Jmeter-GCP-PubSub-Sampler

Introduction

This plugin adds feature to connect to a topic to publish/subscribe messages in GCP

Required Components

1. Jmeter
2. GCP Pubsub configs

Jar Dependencies Required

• google-cloud-pubsub-1.88.0.jar or above
• gson-2.2.4.jar

Jmeter Target

• Jmeter version 5.1.1 or above
• Java 8 or above

Installation Instructions

• Download the source code from the Gitlab.
• Just do a mvn clean install (Git bash is required)
• Jar will be generated under the target directory (jmeter-pubsub-sampler-1.0.jar)
• Copy the Jar to <Jmeter Installed Directory>/lib/ext/

How to use it

Add required config element (Publisher config/ Subscriber config)

• Provide the required credentials information in the Publisher config/ Subscriber config for the project
• To publish message, Add Publisher sampler to TG and then pass the message to publish
• To receive message, Add Subscriber sampler to TG to read the mesasges

Publisher Info

Apart from config element, Publisher sampler has Gzip compression feature

• The Flag in the sampler will allow the mechanism to publish the message with/without Gzip compression
• On successfull publish of each message, GCP returns a unique Id which will be returned in response header.

Subscriber Info

The subscriber works perfectly. The current mechanism of Subscriber is

• The config elements creats a local queue to store the messages received from the GCP.
• Currently the Queue size is hardcoded to 100K
• The Subscriber sampler is bound to read it form the queue, which is already subscribed by the Message receiver(which is a separate client library's thread)
• The subscriber sampler is reading and removing the message from the queue. In future, will change the ack to be done by the sampler.
• When the susbcriber sampler is triggered and If there is no messages in the queue, It will wait until a new message arrive to process it.
• each message retrieved from the subscriber will have the message ID and publish time info along with the message.
• The message ID and publish time info will be returned in response headers and message on response body
• The subscriber sampler supports De-Compression, If the message is in gzip compressed format.

References

Below are the references which guided to build this plugin.

• https://cloud.google.com/pubsub/docs/quickstart-client-libraries
• https://cloud.google.com/pubsub/docs/publisher
• https://cloud.google.com/pubsub/docs/pull