Handling simultaneous API requests in a shell script for production deployment
Hey everyone, I'm running into an issue that's driving me crazy. I've been banging my head against this for hours. Currently developing a solution that involves integrating multiple third-party APIs in a production environment. My objective is to execute several API calls in parallel from a shell script to improve performance, but I'm running into issues with managing the responses effectively. I started with a simple approach using `&` to background the processes: ```bash #!/bin/bash api_call_1() { curl -s http://api.example.com/endpoint1 } api_call_2() { curl -s http://api.example.com/endpoint2 } api_call_1 & api_call_2 & wait ``` While this works for firing off requests simultaneously, I'm unsure how to handle the responses properly when they arrive at different times. I've thought about redirecting outputs to individual files, but that could become messy fast, especially if I need to parse the results later. Next, I experimented with using process substitution to encapsulate the outputs: ```bash output1=$(api_call_1) output2=$(api_call_2) echo "Response from API 1: $output1" echo "Response from API 2: $output2" ``` This method simplified capturing results, yet it still blocks until each call completes, which isn’t ideal. To truly achieve parallel execution while capturing the results, I researched using `xargs` with `-P` for parallel processing: ```bash printf 'http://api.example.com/endpoint1 http://api.example.com/endpoint2 ' | xargs -n 1 -P 2 curl -s ``` This command should allow me to send requests concurrently, but it doesn’t provide an intuitive way to match responses back to their respective requests. Given the nuances of timing and response handling, what's the best way to manage parallel API requests using shell scripting? Would using a more robust tool like `GNU Parallel` be a better approach, or are there best practices I might have overlooked? Any insights from those with experience in production-level API integrations would be greatly appreciated. This is part of a larger service I'm building. Thanks in advance! My development environment is Ubuntu. I'd really appreciate any guidance on this.