Etcd data inconsistent Repeated get-requests of a key will return different (versions of) values depending on You signed in with another tab or window. The following shows the k8s leader election key inside the etcd db. The write ahead log and snapshot files are used during member operation and to recover after a restart. 16. 10. The client may get different values against the same key from different endpoints. Symptoms: The etcd pods failed Aug 19, 2024 · Data model; etcd v3 authentication design; etcd versus other key-value stores the inconsistent state can be prolonged and it might result in counter-intuitive Sep 29, 2022 · Recent v3. After removing the member, delete its data. etcd, m2. Both checks however have a flaw, they depend on HashKV grpc method, which might fail causing the check to pass. Data inconsistency in etcd cluster nodes. It can be executed during etcd start via --experimental-initial-corrupt-check and periodically via --experimental-corrupt-check-time. Nov 21, 2022 · After recently discovered consistency problems in etcd-3. They work together to create the normal operating state where everything runs smoothly and your cluster meets expectations. etcd 快速开始 1. This new protocol provides an opportunity to iterate on and improve the v2 design. Nov 6, 2024 · The exact amount of nodes, pods, and other resources that 8GB can support depends on the specific use case and the size of the data stored in etcd. etcd pod failed to start due to inconsistent data. Data corruption detection can be done using: Initial check, enabled with --experimental-initial-corrupt-check flag. Oct 1, 2024 · Backup: Regularly back up etcd data. Judging which node etcd data is incorrect through the container status Jan 20, 2024 · This article mainly introduces the relevant knowledge of what to do with etcd3 data inconsistency. key total number is almost the same，but revision and events is far less than followers. It is quite important to have the experience to back up… Nov 21, 2022 · After recently discovered consistency problems in etcd-3. May 5, 2020 · “ etcd 作为 Kubernetes 集群的元数据存储，是被业界广泛使用的强一致性 KV 存储，但近日被挖掘出一个存在 3 年之久的数据不一致 bug——client 写入后无法在异常节点读取到数据，即数据丢失。本文介绍了我们是如何从问题分析、大胆猜测、严谨验证、排除、工程化复现，从 raft 到 boltdb Nov 11, 2022 · First, I would like to thank you for providing the fix regarding the Inconsistent Timestamps in ETCD logs. Reload to refresh your session. mvcc/backend: Fix corruption bug in defrag #11613 Jan 11, 2022 · Google 输入“etcd data inconsistent” 搜索发现，并不是只有我们遇到过该问题，之前也有其他人向 etcd 社区反馈过类似问题，只是苦于没有提供稳定的复现方式，最后都不了了之。 Dec 1, 2021 · Interesting. But if we upgrade between 2 versions of our microservice , this data inconsistency issue is seen. kubectl kubectl scale sts <etcd-sts> --replicas= 0 # delete the pvc for etcd-0, etcd-1, etcd-2 kubectl kubectl scale sts <etcd-sts> --replicas= 1 # restore the backup data I meet data inconsistency in 3. Hello, We use a kubernetes cluster with 3 or 2 etcds and we see that sometime one of the etcd member goes into the below issue: we see the issue that the etcd can't speak with his cluster members anymore. 9. But get 5 netmaster pods on the 1 bad node（we have deleted the 2 netmasterpods） A panic occurred during operation, it seems that the data is inconsistent after etcd restarting, no errors were detected at startup. Drawing from their Site Reliability Engineering (SRE) expertise, they fostered a culture of "blameless postmortems" within the etcd community—a Apr 26, 2020 · 作为一个21世纪的程序员，遇到这种诡异且暂时没头绪的问题，第一反应当然是先 Google 一下啦，毕竟不会 StackOverFlow 的程序员不是好运维!Google 输入“etcd data inconsistent” 搜索发现，并不是只有我们遇到过该问题，之前也有其他人向 etcd 社区反馈过类似问题 Inconsistent data in etcd #14083. Contribute to ahrtr/etcd-issues development by creating an account on GitHub. 0. Mar 4, 2016 · We are facing an data inconsistency issue in ETCD-3. A distributed, reliable key-value store for the most critical data of a distributed system Learn more Quickstart What is etcd? etcd is a strongly consistent, distributed key-value store that provides a reliable way to store data that needs to be accessed by a distributed system or cluster of machines. 