Jmeter | Generate UUID (Unique Identifier)

What is UUID?

A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. UUID is almost unique as its length and random.

Problem Statement:

As an Automation Tester,
I want to generate/create UUID 
So that I can pass SAME UUID to all subsequent requests under Test Plan

Solution:

ALTHOUGH THERE IS NO DEDICATED SAMPLER IN JMETER TO GENERATE UUID / GUIDS BUT YOU CAN USE THE BUILT-IN FUNCTIONS TO GENERATE THEM.

The JMeter function __UUID function ensures that the Type 4 UUID (also known as GUID) structure will always be returned.

It consists of one group of 8 hexadecimal digits, followed by three groups of 4 hexadecimal digits each, followed by one group of 12 hexadecimal digits. The following example UUID shows the groupings of hexadecimal digits in an UUID:

c69e0dd1-ac6b-4f2b-8d59–5d4e8743eecd

Type 1 UUID is time-based, Type 2 UUID is name-based and Type 4 UUID is randomly generated. So anywhere a random GUID structure is required, feel free to use the __UUID function. It will guarantee the structure will have a unique nature, as in the example below:

([A-Z0–9]{8}-[A-Z0–9]{4}-[A-Z0–9]{4}-[A-Z0–9]{4}-[A-Z0–9]{12})

Implementation:

Jmeter function __UUID() can be used with different Jmeter component like pre-processor, beanshell , etc based on the need. Let’s explore few of them.

A) Through “User Parameters” (Pre Processor)

• Add User Parameters Pre Processor (Right click on Thread Group > Add > Pre Processor > User Parameter)

Add User Parameters Pre Processor

• Define your variable which will act as unique GUID / UUID (Ex: requestIndex) and specify value as ${__UUID()} (In-build function of Jmeter)

Define user parameter

• Now, we have requestIndex variable available as UUID throughout the test plan which we can use in any subsequent requests. ${requestIndex}

As an example,

Pass user parameter UUID to the HTTP requests

B) Through “Bean shell Pre Processor”

• Add Bean shell Pre Processor (Right click on Thread Group > Add > Pre Processor > Bean shell Pre Processor)

• Write Groovy script to generate UUID.

vars.put("requestIndex", UUID.randomUUID().toString())
print(requestIndex)

Add groovy script to generate UUID

• Now, we have requestIndex variable available as UUID throughout the test plan which we can use in any subsequent requests. ${requestIndex}
• As an example,

Pass user parameter UUID to the HTTP requests

Note: we can also use Bean shell sampler as well and have similar code inside.

For Better Debugging Purpose —

Just add below component in order to debug result better -

• Debug sampler (Right click on Thread Group > Add > Sampler > Debug sampler)
• View results Tree (Right click on Thread Group > Add > Listener > View results Tree)

Validate UUID

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