[ANNOUNCE] Weekly Community Update 2019/32

[Konstantin Knauf-3]

Dear community,

happy to share this week's community update. The first real release
candidate of Apache Flink 1.9.0 has been published and the developer
community has moved more towards the 1.10 development cycle with more
discussion threads popping up again.

As always, please feel free to add additional updates and news to this
thread!

*Personal Note:* There will be no weekly community update in the next three
weeks as I will be on vacation :). The next update will be on the 8th of
September, which will then cover four weeks instead of one.

Flink Development
===============

* [releases] The voting thread on *RC2 for Apache Flink 1.9.0* has just
started. It will be open for at least 72 hours. [1,2]

* [development] Chesnay has started a discussion on *splitting up Flink's
main repository* to tackle build time issues and an ever increasing number
of pull requests. So far, the majority of answers is in favor of keeping
the mono repo and tackling the problems differently via a more
sophisticated build system, project structure, etc. It seems these
alternatives deserve a more detailed investigation. [3]

* [development process] Stephan has raised the point of *post-feature-freeze
contributions* to Flink 1.9.0 in a discussion thread on the mailing list
last week. The thread also contains a few proposals e.g. to formalize the
process in the future, which probably need to be discussed in separate
threads in the future. [4]

* [resource management] Xintong has startd a discussion on FLIP-49 to
improve and unify the *memory configuration of TaskManagers*. Its goals are
to unify the memory configuration for batch and stream processing, to
simplify automatically configure RocksDB and to simplify the configuration
of the different memory pools. [5]

* [documentation] Marta has written a *style guide for our documentation*
based on best practices and other successful Open Source projects. More
feedback welcome! [6]

* [documentation] Myself and Fabian have recently contributed a *docker-based
playground* to the Getting Started section of the documentation. This lead
to a follow up discussion of how to publish the required Docker Images. [7]

* [development process] The *style and quality guide* has finally been
published on the project website. [8]

* [sources] Zhijang has started a discussion to start with the integration
of the *SourceReader* with the mailbox of the StreamTask, which is proposed
as part of FLIP-27 (Refactor Source Interface). [9]

[1]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-Apache-Flink-Release-1-9-0-release-candidate-2-tp31542.html
[2]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/ANNOUNCE-Progress-updates-for-Apache-Flink-1-9-0-release-tp30565.html
[3]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Repository-split-tp31417.html
[4]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Merging-new-features-post-feature-freeze-tp31469.html
[5]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-49-Unified-Memory-Configuration-for-TaskExecutors-tp31436.html
[6]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/Discuss-FLIP-42-Documentation-Style-Guide-tp31370.html
[7]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Flink-Docker-Playgrounds-tp31496.html
[8]
https://flink.apache.org/contributing/code-style-and-quality-preamble.html
[9]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Integrate-new-SourceReader-with-Mailbox-Model-in-StreamTask-tp31549.html

Notable Bugs
===========

* [FLINK-13586] [1.8.1] The signature of
org.apache.flink.api.java.ClosureCleaner#clean was changed between 1.8.0
and 1.8.1. Hence, no application calling this method compiled against Flink
1.8.0 can be run on a Flink 1.8.1 cluster. For example, this includes any
application using the Kafka or Cassandra Connector. [10]

* [FLINK-13537] [1.8.1] [1.7.2] [1.6.4] If an exactly-once Kafka Producer
is rescaled and the "pool size" (# of transactionanl ids per subtask) is
changed at the same time, the transactional ids of different subtasks might
overlap, which should never happen. Fortunately, users can easily avoid
such a scenario until this is fixed. [11]

[10] https://issues.apache.org/jira/browse/FLINK-13537
[11] https://issues.apache.org/jira/browse/FLINK-13586

Events, Blog Posts, Misc
====================

* *Hequn* is now an Apache Flink Committer. Congratulations! [12]
* Upcoming Meetups
    * *Roshan Naik* of Uber and *Sijie Guo* of StreamNative speak the next
Seattle Flink Meetup on the 22nd of August about Kappa+ and Flink with
Pulsar respectively. [13]
    * *Luca Giovagnoli *of Yelp will speak at the ACM San Francisco meetup
about a machine learning application on Apache Flink. [14]
    * There is a full-day of Apache Pulsar talks at the Apache Pulsar
Meetup Beijing on the 17th of August. This also includes a talk on state
management in Apache Flink by *Yun Tang*. [15]

[12]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/ANNOUNCE-Hequn-becomes-a-Flink-committer-tp31378.html
[13] https://www.meetup.com/seattle-flink/events/263782233
[14]
https://www.eventbrite.com/e/apache-pulsar-meetup-beijing-tickets-67849484635
[15] https://www.meetup.com/acm-sf/events/263768407/

Cheers,

Konstantin (@snntrable)

--

Konstantin Knauf | Solutions Architect

[phone]


Planned Absences: 10.08.2019 - 31.08.2019, 05.09. - 06.09.2019


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