Publishing Binary Events via Kafka¶
Purpose:¶
This application demonstrates how to configure WSO2 Streaming Integrator Tooling to send sweet production events via Kafka transport in Binary format.
Prerequisites:¶
- Setup Kafka.
- Kafka libs to be added and converted to OSGI from {KafkaHome}/libs are as follows.
- kafka_2.11-0.10.0.0.jar
- kafka-clients-0.10.0.0.jar
- metrics-core-2.2.0.jar
- scala-library-2.11.8.jar
- zkclient-0.8.jar
- zookeeper-3.4.6.jar
- Add the OSGI converted kafka libs to
{WSO2SIHome}/lib
. - Add the kafka libs to
{WSO2SIHome}/samples/sample-clients/lib
.
- Kafka libs to be added and converted to OSGI from {KafkaHome}/libs are as follows.
- Save this sample.
- If there is no syntax error, the following messages would be shown on the console.
Siddhi App PublishKafkaInBinaryFormat successfully deployed.
Note:¶
To convert Kafka libs to OSGI,
1. Create a folder (Eg: Kafka) and copy Kafka libs to be added from {KafkaHome}/libs
.
2. Create another folder(Eg: Kafka-osgi, This folder will have the libs that converted to OSGI).
3. Navigate to {WSO2SIHome}/bin
and issue the following command.
* For Linux:
./jartobundle.sh <path/kafka> <path/kafka-osgi>
* For Windows:
./jartobundle.bat <path/kafka> <path/kafka-osgi>
4. If converted successfully then for each lib, following messages would be shown on the terminal.
- INFO: Created the OSGi bundle <kafka-lib-name>.jar for JAR file <absolute_path>/kafka/<kafka-lib-name>.jar
5. You can find the OSGi converted libs in kafka-osgi folder. You can copy that to {WSO2SIHome}/lib
.
Executing the Sample:¶
- Navigate to
{KafkaHome}
and start zookeeper node using following command.bin/zookeeper-server-start.sh config/zookeeper.properties
- Navigate to
{KafkaHome}
and start kafka server node using following command.bin/kafka-server-start.sh config/server.properties
- Navigate to
{WSO2SIHome}/samples/sample-clients/kafka-consumer
and runant
command with following arguments.ant -DisBinaryMessage=true -DtopicList=kafka_result_topic -Dtype=binary
- Start the Siddhi application by clicking on 'Run'.
- If the Siddhi application starts successfully, the following messages would be shown on the console.
- PublishKafkaInBinaryFormat.siddhi - Started Successfully! - Kafka version : 0.10.0.0 - Kafka commitId : 23c69d62a0cabf06 - Kafka producer created.
Testing the Sample:¶
Send events with kafka server, through event simulator:¶
- To open event simulator by clicking on the second icon or press Ctrl+Shift+I.
- In the Single Simulation tab of the panel, select values as follows:
- Siddhi App Name: PublishKafkaInBinaryFormat
- Stream Name: SweetProductionStream
- In the batchNumber field and lowTotal fields, enter '1', '85.5' respectively and then click Send to send the event.
- Send some more events.
Publish events with curl command:¶
Open a new terminal and issue the following command.
curl -X POST -d '{"streamName": "SweetProductionStream", "siddhiAppName": "PublishKafkaInBinaryFormat", "data": [1, 85.5]}' http://localhost:9390/simulation/single -H 'content-type: text/plain'
Publish events with Postman:¶
- Install 'Postman' application from Chrome web store.
- Launch the application.
- Make a 'Post' request to 'http://localhost:9390/simulation/single' endpoint. Set the Content-Type to 'text/plain' and set the request body in json format as follows,
{"streamName": "SweetProductionStream", "siddhiAppName": "PublishKafkaInBinaryFormat","data": [1, 85.5]}
- Click 'send'. If there is no error, the following messages would be shown on the console.
"status": "OK", "message": "Single Event simulation started successfully"
Viewing the Results:¶
It will print the results in binary format.
Notes:¶
If the message "'Kafka' sink at 'LowProducitonAlertStream' has successfully connected to 'http://localhost:9092'
does not appear, it could be due to port 9092, defined in the Siddhi application is already being used by a different program. To resolve this issue, please do the following,
* Stop this Siddhi application (Click 'Run' on menu bar -> 'Stop')
* Change the port 9092 to an unused port, in this Siddhi application's source configuration.
* Start the application and check whether the specified messages appear on the console.
@App:name("PublishKafkaInBinaryFormat")
@App:description('Send events via Kafka transport using Binary format')
define stream SweetProductionStream (batchNumber long, lowTotal double);
@sink(type='kafka',
topic='kafka_result_topic',
bootstrap.servers='localhost:9092',
is.binary.message='true',
@map(type='binary'))
define stream LowProductionAlertStream (batchNumber long, lowTotal double);
@info(name='EventsPassthroughQuery')
from SweetProductionStream
select *
insert into LowProductionAlertStream;
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