://devfeed.tech/topics/maintenance.md>)

Tags: [alarm](<https://devfeed.tech/tags/alarm.md>), [apiserver](<https://devfeed.tech/tags/apiserver.md>), [applied-index](<https://devfeed.tech/tags/applied-index.md>), [apply](<https://devfeed.tech/tags/apply.md>), [batch](<https://devfeed.tech/tags/batch.md>), [bbolt](<https://devfeed.tech/tags/bbolt.md>), [committed-index](<https://devfeed.tech/tags/committed-index.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [defrag](<https://devfeed.tech/tags/defrag.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [errcompacted](<https://devfeed.tech/tags/errcompacted.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [follower](<https://devfeed.tech/tags/follower.md>), [k8s](<https://devfeed.tech/tags/k8s.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [mod-revision](<https://devfeed.tech/tags/mod-revision.md>), [nospace](<https://devfeed.tech/tags/nospace.md>), [quota](<https://devfeed.tech/tags/quota.md>), [revision](<https://devfeed.tech/tags/revision.md>), [txn](<https://devfeed.tech/tags/txn.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>)

### AI overview

This tutorial explains the etcd v3.5.33 write path from gRPC requests through Raft proposal, quota checks, MVCC apply, and ModRevision assignment. It also describes proposal backpressure, backend quota accounting, and how a NOSPACE alarm blocks writes while reads, deletes, and maintenance operations can continue.

### Source excerpt

走读 etcd v3.5.33 写入路径：raftRequest 背压、Txn compare/mod 与 ModRevision 分配、backend quota 与 NOSPACE alarm 如何把集群推入只读。

## 【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。

## 【etcd】WAL 与快照：预写日志、crash recovery 与 commit vs applied

DevFeed: [【etcd】WAL 与快照：预写日志、crash recovery 与 commit vs applied](<https://devfeed.tech/articles/etcd-wal-crash-recovery-commit-vs-applied-33985.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/03-wal-snapshot/03-wal-snapshot.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [applied-index](<https://devfeed.tech/tags/applied-index.md>), [committed-index](<https://devfeed.tech/tags/committed-index.md>), [crash-recovery](<https://devfeed.tech/tags/crash-recovery.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [latency](<https://devfeed.tech/tags/latency.md>), [persistence](<https://devfeed.tech/tags/persistence.md>), [safety](<https://devfeed.tech/tags/safety.md>), [snapshot](<https://devfeed.tech/tags/snapshot.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [wal](<https://devfeed.tech/tags/wal.md>)

### AI overview

This tutorial explains how etcd v3.5.33 uses WAL segments and Raft snapshots for persistence, log compaction, and crash recovery. It also describes how committed and applied indexes can diverge, causing Watch delays or extended not-ready periods even when Raft replication appears healthy.

### Source excerpt

拆解 etcd v3.5.33 的 WAL 段文件、Raft snapshot 触发与重启 recovery 顺序；钉清 committed index 与 applied index 分叉对排障与 K8s 控制面的含义。

## 【etcd】生产全景：缺口、五轴坐标系与 16 篇路线

DevFeed: [【etcd】生产全景：缺口、五轴坐标系与 16 篇路线](<https://devfeed.tech/articles/etcd-16-33983.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/01-production-overview/01-production-overview.html>)

Author: Liao Tonglang

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

Content type: article

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>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [control-plane](<https://devfeed.tech/tags/control-plane.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lease](<https://devfeed.tech/tags/lease.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [overview](<https://devfeed.tech/tags/overview.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>), [wal](<https://devfeed.tech/tags/wal.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This article positions an etcd production series by identifying gaps in existing coverage and defining five troubleshooting axes spanning Raft consensus, WAL persistence and recovery, MVCC storage and capacity, Watch behavior, and Lease handling. It anchors the series to etcd v3.5.33 and points to Kubernetes control-plane coupling and a 16-article reading route.

