examples-scala | Stream Processing with Apache Flink - Scala Examples

by streaming-with-flink Scala Version: Current License: Apache-2.0

X-Ray Key Features Code Snippets Community Discussions(4)Vulnerabilities Install Support

kandi X-RAY | examples-scala Summary

examples-scala is a Scala library typically used in Big Data, Spark applications. examples-scala has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

Stream Processing with Apache Flink - Scala Examples

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Support

examples-scala has a low active ecosystem.

It has 349 star(s) with 191 fork(s). There are 17 watchers for this library.

It had no major release in the last 6 months.

There are 5 open issues and 4 have been closed. On average issues are closed in 7 days. There are 1 open pull requests and 0 closed requests.

It has a neutral sentiment in the developer community.

The latest version of examples-scala is current.

Quality

examples-scala has 0 bugs and 11 code smells.

Security

examples-scala has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

examples-scala code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

examples-scala is licensed under the Apache-2.0 License. This license is Permissive.

Permissive licenses have the least restrictions, and you can use them in most projects.

Reuse

examples-scala releases are not available. You will need to build from source code and install.

It has 1887 lines of code, 122 functions and 34 files.

It has low code complexity. Code complexity directly impacts maintainability of the code.

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examples-scala Key Features

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examples-scala Examples and Code Snippets

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Community Discussions

Trending Discussions on examples-scala

Do I need a JAR file to run a Flink application?

how to run first example of Apache Flink

"Stream Processing with Apache Flink" how to run book code from IntelliJ?

Null pointer exception with GenericWriteAheadSink and FileCheckpointCommitter in Flink 1.8

QUESTION

Do I need a JAR file to run a Flink application?

Asked 2022-Jan-20 at 21:29

I am working through the book Stream Processing with Apache Flink by Fabian Hueske and Vasiliki Kalavri.

The book includes an example Flink application and I want to figure out how to run the file. It is a scala file located here in their github repo.

Must I turn it into a JAR file before I run it? If so, how do I convert the file to JAR?

...

ANSWER

Answered 2022-Jan-20 at 21:29

Except for SQL queries submitted with Flink‘s SQL client, a user needs to package a JAR file. Usually, a Flink program file can be packaged using a Maven or Gradle project:

https://nightlies.apache.org/flink/flink-docs-release-1.14/docs/dev/datastream/project-configuration/#maven-quickstart

Source https://stackoverflow.com/questions/70793217

QUESTION

how to run first example of Apache Flink

Asked 2020-Apr-23 at 16:38

I am trying to run the first example from the oreilly book "Stream Processing with Apache Flink" and from the flink project. Each gives different errors

Example from the book gies NoClassDefFound error Example from flink project gives java.net.ConnectException: Connection refused (Connection refused) but does create a flink job, see screenshot.

Detail below

Book example

java.lang.BootstrapMethodError: java.lang.NoClassDefFoundError:scala/runtime/java8/JFunction1$mcVI$sp at io.github.streamingwithflink.chapter1.AverageSensorReadings$$anon$3.createSerializer(AverageSensorReadings.scala:50)

The instructions from the book are:

download flink-1.7.1-bin-scala_2.12.tgz
extract
start cluster ./bin/start-cluster.sh
open flink's web UI http://localhost:8081

this all works fine

Download the jar file that includes examples in this book
run example

...

ANSWER

Answered 2020-Apr-06 at 21:59

I tried to reproduce the failing AverageSensorReadings example, but it was working on my setup. I'll try look deeper into it tomorrow.

Regarding the SocketWindowWordCount example, the error message indicates that the Flink job failed to open a connection to the socket on port 9000. You need to open the socket before you start the job. You can do this for example with netcat:

Source https://stackoverflow.com/questions/61043860

QUESTION

"Stream Processing with Apache Flink" how to run book code from IntelliJ?

Asked 2020-Apr-15 at 16:40

As described in this post I have been unable to successfully run any code from the book "Stream Processing with Apache Flink, including the precompiled jar.

It is not my practice to use an IDE but I thought I would try to use IntelliJ as Chapter 3 "Run and Debug Flink Applications in an IDE" describes how to do that specifically for the code for this book.

The book describes a project import process that I have not found a way to use. It describes setting options on import, for example select Maven. I have not found a way to set any options on import.

I am able to import a project and run code. The code fails, looks like with missing dependency. Maybe because it isn't a Maven project?

Here are steps to reproduce

git clone https://github.com/streaming-with-flink/examples-scala.git

Start IntelliJ

Choose "Open or Import" and Select the "examples-scala/" folder. The project imports with no chance to select options.

Now I have a project

Browse to AverageSensorReadings class, open, and run.

Errors with

java.lang.NoClassDefFoundError: org/apache/flink/api/common/typeinfo/TypeInformation

How can I run this code in IntelliJ?

...

ANSWER

Answered 2020-Apr-15 at 16:40

I see that flink dependencies have provided scope in Maven - this means that thay are not included into the classpath when you running the application. Most likely the application is meant to be run on environment where these dependencies already exist (e.g. Hadoop). To be able to run it from from IDE set Include dependencies with "Provided" scope option in Run Configuration:

Source https://stackoverflow.com/questions/61232605

QUESTION

Null pointer exception with GenericWriteAheadSink and FileCheckpointCommitter in Flink 1.8

Asked 2020-Feb-12 at 15:53

I'm implementing a custom NSQ sink for Flink. I have it working as a subclass of RichSinkFunction, but I'd like to get the write-ahead log implementation working for extra data integrity.

Using O'Reilly's WriteAheadSinkExample available here, I attempted to implement my own:

...

ANSWER

Answered 2020-Feb-11 at 13:34

The issue here is most certainly the fact that You never call the open() method of the superclass. This will cause some of the variables to be uninitialized. This should be solved by calling the super.open() inside Your open() method.

Source https://stackoverflow.com/questions/60160242

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

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Install examples-scala

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