Imagine you’re a DevOps engineer tasked with automating the creation of hundreds of VLAN pools across multiple data centers. You’ve narrowed down your options to two popular tools: Postman and Ansible. While both can interact with APIs, their performance characteristics can vary significantly, especially for bulk operations.

Let’s dive into the key differences between Postman and Ansible and explore how to optimize for speed.

Postman: Built for Agility

Postman is a versatile tool primarily designed for manual API testing and interaction.

Its user-friendly interface and streamlined request-response handling make it ideal for:

  • Testing and debugging APIs
  • Simulating user interactions
  • Exploring API functionality quickly

Ansible: Designed for Automation

On the other hand, Ansible is a powerful infrastructure automation and configuration management tool. While it can interact with APIs, it has additional layers of functionality, such as task execution, dependency management, error handling, and role-based organization of automation code.

These features are essential for:

  • Automating infrastructure provisioning
  • Deploying configurations consistently
  • Managing complex IT environments at scale

Postman vs. Ansible: The Performance Trade-off

While both tools interact with APIs, their core functionalities lead to performance differences:

  • Overhead: Ansible includes additional layers for task execution, dependency management, and error handling. These features add essential automation capabilities but can introduce some overhead compared to Postman’s streamlined request-response handling.
  • Bulk Operations: Postman excels at sending individual requests quickly. However, Ansible’s looping capabilities can be advantageous for bulk operations, such as creating hundreds of VLAN pools. By defining the configurations once and iterating through them, Ansible reduces redundancy and API calls, potentially improving efficiency.

Performance Baseline: A Balancing Act

Let’s consider a real-world scenario where you need to create 200 VLAN pools in an ACI APIC environment:

  • With Postman: Creating 200 VLAN pools can be achieved in approximately 2 minutes, thanks to Postman’s efficient handling of individual requests.
  • With Ansible: Using a straightforward Ansible script, the same task could take over an hour due to the additional overhead and potential inefficiencies in handling bulk operations.

However, it’s crucial to note that these timings can vary based on factors such as API complexity, network conditions, and Ansible configurations.

Optimizing Ansible for Speed

While Postman may outperform Ansible for simple API interactions, there are ways to optimize Ansible’s performance for complex automation tasks or large-scale infrastructure management.

Here are some tips:

  1. Utilize Loops: Reduce redundancy by defining configurations once and looping through them.
    For example:
  2. Explore Asynchronous Modules: Modules like async or community.async enable parallel task execution, potentially speeding things up.
  3. Consider Fact Caching: Disable fact caching (if not necessary) to improve performance for subsequent runs.
  4. Optimize SSH Connections: For large deployments, use SSH ControlMaster and ControlPersist options in ansible.cfg.
  5. Profile Your Playbooks: Tools like profile_tasks or profile_roles can help identify performance bottlenecks within your playbooks.

Beyond Speed: Choosing the Right Tool

Performance is just one aspect to consider when selecting a tool.

Here’s when each tool shines:

  • Choose Postman for:
    • Interactive API exploration and testing
    • Debugging and troubleshooting APIs
    • Sending quick, individual API requests
  • Choose Ansible for:
    • Automating repetitive API interactions at scale
    • Managing infrastructure configurations consistently across environments
    • Implementing complex workflows with conditionals and error handling

Ultimately, the choice between Postman and Ansible depends on your specific use case and requirements.

Wrapping Up

While Postman is designed for efficient manual API testing and interaction, Ansible’s strength lies in its infrastructure automation capabilities. For simple API interactions, Postman may outperform Ansible in terms of execution time. However, when dealing with complex automation tasks or large-scale infrastructure management, Ansible’s performance can be optimized using techniques like loops, parallel execution, and optimized modules.

Have you experienced performance differences between Postman and Ansible? Share your thoughts and experiences in the comments below! And don’t forget to try out the optimization techniques we discussed to supercharge your Ansible playbooks.

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Stuart Clark

Senior Developer Advocate Of Community, AWS