### Source excerpt

相对 distributed/50、39、13 钉清 etcd 生产内核缺口；定义 Raft/WAL/MVCC/Watch/Lease 五轴排障坐标系，给出 16 篇阅读路线与 K8s 控制面耦合指针。版本锚定 v3.5.33。

## 【etcd】Lease 与 KeepAlive：TTL、checkpoint 与 Leader 切换

DevFeed: [【etcd】Lease 与 KeepAlive：TTL、checkpoint 与 Leader 切换](<https://devfeed.tech/articles/etcd-lease-keepalive-ttl-checkpoint-leader-33992.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/10-lease/10-lease.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [Remote Procedure Call (RPC)](<https://devfeed.tech/topics/rpc.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [checkpoint](<https://devfeed.tech/tags/checkpoint.md>), [client](<https://devfeed.tech/tags/client.md>), [concurrency](<https://devfeed.tech/tags/concurrency.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [follower](<https://devfeed.tech/tags/follower.md>), [k8s](<https://devfeed.tech/tags/k8s.md>), [keepalive](<https://devfeed.tech/tags/keepalive.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lease](<https://devfeed.tech/tags/lease.md>), [lessor](<https://devfeed.tech/tags/lessor.md>), [primary](<https://devfeed.tech/tags/primary.md>), [raft](<https://devfeed.tech/tags/raft.md>), [ttl](<https://devfeed.tech/tags/ttl.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This article explains etcd v3.5.33 lease behavior, focusing on the lessor's primary, demote, and promote roles, the KeepAlive renewal path that normally bypasses Raft, lease checkpointing, and TTL changes during leader transitions. It also discusses implications for Kubernetes Node Leases and distributed locks.

### Source excerpt

钉 etcd v3.5.33 lessor 的 primary/demote/promote、KeepAlive 不经 Raft 的 Renew 路径、LeaseCheckpoint 与 Promote 时 TTL 展期，以及 Leader 切换对 Node Lease 的排障落格。

## 【etcd】运维与升级：member change、backup/restore 与 3.5-\>3.6/3.7 门

DevFeed: [【etcd】运维与升级：member change、backup/restore 与 3.5-\>3.6/3.7 门](<https://devfeed.tech/articles/etcd-member-change-backup-restore-3-5-3-6-3-7-33996.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/14-ops-upgrade/14-ops-upgrade.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>), [upgrade](<https://devfeed.tech/topics/upgrade.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [migration](<https://devfeed.tech/topics/migration.md>)

Tags: [backup](<https://devfeed.tech/tags/backup.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [learner](<https://devfeed.tech/tags/learner.md>), [member-change](<https://devfeed.tech/tags/member-change.md>), [migration](<https://devfeed.tech/tags/migration.md>), [operations](<https://devfeed.tech/tags/operations.md>), [raft](<https://devfeed.tech/tags/raft.md>), [recovery](<https://devfeed.tech/tags/recovery.md>), [restore](<https://devfeed.tech/tags/restore.md>), [snapshot](<https://devfeed.tech/tags/snapshot.md>), [upgrade](<https://devfeed.tech/tags/upgrade.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [v3-6](<https://devfeed.tech/tags/v3-6.md>), [v3-7](<https://devfeed.tech/tags/v3-7.md>)

### AI overview

A Chinese-language operational guide to etcd v3.5.33 covering member replacement and learner promotion, live snapshot backup and restore, Kubernetes control-plane recovery, patch upgrades, and documented upgrade gates from etcd 3.5 to 3.6 and 3.7.

### Source excerpt

member add/remove/replace 与 learner promote 检查单；snapshot backup/restore 及 K8s 语境 revision bump；3.5.33 补丁线与 3.6/3.7 官方升级门禁项，不超前写未钉 tag 能力。

## 【etcd】Watch 机制：watchableStore、synced/unsynced 与 ErrCompacted

DevFeed: [【etcd】Watch 机制：watchableStore、synced/unsynced 与 ErrCompacted](<https://devfeed.tech/articles/etcd-watch-watchablestore-synced-unsynced-errcompacted-33991.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/09-watch/09-watch.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Remote Procedure Call (RPC)](<https://devfeed.tech/topics/rpc.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [apiserver](<https://devfeed.tech/tags/apiserver.md>), [apply](<https://devfeed.tech/tags/apply.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [errcompacted](<https://devfeed.tech/tags/errcompacted.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [io](<https://devfeed.tech/tags/io.md>), [k8s](<https://devfeed.tech/tags/k8s.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lag](<https://devfeed.tech/tags/lag.md>), [leader](<https://devfeed.tech/tags/leader.md>), [lease](<https://devfeed.tech/tags/lease.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [notify](<https://devfeed.tech/tags/notify.md>), [raft](<https://devfeed.tech/tags/raft.md>), [range](<https://devfeed.tech/tags/range.md>), [restore](<https://devfeed.tech/tags/restore.md>), [revision](<https://devfeed.tech/tags/revision.md>), [rpc](<https://devfeed.tech/tags/rpc.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [watch](<https://devfeed.tech/tags/watch.md>), [watchablestore](<https://devfeed.tech/tags/watchablestore.md>)

### AI overview

This article examines the etcd v3.5.33 watchableStore implementation, including synced and unsynced watcher groups, victims caused by backpressure, Apply-time notification, historical synchronization, and the ErrCompacted client resynchronization boundary. It also discusses event ordering, follower watch progress, and interactions with Kubernetes apiserver watch caches.

