Github user tdas commented on a diff in the pull request: https://github.com/apache/spark/pull/17246#discussion_r106722579 --- Diff: docs/structured-streaming-kafka-integration.md --- @@ -373,11 +375,204 @@ The following configurations are optional: </tr> </table> +## Producing Data to Kafka + +### Writing Streaming Queries to Kafka + +<div class="codetabs"> +<div data-lang="scala" markdown="1"> +{% highlight scala %} + +// Write key-value data from a DataFrame to a specific Kafka topic specified in an option +val s1 = df1 + .selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") + .writeStream + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .option("topic", "topic1") + .start() + +// Write key-value data from a DataFrame to Kafka using a topic specified in the data +val s2 = df2 + .selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") + .writeStream + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .start() + +{% endhighlight %} +</div> +<div data-lang="java" markdown="1"> +{% highlight java %} + +// Write key-value data from a DataFrame to a specific Kafka topic specified in an option +StreamingQuery s1 = df1 + .selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") + .writeStream() + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .option("topic", "topic1") + .start() + +// Write key-value data from a DataFrame to Kafka using a topic specified in the data +StreamingQuery s2 = df1 + .selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") + .writeStream() + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .start() + +{% endhighlight %} +</div> +<div data-lang="python" markdown="1"> +{% highlight python %} + +# Write key-value data from a DataFrame to a specific Kafka topic specified in an option +s1 = df1 \ + .selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") \ + .writeStream \ + .format("kafka") \ + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") \ + .option("topic", "topic1") \ + .start() + +# Write key-value data from a DataFrame to Kafka using a topic specified in the data +s2 = df2 \ + .selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") \ + .writeStream \ + .format("kafka") \ + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") \ + .start() + +{% endhighlight %} +</div> +</div> + +### Writing Batch Queries to Kafka + +<div class="codetabs"> +<div data-lang="scala" markdown="1"> +{% highlight scala %} + +// Write key-value data from a DataFrame to a specific Kafka topic specified in an option +df1.selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") + .write + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .option("topic", "topic1") + .save() + +// Write key-value data from a DataFrame to Kafka using a topic specified in the data +df2.selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") + .write + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .save() + +{% endhighlight %} +</div> +<div data-lang="java" markdown="1"> +{% highlight java %} + +// Write key-value data from a DataFrame to a specific Kafka topic specified in an option +df1.selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") + .write() + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .option("topic", "topic1") + .save() + +// Write key-value data from a DataFrame to Kafka using a topic specified in the data +df1.selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") + .write() + .format("kafka") + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") + .save() + +{% endhighlight %} +</div> +<div data-lang="python" markdown="1"> +{% highlight python %} + +# Write key-value data from a DataFrame to a specific Kafka topic specified in an option +df1.selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)") \ + .write \ + .format("kafka") \ + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") \ + .option("topic", "topic1") \ + .save() + +# Write key-value data from a DataFrame to Kafka using a topic specified in the data +df2.selectExpr("topic", "CAST(key AS STRING)", "CAST(value AS STRING)") \ + .write \ + .format("kafka") \ + .option("kafka.bootstrap.servers", "host1:port1,host2:port2") \ + .save() + +{% endhighlight %} +</div> +</div> + +Each row being written to Kafka has the following schema: --- End diff -- I think its better to put this section of necessary and optional columns before the examples, right after "Producing Data to Kafka". The sink options can stay here after the examples.
--- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org