Using jmeter to place messages on google-cloud pubsub - jmeter

Question

Has anyone had success in using Jmeter to load messages onto Google PubSub. I can’t find much on the web about this topic. There is a GCP pubSub plugin but it does not have a lot of instructions on how to use it.
Can JMS Publisher be used?
I don’t have much experience with any of the above.

Answer 1

The easiest way is following official documentation: Quickstart: Using Client Libraries
Install Maven
Create pom.xml file with the following content anywhere in your hard drive
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>untitled</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>libraries-bom</artifactId>
<version>20.2.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-pubsub</artifactId>
</dependency>
</dependencies>
</project>
Execute the copy-dependencies command in the folder where pom.xml lives:
mvn dependency:copy-dependencies
Copy everything from target/dependency folder to "lib" folder of your JMeter installation
Restart JMeter if it's running
Add JSR223 Sampler to your Test Plan
Put the following code into "Script" area:
import com.google.api.core.ApiFuture
import com.google.cloud.pubsub.v1.Publisher
import com.google.protobuf.ByteString
import com.google.pubsub.v1.PubsubMessage
import com.google.pubsub.v1.TopicName
import java.util.concurrent.TimeUnit
// TODO(developer): Replace these variables before running the sample.
String projectId = 'your-project-id'
String topicId = 'your-topic-id'
TopicName topicName = TopicName.of(projectId, topicId)
Publisher publisher = null
try {
// Create a publisher instance with default settings bound to the topic
publisher = Publisher.newBuilder(topicName).build()
String message = 'Hello World!'
ByteString data = ByteString.copyFromUtf8(message)
PubsubMessage pubsubMessage = PubsubMessage.newBuilder().setData(data).build()
// Once published, returns a server-assigned message id (unique within the topic)
ApiFuture<String> messageIdFuture = publisher.publish(pubsubMessage)
String messageId = messageIdFuture.get()
log.info('Published message ID: ' + messageId)
} finally {
if (publisher != null) {
// When finished with the publisher, shutdown to free up resources.
publisher.shutdown()
publisher.awaitTermination(1, TimeUnit.MINUTES)
}
}
Replace your-project-id and your-topic-id with your own values
Run your test - it should post Hello world message to the given project/topic
More information on Groovy scripting in JMeter: Apache Groovy - Why and How You Should Use It
Later on you can follow instructions from How to write a plugin for JMeter to make this functionality available "natively"