### Source excerpt

钉 etcd v3.5.33 watchableStore 的 synced/unsynced/victims 三分法、Apply 后 notify 与历史追赶 syncWatchersLoop，以及 CompactRevision 触发 ErrCompacted 时的客户端重同步边界。

## 【etcd】单 Raft 组与服务器角色：Leader、Follower、Learner 与 request 路由

DevFeed: [【etcd】单 Raft 组与服务器角色：Leader、Follower、Learner 与 request 路由](<https://devfeed.tech/articles/etcd-raft-leader-follower-learner-request-33984.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/02-single-raft/02-single-raft.html>)

Author: Liao Tonglang

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

Content type: article

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>), [Raft](<https://devfeed.tech/topics/raft.md>), [gRPC](<https://devfeed.tech/topics/grpc.md>)

Tags: [apiserver](<https://devfeed.tech/tags/apiserver.md>), [apply](<https://devfeed.tech/tags/apply.md>), [atomic](<https://devfeed.tech/tags/atomic.md>), [commit](<https://devfeed.tech/tags/commit.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [etcdserver](<https://devfeed.tech/tags/etcdserver.md>), [follower](<https://devfeed.tech/tags/follower.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [leader](<https://devfeed.tech/tags/leader.md>), [learner](<https://devfeed.tech/tags/learner.md>), [linearizable](<https://devfeed.tech/tags/linearizable.md>), [raft](<https://devfeed.tech/tags/raft.md>), [request](<https://devfeed.tech/tags/request.md>), [single-raft-group](<https://devfeed.tech/tags/single-raft-group.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [wal](<https://devfeed.tech/tags/wal.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This article explains how etcd v3.5.33 embeds a single Raft group, separates EtcdServer responsibilities from the Raft library, and routes requests across Leader, Follower, and Learner roles. It covers gRPC write forwarding, linearizable and serializable reads, and the handling of watch, lease, and mutating requests.

### Source excerpt

钉清 etcd v3.5.33 单 Raft 组拓扑、EtcdServer 与 go.etcd.io/raft/v3 边界、Leader/Follower/Learner 角色及 gRPC 写读路由；与 distributed/13 分工。

## 【etcd】Txn 与并发语义：compare/mod 与 Jepsen 边界

DevFeed: [【etcd】Txn 与并发语义：compare/mod 与 Jepsen 边界](<https://devfeed.tech/articles/etcd-txn-compare-mod-jepsen-33993.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/11-txn-semantics/11-txn-semantics.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>), [version](<https://devfeed.tech/topics/version.md>), [Raft](<https://devfeed.tech/topics/raft.md>), [API](<https://devfeed.tech/topics/api.md>)

Tags: [bug](<https://devfeed.tech/tags/bug.md>), [compare](<https://devfeed.tech/tags/compare.md>), [concurrency](<https://devfeed.tech/tags/concurrency.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [jepsen](<https://devfeed.tech/tags/jepsen.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [raft](<https://devfeed.tech/tags/raft.md>), [serializable](<https://devfeed.tech/tags/serializable.md>), [txn](<https://devfeed.tech/tags/txn.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [version](<https://devfeed.tech/tags/version.md>)

### AI overview

This article examines etcd v3.5.33 transaction semantics, including compare operations, nested transactions, MVCC visibility, ReadIndex behavior, and Raft-based atomic application. It distinguishes the design goals of the KV transaction path from the Lease session-lock path and carefully limits Jepsen evidence to etcd 3.4.3 rather than claiming an independent 3.5.33 rerun.

### Source excerpt

钉 etcd v3.5.33 Txn 的 compareToPath、MOD/CREATE/VERSION 比较与写 Txn 的 Raft 单槽 apply，并对照 Jepsen 3.4.3 的 strict-serializable 与 Lease 锁不安全子集。

## 【etcd】选型收束与开放问题：排除树与系列边界关闭

DevFeed: [【etcd】选型收束与开放问题：排除树与系列边界关闭](<https://devfeed.tech/articles/etcd-33998.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/16-selection/16-selection.html>)