5 issues has showed that etcd doesn't have a reliable way to protect users from data inconsistency. I hope this article how to do etcd3 data inconsistency can help you solve the problem. etcd, through its design and the Raft consensus algorithm, mitigates these issues by enforcing quorum rules. Best Practices for Managing etcd Database Size Mar 3, 2011 · We have our microservice named etcd-micro where we are using etcd for storing data. 169Z but, our required format is 2022-11-18T07:15:24. [0-5] data inconsistency issue for a case when etcd crashes during processing defragmentation operation Sep 28, 2020 · 搜索框输入“etcd data inconsistent” 搜索发现，并不是只有我们遇到过该问题，之前也有其他人向 etcd 社区反馈过类似问题，只是苦于没有提供稳定的复现方式，最后都不了了之。 本文介绍了我们是如何从问题分析、大胆猜测、严谨验证、排除、工程化复现，从 raft 到 boltdb，从源码定制再到 chaos monkey，一步步定位并解决 etcd 数据不一致 bug 的详细流程，并将解决方案提交给社区，移植到 etcd 3. It’s aware of what's the last applied WAL log index ("consistent_index"). 0 Configuration: 3 nodes, with 8 CPU and 16 MEM For one day our Kubernetes cluster is running okay, but suddenly I got data inconsistent from Grafana dashboard which I keep looking for the Nov 13, 2020 · 三年之久的 etcd 3 数据不一致 bug 分析，etcd作为Kubernetes集群的元数据存储，是被业界广泛使用的强一致性KV存储，但近日被挖掘出一个存在3年之久的数据不一致bug——client写入后无法在异常节点读取到数据，即数据丢失。 Feb 20, 2023 · "NoSuchKey" indicates the metadata and data files is inconsistent. " but the data file doesn't exist on minio. There is not panic log, such as range failed to find revision pair . Even with a slow mechanical disk or a virtualized network disk, such as Amazon’s EBS or Google’s PD, applying a request should normally take fewer than 50 milliseconds. we have investigated the ETCD logs and found there were some issue with auth revision. [0-5] data inconsistency issue for a case when etcd crashes during processing defragmentation operation Apr 7, 2022 · Fix the data inconsistency issue by moving the SetConsistentIndex into the transaction lock #13854 [3. 1 k8s cluster: v1. Already have an account? Sign in to comment. After upgrading to microservice with etcd 3. Aug 19, 2024 · Data model; etcd v3 authentication design; etcd versus other key-value stores the inconsistent state can be prolonged and it might result in counter-intuitive You can use df -h | grep etcd-wal to check the storage usage. From this we can say right that issue existed in 3. 4. 0 (3. 5. dev. gov Last modified by: Sviglin, Helena Created Date: 2/9/2021 7:40:20 AM Other titles: FDA Validator Rules Intro FDA Validator Rules v1. 11 #13503. In case of a catastrophic failure, you can restore the cluster’s state using the latest backup. As part of the process we discovered following issues: Issue 1: etcd v3. After some time, do a rollback. Having a . x which could be affected by a known issue in etcd v3. An etcd cluster automatically recovers from temporary failures (e. Configuration is stored in the write ahead log and includes: the local member ID, cluster ID, and initial cluster configuration. 171. Notice the renewTime value, which is inconsistent on only one of the three members of the quorum -- the etcd leader. Compacted revision hash, enabled with --experimental-compact-hash-check-enabled flag. x rollback> 3. Recovery: If an etcd node goes down, 1. You switched accounts on another tab or window. md Problems: Lack of adoption prevents early P0 action item proposed in https://github. Sep 8, 2024 · These scenarios can result in conflicts, inconsistencies, and data corruption. 11 node. In a linearizable system, all operations must appear to take place at a specific, atomic point in time between the invocation and completion of tha May 4, 2022 · What happened? After starting etcd with --force-new-cluster, removing the database files off the secondary nodes, and rejoining them to the cluster, the cluster is now in a split-brain state. Symptoms: The etcd pods failed we add debugging log and use simple chaos monkey tool to reproduce it. The following questions may arise due to this: What should I do until a fix has been delivered? Sep 17, 2023 · etcd has built in automated data corruption detection to prevent member state from diverging. It gracefully