Flink weekly(周报) 2019/25

Dear community,

本周的更新包含了一些指向开发过程中即将发生的变化的指示，最近两个关于指标的建议以及关于开发邮件列表的较小讨论。仍在处理积压的主题和讨论，每周包括一些主题和讨论。

与往常一样，请随时向此主题添加其他更新和新闻！

Flink Development

• [development-process] 早在二月，Flink社区讨论了其代码贡献过程的变化（在Jira中实现）[1]。在未来，只有提交者才能分配票据的贡献者，希望将讨论转移到贡献过程的早期阶段。新流程现已完整记录并在Flink网站上发布[2]。据我所知，下一步是相应地更改Jira权限。

• [development-process] Stephan最近开始讨论采用代码风格和质量指南来为Apache Flink做出贡献。它涵盖了Flink特定方面，如PR命名，以及一般 Java 最佳实践和在Flink等复杂系统环境中学到的经验教训。反馈是非常积极的，Robert现在要将指南分成小节并将其添加到Flink网站。[3]

  

• [releases] Flink 1.8.1最后一个当前已知的blocker已经解决，Jincheng正在创建第一个候选版本。[4]

• [releases] Flink 1.9.0的功能冻结已设置为最初提议的日期，即6月28日[5,6]。

• [metrics] 5月，Hwanju提议显着增强Flink的可用性指标，并根据失败的根本原因（主要在系统和用户代码之间）对停机时间进行分类。[8]这将使service providers更容易监控基于Flink的服务的SLA。现在讨论线程被分成两个设计文档，用于异常分类[9]和更精细的执行跟踪[10]。

• [metrics] Becket建议标准化连接器提供的指标。它定义了一组标准度量，每个source或sink应该公开（例如numBytesIn，pendingRecord）。据我所知，到目前为止，FLIP仍在投票中获得积极反馈[11]。

• Dyana提出了在官方Apache Flink版本中包含Kinesis Connector模块的可能性，因为它们现在可以在Apache 2.0许可下使用。相应的贡献正在等待中。[12]

• Xingcam开始讨论是否弃用，修复或替换DataStream API的split / select方法。它们在Flink 1.8.0中被标记为已弃用，但目前的讨论还没有得出结论，是否真的将其删除。

[1] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-A-more-restrictive-JIRA-workflow-td27344.html [2] https://flink.apache.org/contributing/contribute-code.html [3] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Adopting-a-Code-Style-and-Quality-Guide-td29524.html#a29532 [4] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Releasing-Flink-1-8-1-td29154.html [5] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Features-for-Apache-Flink-1-9-0-td28701.html [6] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/ANNOUNCE-Feature-freeze-for-Apache-Flink-1-9-0-release-td29751.html [7] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Proposal-for-Flink-job-execution-availability-metrics-impovement-td28882.html [8] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-33-Standardize-connector-metrics-td26869.html [9] https://docs.google.com/document/d/1pcHg9F3GoDDeVD5GIIo2wO67Hmjgy0-hRDeuFnrMgT4/edit#heading=h.v3ssap5tvszp [10] https://docs.google.com/document/d/1oLF3w1wYyr8vqoFoQZhw1QxTofmAtlD8IF694oPLjNI/edit#heading=h.9zul23uwx8c6 [11] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-FLIP-33-Standardize-connector-metrics-td29527.html [12] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/Updating-Kinesis-Connector-to-latest-Apache-licensed-libs-td29559.html#a29566 [13] http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/About-Deprecating-split-select-for-DataStream-API-td29617.html

Notable Bugs

• [FLINK-12871] [1.7.2] [ 1.8.0] The documentation how to setup SSL for Flink's REST API and intra-cluster communication was erroneous. Fixed in [1.7.3] [1.8.1]. [14]

• [FLINK-12912] [1.6.4] [1.7.2] [ 1.8.0] With the configuration parameter "task.checkpoint.alignment.max-size" users can limit the data buffered during the alignment phase of a checkpoint. Once reached, the checkpoint is aborted. Currently, this check does not work correctly when one checkpoint subsumes another one. Unresolved. [15]

[14] https://issues.apache.org/jira/browse/FLINK-12871 [15] https://issues.apache.org/jira/browse/FLINK-12912

Events, Blog Posts, Misc

• 本周在柏林Buzzwords和欧洲梁峰会上进行了几次与Flink相关的会谈。来自柏林Buzzwords的会谈已在线提供[16]。不确定是否有Beam Summit的录音，但肯定看到很多幻灯片在Twitter上分享。

• Liu Biao 在Flink进行了约400名参与者的在线培训 [16].

• 接下来几周会有几场Meetup:

• 2019/06/24: Cloud Native Meetup in Aarhus with a Flink talk by Lasse Nedergard (TrackUnit) [18]

• 2019/06/26: Bay Area Apache Flink Meetup with talks by Zendesk, Parag Kesar and Ben Liu (Pinterest) and Ken Krugler (Scale Unlimited) [19]

• 2019/07/01: Paris Apache Beam Meetup with a Flink talk by myself (Ververica) [20]

• 2019/07/05: Apache Flink Meetup Munich with talks by Steffen Hausmann (AWS) and Michel David (Ryte) [21]

[16] https://berlinbuzzwords.de/19/sessions [17] https://zh.ververica.com/developers/flink-training-course2 [18] https://flink.apache.org/2019/06/05/flink-network-stack.html [19] https://www.meetup.com/Cloud-Native-Aarhus/events/261346897/ [20] https://www.meetup.com/Bay-Area-Apache-Flink-Meetup/events/262216929 [21] https://www.meetup.com/Paris-Apache-Beam-Meetup/events/261775884/ [22] https://www.meetup.com/Apache-Flink-Meetup-Munich/events/261282757/