flink-examples | using Apache Flink framework to complement my blog Brewing | SQL Database library
kandi X-RAY | flink-examples Summary
kandi X-RAY | flink-examples Summary
A repository of examples of using Apache Flink framework to complement my blog Brewing Codes.
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
- Gets the next record in the buffer
- Set the follower
- Set the user number
- Opens the reader for the given split
- Gets the FileSystem
- The path
- Entry point for testing
- Writes the text to a file
- Main method for testing
- Gets input splits
- Main entry point
- Entry point for testing
- Entry point
- Sets the ratings
- Returns the graph statistics for the input path
- Closes the reader
flink-examples Key Features
flink-examples Examples and Code Snippets
Community Discussions
Trending Discussions on flink-examples
QUESTION
I am learning Apache Flink, and integrated it via Maven in IntelliJ. I tried this WordCount example from GitHub: WordCount example from GitHub
where I simply adjusted the input text.
The main part of the code producing the output is:
...ANSWER
Answered 2021-Jan-21 at 07:46WordCoiunt is the "hello world" in the streaming space.
- NUMBER shows the number of repetitions
- "florian" is twice in you input and shows up the first time with (florian,1) and the second occurs with (florian,2) if you add another "florian" to the input flink will count and show (florian,3)
QUESTION
I'm learning Flink with simple toy examples.
I have adapted the WindowWordCount
example from here and run it on this simple data file
ANSWER
Answered 2020-Sep-15 at 08:29The Trigger
for CountWindow
only triggers the window function for complete windows -- in other words, after processing windowSize
events for a given key, then the window will fire.
For example, with windowSize = 2
, only for a
and c
are there enough events. Since there is only one b
, the job ends with a partially filled window for b
.
You can use a custom trigger that also reacts to a timeout if you want to generate reports for partial count windows.
QUESTION
I am working with the clustering example provided with Flink (Kmeans) and trying to extend the functionality of it. The goal is to reduce the number of distance computations by computing a multidimensional-array consisting of the distances between each centroid, such that the distances can be found in a double[][]
array. This array must be computed at the beginning of each iteration and broadcasted, when the points are assigned clusters.
I have tried the following:
...ANSWER
Answered 2020-Mar-03 at 08:50DataSets are inherently unordered and sharded, both which are not suited for your use case.
What you want to do is to first collect all centroids in one method invocation.
QUESTION
Attempting to run the SocketWindowWordCount example tutorial found on the flink site here.
I started the flink cluster, then ran a local socket server:
...ANSWER
Answered 2019-Jul-10 at 10:14This is usually happening when you have a Flink UI tab open in your browser, which is left open from previous job deployments. So the UI is pointing to a URL with http://.../f9b3c58ca3026855fd2612e3c86551fa which is a JobID that doesn't exist. This causes the above log to show up.
QUESTION
Basically I want to deploy a Flink custom JAR file to a new AWS EMR cluster. Here is a summary of what I did. I created a new AWS EMR cluster.
Step1:Software and steps changes -
- Created a AWS EMR cluster with flink as the service. (EMR release version - 5.17.0) and clicked Flink 1.5.2 as the software configuration.
Entered the Configuration JSON:-
[ { "Classification": "flink-conf", "Properties": { "jobmanager.heap.mb": "3072", "taskmanager.heap.mb": "51200", "taskmanager.numberOfTaskSlots":"2", "taskmanager.memory.preallocate": "false",
"parallelism.default": "1" } ]
Step2:Hardware - No change in the hardware configuration.By default we have 1 master, 2 core and 0 Task instances. All are m3.xlarge type.
- Step3:General Cluster Settings - No change here.
- Step4:Security - Provided my EC2 key pair.
Once the cluster creation is ready I SSHed to the EC2 machine and tried to deploy the custom jar file. Below are the different errors I got everytime tried to deploy it via the CLI.
1)
...flink run -m yarn-cluster -yn 2 -c com.deepak.flink.examples.WordCount flink-examples-assembly-1.0.jar
ANSWER
Answered 2018-Oct-11 at 15:55You should reduce memory allocation for task manager. Currently, you are trying to allocate 51.2G of memory whereas single m3.xlarge machine has only 15G of memory and in total 30G for 2 machines cluster.
QUESTION
I'm trying to apply per window functionality on Flink's DataStream. Following is my code
...ANSWER
Answered 2018-Oct-02 at 09:18The problem is that there's a mismatch between the KeySelector used in the keyBy and the key type specified in the ProcessWindowFunction. You have specified the key using an index into the Tuple2, and as a consequence, the compiler is unable to infer that the keys will be Strings. In this situation, Flink passes the key as a Tuple.
There are a couple of ways you can fix this. If you leave the keyBy as is, then you'll need to modify the ProcessWindowFunction to use Tuple as the key type, and you'll have to cast the key to a String if you want to use it. Something like ((Tuple1)key).f0
. A better solution would be a use a more explicit key selector, such as keyBy(t -> t.f0)
, so that the keys are known to be Strings at compile time.
QUESTION
I am wondering is it possible to obtain the timestamp of record by using Flink's ingestion time mode. Considering the following flink code example (https://github.com/apache/flink/blob/master/flink-examples/flink-examples-streaming/src/main/scala/org/apache/flink/streaming/scala/examples/join/WindowJoinSampleData.scala),
...ANSWER
Answered 2018-Mar-05 at 15:15Use ProcessFunction
wich gives you a Context
, that you can use to get the element's timestamp (whether its ingestion, processing or event time).
QUESTION
I tried to treat Cassandra as the source of data in Flink with the information provided in the following links:
- Read data from Cassandra for processing in Flink
- https://www.javatips.net/api/flink-master/flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/async/AsyncIOExample.java
I got the AsyncWaitOperator
exception when I run the task. According the the first link, this exception occurs due to network problem. However, the strange thing is that I am running Cassandra on my local VM with only 10 rows of data in the target table.
@Jicaar in first link also mentions that switching from RichAsyncFunction
to RichMapFunction
can avoid the AsyncWaitOperator
exception, can someone with similar experience share how to do it in RichMapFunction
?
AsyncWaitOperator
exception trace -->
ANSWER
Answered 2018-Apr-03 at 13:53The below code should work for reading from Cassandra for batch processing in Flink.
QUESTION
I have a flink jar that sink a datastream of serializable datatype on elastic and cassandra with a beahaviour that differ from stand-alone context.
I have read about netty conflict with Flink process and I excluded it from the pom file but it follow to be included in the package
Any suggestions?
This is the exception:
...ANSWER
Answered 2018-Feb-14 at 11:28I added the argument to the conf/flink.yaml and great, it works like a charm!!!! I lost hours checking the pom file with my collegues. :) Thankkkss
REF: https://docs.datastax.com/en/developer/java-driver-dse/1.4/faq/ https://ci.apache.org/projects/flink/flink-docs-release-1.2/setup/config.html#runtime-algorithms
QUESTION
I'm trying to develop a flink stream job. The job should read from a kafka topic.
I've tried to update the example at https://github.com/dataArtisans/kafka-example/blob/master/src/main/java/com/dataartisans/ReadFromKafka.java
I want to use Flink 1.4 and Kafka 0.11.
When I try to build the (maven) project I get the following error:
...ANSWER
Answered 2017-Dec-29 at 20:29I think its because you are trying to use flink 1.3.0 according to your Pom.xml.
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install flink-examples
You can use flink-examples like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the flink-examples component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page