handles leader elections during network partitions and can tolerate machine Apr 9, 2022 · Why not reuse the v2 auth system? The v3 protocol uses gRPC as its transport instead of a RESTful interface like v2. We saw, revision are different on one the pod. 0 ~ 3. Original topic: pd无法启动，提示集群id不匹配 | username: 月明星稀 [TiDB Usage Environment] Production Environment [TiDB Version&hellip; Jan 3, 2025 · File name High level purpose. Seems it had been changed after the restart of pod and impacting the data inconsistency. Etcd. The background of the question is weird. It is at the heart of Kubernetes and is an integral part of its control-plane. 4 upgrade-> 3. The cluster’s ETCD setup had not been optimized for high availability and load distribution, leading to bottlenecks when multiple processes attempted to access the ETCD server You can use df -h | grep etcd-wal to check the storage usage. 13 node is different from that on the 10. You signed out in another tab or window. node A(3. As proposed in the postmortem from the incident, etcd maintainers have developed much more robust mechanism to detect data inconsistency that can be back-ported to previous release. 确保重启后重建的版本号不能小于已经compact的revision. 4。I have a three node etcd cluster, the problem will be happened occasionally when three node reboot at the same time. 5, etcd maintainers are investing in extensive testing of data consistency in different etcd crash modes. In cluster mode, there is also 10. https://tess-master-cbtkd-8128. *:4001, 87e6a178ab5a0f63, 3. Closed didihongsheng opened this issue May 31, 2022 · 2 comments Closed Inconsistent data in etcd #14083. etcd version: 3. com/etcd-io/etcd/blob/main/Documentation/postmortems/v3. 5] Fix the data inconsistency issue by adding a txPostLockHook into the backend #13908; Data inconsistency in etcd version 3. Jan 3, 2025 · File name High level purpose. Apr 27, 2021 · 第2部では、etcdのアーキテクチャと基本的なAPIを紹介し、etcdの基本的なデータ操作とetcdがどのように動作するかを説明しました。 第3部では、3つの典型的なetcdのシナリオと、これらのシナリオにおける分散システムの設計思想について説明しました。 Back up the data in this bucket and run the following commands. 0 in the title] In general the behavior you are describing might happen in: --consistency="s" serializable mode (that is NOT the default for etcdctl get), but should NOT happen in the --consistency="l" mode (the default ONE), where the Oct 2, 2024 · If only one member is inconsistent, just replace it. Red Hat has become aware of a potential data inconsistency issue present in etcd 3. There doesn’t seem to be a limit on key or value size, but by default, the Apr 11, 2024 · etcd is designed to withstand machine failures. 11 that time data inconsistency issue was not there and everything was working fine. 13. 0 through 4. Apr 7, 2023 · This system is crucial in preventing conflicting operations and data inconsistency. Impact Sep 11, 2024 · Upon inspecting the etcd data, I discovered that the original sync state values were inconsistent. Closed Sign up for free to join this conversation on GitHub. 5, I see the data inconsistent problem was fixed in pull/13908, but I still encounter the data inconsistent problem。 Mar 2, 2020 · etcd数据不一致bug案例分析; etcd数据不一致bug案例分析. Depending on when the last snapshot was taken, this could lead to inconsistency issues between the etcd database and cluster status. In the CHANGELOG-3. Kube State Metric sWatch Errors; Kube State Metrics List Errors; Kube State Metrics Sharding Mismatch Dec 15, 2017 · It was getting revisions with "atRev==0", which makes "available" from "keep" method always empty since "walk" on "keyIndex" only returns true. 4/3. 2. Jan 8, 2017 · I have one 4 members' cluster. 16 as well. Sep 13, 2022 · etcd is a key-value data store that holds all Kubernetes cluster data and state information. View the data stored in etcd by the problematic pod. 5 releases are affected, including 3. We need more usage Apr 21, 2022 · cc @ahrtr @spzala @ptabor Very drafty, if there are no obvious mistakes we can merge and iterate on it. If you see the following symptoms contact support: Run the command “/var/vcap/jobs/etcd/bin/etcdctl endpoint status -w json --cluster” on any control plane node to compare the revision between members. The operation method is simple and fast, and it is practical. hhs. 1 Sep 16, 2020 · 二进制方式安装的k8s集群，etcd集群有3个节点，某天有一台机器hang住了，无法远程ssh登陆，于是被管理员直接重启了，重启后发现k8s集群删除一个deployment应用，多次刷新一会有，一会没有，于是在3个节点上执行etcd命令去查询该数据，发现被重启的节点上仍存在删除的该应用的数据，于是判断etcd Google 输入“etcd data inconsistent” 搜索发现，并不是只有我们遇到过该问题，之前也有其他人向 etcd 社区反馈过类似问题，只是苦于没有提供稳定的复现方式，最后都不了了之。 