Author: Liao Tonglang

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

Content type: article

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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [apiserver](<https://devfeed.tech/tags/apiserver.md>), [backup](<https://devfeed.tech/tags/backup.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [exclusion-tree](<https://devfeed.tech/tags/exclusion-tree.md>), [foundationdb](<https://devfeed.tech/tags/foundationdb.md>), [guide](<https://devfeed.tech/tags/guide.md>), [k8s](<https://devfeed.tech/tags/k8s.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lease](<https://devfeed.tech/tags/lease.md>), [open-questions](<https://devfeed.tech/tags/open-questions.md>), [raft](<https://devfeed.tech/tags/raft.md>), [selection](<https://devfeed.tech/tags/selection.md>), [tikv](<https://devfeed.tech/tags/tikv.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [zookeeper](<https://devfeed.tech/tags/zookeeper.md>)

### AI overview

This concluding article presents a mechanism-based decision tree for deciding when to retain etcd and when to migrate to TiKV or FoundationDB. It defines etcd's fit for small data sets with Watch and Lease dependencies, identifies disqualifying conditions such as quota pressure, sharding needs, cross-key transactions, Watch backpressure, and insufficient operational capacity, and clarifies the boundaries between related article series.

### Source excerpt

用机制排除树收束何时该留 etcd、何时迁 TiKV/FDB/ZK；回收 distributed/39、tikv-htap/18、foundationdb/18 的 etcd 叶；列出 Watch 背压、Lease+fencing、quota 迁移等开放问题；以 ADR 语言关闭续作边界。

## 【etcd】读路径与一致性：ReadIndex、Serializable 与 Lease read

DevFeed: [【etcd】读路径与一致性：ReadIndex、Serializable 与 Lease read](<https://devfeed.tech/articles/etcd-readindex-serializable-lease-read-33990.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/08-read-consistency/08-read-consistency.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [consensus algorithm](<https://devfeed.tech/topics/consensus-algorithm.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [consistency](<https://devfeed.tech/tags/consistency.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [follower](<https://devfeed.tech/tags/follower.md>), [k8s](<https://devfeed.tech/tags/k8s.md>), [keepalive](<https://devfeed.tech/tags/keepalive.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lease](<https://devfeed.tech/tags/lease.md>), [linearizable](<https://devfeed.tech/tags/linearizable.md>), [raft](<https://devfeed.tech/tags/raft.md>), [readindex](<https://devfeed.tech/tags/readindex.md>), [resourceversion](<https://devfeed.tech/tags/resourceversion.md>), [revision](<https://devfeed.tech/tags/revision.md>), [serializable](<https://devfeed.tech/tags/serializable.md>), [ttl](<https://devfeed.tech/tags/ttl.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>)

### AI overview

This tutorial explains read consistency in etcd v3.5.33. It distinguishes default linearizable reads using ReadIndex, local Serializable reads that may be stale on followers, and Lease RPC reads handled by the leader outside the Raft log. It also discusses leader changes, apply-index waiting, follower forwarding, MVCC history reads, and implications for Kubernetes apiserver clients.

### Source excerpt

分列 etcd v3.5.33 三种读语义：默认线性一致读的 ReadIndex 循环、Serializable 本地读、Raft ReadOnlyLeaseBased 与不经 Raft 的 Lease 路径；follower 读风险与 K8s 期望。

## 【etcd】排障五轴：Raft/WAL/MVCC/Watch/Lease 口令表

DevFeed: [【etcd】排障五轴：Raft/WAL/MVCC/Watch/Lease 口令表](<https://devfeed.tech/articles/etcd-raft-wal-mvcc-watch-lease-33997.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/15-troubleshoot/15-troubleshoot.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>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [apiserver](<https://devfeed.tech/tags/apiserver.md>), [applied-index](<https://devfeed.tech/tags/applied-index.md>), [apply](<https://devfeed.tech/tags/apply.md>), [committed-index](<https://devfeed.tech/tags/committed-index.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [errcompacted](<https://devfeed.tech/tags/errcompacted.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [five-axes](<https://devfeed.tech/tags/five-axes.md>), [incident](<https://devfeed.tech/tags/incident.md>), [keepalive](<https://devfeed.tech/tags/keepalive.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lag](<https://devfeed.tech/tags/lag.md>), [lease](<https://devfeed.tech/tags/lease.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [node-lease](<https://devfeed.tech/tags/node-lease.md>), [raft](<https://devfeed.tech/tags/raft.md>), [restore](<https://devfeed.tech/tags/restore.md>), [troubleshooting](<https://devfeed.tech/tags/troubleshooting.md>), [ttl](<https://devfeed.tech/tags/ttl.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [wal](<https://devfeed.tech/tags/wal.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This troubleshooting article organizes etcd failures into five diagnostic axes: Raft consensus, WAL persistence and recovery, MVCC storage and capacity, Watch client synchronization, and Lease TTL semantics. It maps symptoms to axes, explains relevant etcdctl health and status fields, and notes Kubernetes control-plane relationships, including apiserver and Node Lease behavior. The article is anchored to etcd v3.5.33.

