[ANNOUNCE] Weekly Community Update 2019/31

[Konstantin Knauf <ko...@ververica.com>]

Dear community,

happy to share this week's community update with news about a Flink on
PyPi, code style proposals, Flink 1.9.0 RC1, Flame Graphs in the WebUI and
a bit more.

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

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

* [development process] Andrey has opened three threads following up on the
recently published "code style and quality guide". They deal with the usage
of Java Optional [1] (tl;dr: only as return type in public APIs) ,
Collections with initial capacity [2] (tl;dr: only if trivial) and how to
wrap long arguments lists and chained method calls [3] (tl;dr: yes, but
details still open).

* [python] Jingcheng has started a voting thread on publishing PyFlink to
PyPi. Name will be "apache-flink" and the account will be managed by the
Apache Flink PMC. The vote has passed unanimously. [4]

* [metrics] David proposed to add a CPU flame graph [5] for each Task to
the WebUI (similar to the backpressure monitor). A CPU flame graph is a
visualisation method for stack trace samples, which makes it easier to
determine hot code paths. This has been well received and David is looking
for a comitter to sheperd the effort. [6]

* [releases] Kurt announced a second preview RC (RC1) for Flink 1.9.0 to
facilitate ongoing release testing. There will be no vote on this RC. [7]

* [filesystems] Aljoscha proposed to removev flink-mapr-fs module from
Apache Flink due to recent problems pulling its dependencies. If removed
the MapR filesytem could still be used with Flink's HadoopFilesystem [8]

* [client] Tison has published a first design document on the recently
discussed improvements to Flink's client API. [9]

[1]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-CODE-STYLE-Usage-of-Java-Optional-tp31240.html
[2]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-CODE-STYLE-Create-collections-always-with-initial-capacity-tp31229.html
[3]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-CODE-STYLE-Breaking-long-function-argument-lists-and-chained-method-calls-tp31242.html
[4]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/VOTE-Publish-the-PyFlink-into-PyPI-tp31201.html
[5] http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html
[6]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-CPU-flame-graph-for-a-job-vertex-in-web-UI-tp31188.html
[7]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/PREVIEW-Apache-Flink-1-9-0-release-candidate-1-tp31233.html
[8]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Removing-the-flink-mapr-fs-module-tp31080.html
[9]
http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Flink-client-api-enhancement-for-downstream-project-tp25844.html

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

Nothing for 1.6/1.7/1.8 that came to my attention.

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

* *Nico Kruber *published the second part of his series on Flink's network
stack. This time about metrics, monitoring and backpressure. (This slipped
through last week.) [10]

[10] https://flink.apache.org/2019/07/23/flink-network-stack-2.html

Cheers,

Konstantin (@snntrable)

-- 

Konstantin Knauf | Solutions Architect

+49 160 91394525


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