Mar 4, 2018 · A 3 etcd cluster returned inconsistent data. 168. Sep 7, 2022 · etcdctl 直接查询了 etcd 集群状态和集群数据，返回结果显示 3 个节点状态都正常，且 RaftIndex 一致，观察 etcd 的日志也并未发现报错信息，唯一可疑的地方是 3 个节点的 dbsize 差别较大。 Apr 26, 2021 · A restore initializes a new member of a new cluster, with a fresh cluster configuration using etcd’s cluster configuration flags, but preserves the contents of the etcd keyspace. 11 and 3. , machine reboots) and tolerates up to (N-1)/2 permanent failures for a cluster of N members. . Add etcd --log-rotation-config-json flag which allows passthrough of JSON config to configure log rotation for a file output target. /member/snap/db: bbolt b+tree that stores all the applied data, membership authorization information & metadata. go:406] Alertmanager Members Inconsistent; etcd. The etcd stores a meta point to "files/insert_log/43911. If disk is full, refer to etcd write-ahead log (WAL) directory maintenance to purge the etcd WAL files. See this guide. What's the exact etcd version ? [edit: see 3. May 13, 2022 · P0 action item proposed in https://github. The editor shows you the operation process through an actual case. etcd cluster: created and running with v3. 11, not shown here. This is where you can really help. If all members are inconsistent, things get trickier. I'm a new user of etcd，and I setup the etcd's cluster by docker on the same machine. etcd is very hard to troubleshooting data inconsistency due to lack of log. Assignees Jan 4, 2023 · There is a known issue that etcd might run into data inconsistency issue if it crashes in the middle of an online defragmentation operation using etcdctl or clientv3 API. Jun 10, 2020 · Etcd’s data model supports key/value pairs, where both the key and value are represented as binary arrays or strings. 722+02:00 Mar 31, 2020 · After investigating, we believe the source of this problem to be data inconsistency between etcd, akin to "split brain". x Apr 27, 2021 · Data Directory Lifecycle When first started, etcd stores its configuration into a data directory specified by the data-dir configuration parameter. [0-5] data inconsistency issue for a case when etcd crashes during processing defragmentation operation Apr 26, 2021 · Why not reuse the v2 auth system? The v3 protocol uses gRPC as its transport instead of a RESTful interface like v2. *. 22 I found a data inconsi Apr 6, 2022 · There may be no clear symptoms of data inconsistencies, but your clusters may be affected. Apr 25, 2018 · We have a 3 node etcd cluster that we used as a backend for a kubernetes cluster and on one of the nodes the data is inconsistent with the others: Member list etcdctl member list 76c74df0105143e4, started, etcd1, https://172. The Kubernetes architecture relies on these components being continually available. Apr 26, 2020 · etcd 是一个强一致性的分布式 KV 存储，所谓强一致性，简单来说就是一个写操作成功后，从任何一个节点读出来的数据都是最新值，而不会出现写数据成功后读不出来或者读到旧数据的情况。 Jun 13, 2024 · Data Consistency: Early Detection and Swift Action: Google engineers led efforts to identify and resolve data inconsistency issues in etcd, advocating for public awareness and mitigation strategies. the leader's revsion is a lot behind, and memory is much smaller than followers. 15, 11 GB, true, 2868, 59480228 https://tess-m I run 3 etcd server instances and I frequently observe that the data bases get out of sync without the etcd cluster detecting a cluster health issue. etcd 是什么？ Etcd 是 CoreOS 基于 Raft 协议开发的分布式 key-value 存储，可用于服务发现、共享配置以及一致性保障（如数据库选主、分布式锁等）。 Jun 21, 2024 · Note: This topic has been translated from a Chinese forum by GPT and might contain errors. 2018年12月 etcd 作为孵化项目 CNCF（云原生计算基金会），几天前 CNCF 宣布 etcd 正式毕业，成为 CNCF 顶级项目。CNCF 官方表示 etcd 项目的采用率持续增加，也有稳定的治理流程，功能已达一定成熟度。 