### Source excerpt

按 Raft、WAL、MVCC、Watch、Lease 五轴做症状否证；解释 etcdctl endpoint status/health 字段语义；并对照 K8s 控制面 apiserver 超时与 Node Lease 漂移。

## 【etcd】Kubernetes 控制面耦合：apiserver、resourceVersion 与 Node Lease

DevFeed: [【etcd】Kubernetes 控制面耦合：apiserver、resourceVersion 与 Node Lease](<https://devfeed.tech/articles/etcd-kubernetes-apiserver-resourceversion-node-lease-33995.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/13-k8s-coupling/13-k8s-coupling.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>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [API](<https://devfeed.tech/topics/api.md>), [Cache](<https://devfeed.tech/topics/cache.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [apiserver](<https://devfeed.tech/tags/apiserver.md>), [cache](<https://devfeed.tech/tags/cache.md>), [control-plane](<https://devfeed.tech/tags/control-plane.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lease](<https://devfeed.tech/tags/lease.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [node-lease](<https://devfeed.tech/tags/node-lease.md>), [raft](<https://devfeed.tech/tags/raft.md>), [resourceversion](<https://devfeed.tech/tags/resourceversion.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [watch](<https://devfeed.tech/tags/watch.md>), [watch-cache](<https://devfeed.tech/tags/watch-cache.md>)

### AI overview

This article explains how Kubernetes control-plane components interact with etcd. It covers the kube-apiserver boundary, the mapping of resourceVersion to etcd mod revision, Node Lease storage, watch cache behavior, and how compaction, caching, and event sharding affect troubleshooting and etcd load.

### Source excerpt

钉 kube-apiserver 与 etcd 的分层边界；resourceVersion 如何映射 Revision MVCC；Node Lease 如何落在 Lease 轴；以及 apiserver 超时应如何分列到 Raft/Watch/Quota 五轴。

## 【etcd】Compaction、Defrag 与容量：quota、alarm 与 SLO

DevFeed: [【etcd】Compaction、Defrag 与容量：quota、alarm 与 SLO](<https://devfeed.tech/articles/etcd-compaction-defrag-quota-alarm-slo-33994.md>)

Original publisher: [Read original article](<https://quant67.com/post/etcd/12-compaction-quota/12-compaction-quota.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>), [Raft](<https://devfeed.tech/topics/raft.md>), [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>)

Tags: [alarm](<https://devfeed.tech/tags/alarm.md>), [bbolt](<https://devfeed.tech/tags/bbolt.md>), [benchmark](<https://devfeed.tech/tags/benchmark.md>), [compaction](<https://devfeed.tech/tags/compaction.md>), [defrag](<https://devfeed.tech/tags/defrag.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [errcompacted](<https://devfeed.tech/tags/errcompacted.md>), [etcd](<https://devfeed.tech/tags/etcd.md>), [follower](<https://devfeed.tech/tags/follower.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [lag](<https://devfeed.tech/tags/lag.md>), [leader](<https://devfeed.tech/tags/leader.md>), [mvcc](<https://devfeed.tech/tags/mvcc.md>), [nospace](<https://devfeed.tech/tags/nospace.md>), [performance](<https://devfeed.tech/tags/performance.md>), [quota](<https://devfeed.tech/tags/quota.md>), [raft](<https://devfeed.tech/tags/raft.md>), [resourceversion](<https://devfeed.tech/tags/resourceversion.md>), [v3](<https://devfeed.tech/tags/v3.md>), [v3-5](<https://devfeed.tech/tags/v3-5.md>), [v3-5-33](<https://devfeed.tech/tags/v3-5-33.md>), [watch](<https://devfeed.tech/tags/watch.md>)

### AI overview

This technical article explains how etcd v3.5.33 compaction, defragmentation, quota handling, and the NOSPACE alarm interact. It distinguishes revision-history removal from bbolt file reclamation, describes periodic and revision-based auto-compaction, and connects retention, quota, defrag pauses, and Watch or Kubernetes control-plane behavior to operational SLOs.

### Source excerpt

钉 etcd v3.5.33 MVCC compaction 与 bbolt defrag 的分工、auto-compaction 保留窗口、quota-backend-bytes 与 NOSPACE alarm 写入门，以及 ErrCompacted 如何写进 Watch SLO。