Dec 5, 2024 · After a majority of etcd members agree to commit a request, each etcd server applies the request to its data store and persists the result to disk. Additionally, v2 auth’s semantics tend to be unwieldy in practice with respect to We would like to show you a description here but the site won’t allow us. we found this issue after the upgrade in most of the cases. 5) story #13514 - data inconsistency issue caused by snapshot restore Jul 12, 2016 · When trying to run a basic custom etcd vagrant setup, with the data-dir volumes shared with the host machine for preservation of state we run into a panic: cannot open database at /var/lib/etcd/mem Nov 21, 2022 · After recently discovered consistency problems in etcd-3. 0-3. Built on the Raft consensus algorithm, etcd provides a simple API for Fix 88095, How to detect etcd inconsistency issues in TKGI 1. Dec 21, 2023 · Existing open issues along with etcd frequently asked questions have been checked and this is not a duplicate. etcd's cluster info as below Dec 19, 2021 · Configuration for our ETCD cluster: Version: 3. This is done sequentially, one by one. # etcd 节点名称，集群中每个节点的名称必须唯一 name: etcd-node1 # etcd 数据存储目录 data-dir: /var/lib/etcd # etcd 节点之间通信的 URL，必须与 advertise-peer-urls 保持一致 listen-peer-urls: http: //192. We are not changing anything betwee our version related to etcd. 12 node, whose data is consistent with 10. 85:23 Jun 21, 2022 · I encounter a serious data inconsistent problem when using etcd 3. 256031 4004 kubelet_node_status. 16 , we went into data inconsistency issue and revisions were different. What happened? In the ETCD cluster, there is a problem of data inconsistency when performing a large number of write operations. To release storage space, follow the instructions for defragmentation in Managing etcd clusters. Could you please help to change the timestamp format as below. Learn more about Distributed Lock Systems. An etcd snapshot can be used to reset all the etcd members to the same point in time. Run etcdctl get 3 netmasterpods on 2 normal nodes. When we install our microservice standalone this issue is not reproducible. 5-data-inconsistency. For example, v3 auth has connection based authentication, rather than v2’s slower per-request authentication. Continuing from the previous example, the following creates new etcd data directories (m1. All the existing v3. Additionally, v2 auth’s semantics tend to be unwieldy in practice with respect to Mar 2, 2024 · As per etcd official documentation, etcd is defined as a strongly consistent, distributed key-value store that provides a reliable way to store data that needs to be accessed by a distributed Nov 21, 2022 · All groups and messages Mar 28, 2019 · Data inconsistency in etcd version 3. Etcd is a reliable distributed key-value store that is often used for configuration management and service discovery in large-scale systems. 32 and 4. Add etcd --enable-log-rotation boolean flag which enables log rotation if true. Ma@fda. Apr 20, 2022 · There is an automatic mechanism to detect data inconsistency. 1. The last 3 relevant logs before the first revision error occurred in the bad node. Mar 7, 2022 · I'm running a 3-member etcd cluster in a testing environment, and a k8s cluster with each kube-apiserver connecting to one etcd server via localhost. 30. 简单总结目前几个已知的etcd数据不一致案例,以及相关排查思路，后续持续更新。 mvcc: fix rev inconsistency. 1: 2380 # etcd 节点对外提供服务的客户端访问 URL listen-client-urls: http: //192. I've noticed that in the code, the sync value is updated through etcd3's API using transactions (txn), which involves comparing 'revision' to determine the outcome, codes like this: Feb 24, 2020 · start etcd // enable auth etcdctl user add root:xxx etcdctl role add root etcdctl user grant-role root root etcdctl auth enable etcdctl user add hello:world etcdctl role add hello etcdctl role grant-permission --prefix hello readwrite / (etcd role del hello/etcd user del user also can reproduce issue) stop etcd get auth_revision by using etcd Jan 14, 2019 · only differenet operation ： I stop the etcd process manually on etcd1 node，and modify the etcd cluster data when etcd1 is down， then I not clean the etcd1 node data dir and restart the etcd process， first I found data the same ， but now the data different ； This operation may cause this exception？ Apr 17, 2024 · From our analysis of data inconsistency cases, we know that inconsistencies can arise in MVCC, boltdb, and other modules due to various reasons, such as differences in the number of keys, inconsistent logical clock versions in etcd, inconsistent metrics values for put operations received by the MVCC module, and so on. Currently we get ETCD timestamps in the the following format - 2022-11-18T07:16:40. Jul 13, 2022 · A 3 etcd cluster returned inconsistent data. g. etcd, as the metadata storage of the Kubernetes cluster, is a strongly consistent KV storage widely used in the industry, but a data inconsistency bug that existed for 3 years was recently discovered-the client cannot read data on abnormal nodes after writing , That is, data loss. 2+,Leader) Feb 26, 2025 · High CPU load and resource contention were present, which led to delays in data synchronization between ETCD nodes, triggering frequent leader election attempts. It can be seen that the data in etcd on the 10. because his data is inconsistent etcd - Distributed reliable key-value store for the most critical data of a distributed system Author: Microsoft Office User Janie. Apr 5, 2023 · etcd knowledge base. It gracefully handles leader elections during network partitions and can tolerate machine failure, even in the leader node. 6 Aug 19, 2024 · Data model; etcd v3 authentication design; etcd versus other key-value stores the inconsistent state can be prolonged and it might result in counter-intuitive Mar 5, 2021 · etcd is a fast, reliable and fault-tolerant key-value database. 2. 3. 18. Note that the prefix data in the by-dev/meta/session file does not require a backup. etcd, m3. 3. However, as a rough estimate, an 8GB etcd database can typically support a Kubernetes cluster with thousands of nodes and tens of thousands of pods. This may cause the application to read inconsistent data, leading to errors or inconsistent behavior. Jan 12, 2021 · Do an upgrade, which involves copying all the data (including etcd related one) to partition2 and rebooting each node. You'll need to pick one member as the source of truth, force creating a single-member cluster, and then re-add other members (don’t forget to clear their data first). 3 生产环境分支。 Apr 18, 2014 · Etcd aims to provide linearizable registers supporting reads, writes, and CAS operations. etcd) for a three member cluster: Apr 26, 2020 · Google 输入“etcd data inconsistent” 搜索发现，并不是只有我们遇到过该问题，之前也有其他人向 etcd 社区反馈过类似问题，只是 Apr 24, 2020 · 近期我们遇到一个严重BUG，开启鉴权后，重启etcd就可能导致数据不一致，根本原因是鉴权相关操作未做幂等性，consistent index未持久化，重启会导致命令重放， 进而导致鉴权版本号不一致，放大导致mvcc数据不一致，客户端表现写进去数据读取不到。 When we installed microservice with etcd 3. we successfully reproduced it again. ETCD_VERIFY="all" environment triggers additional verification of consistency of etcd data-dir files. md Problems: Lack of adoption prevents early What happened? Specifying a revision for a range request in a transaction may cause data inconsistency. etcd is a strongly consistent, distributed key-value store that provides a reliable way to store data that needs to be accessed by a distributed system or cluster of machines. Unrecoverable failures are ones where the etcd cluster has lost more than half the nodes and they can not be brought back online. OpenShift Container Platform (OCP) versions 4. How can we reproduce it? Step 1: start a brand new Inconsistent etcd data state after a node reboot Seeing the following error: atomic-openshift-node[4004]: E0716 10:07:46. And after running for days, one of members' DB size is extremely larger than the other ones. 12 utilize the affected versions of etcd. Etcd Database Quota Low Space; Etcd GRPC Requests Slow; Etcd High Fsync Durations; Etcd High Number Of Failed GRPC Requests; Etcd Insufficient Members; Etcd Members Down; Etcd No Leader; kube-state-metrics. umd kbenh zaqa unfjzk qhwunzl ggzwj ghmn guh rduvm sxh xqih uhrpw efyd gybwgtcv ljwsi