Use Asynchronous Calls instead of sync when doing Network calls #76

docs/catalog/cloud/use-async-instead-of-sync.md

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+---
+version: 1.0
+submitted_by: srini1978, markus-ntt-seidl
+published_date: TBD
+category: cloud
+tags: 
+ - cloud
+ - size:medium
+---
+
+# Use Asynchronous network calls instead of synchronous
+
+## Description
+
+When making calls across process boundaries to either databases or file systems or REST APIs, use asynchronous calling patterns compared to synchronous calls. 
+
+## Solution
+
+Using asynchronous patterns frees the calling thread from being blocked on the response and hence additional work is achieved without CPU cycles being consumed. Therefore this pattern drives optimal utilization of the CPU and Memory cycles contributing to reduced energy consumption.
+
+## SCI Impact
+
+`SCI = (E * I) + M per R`  
+[Software Carbon Intensity Spec](https://grnsft.org/sci)
+
+This pattern affects the SCI as follows:
+
+- `E`: This pattern drives optimal utilization of the CPU, hence reducing energy consumption.
+- `M`: Optimized average CPU utilization can reduce the amount of resources needed which will decrease the amount of embodied carbon required to support.
+
+## Assumptions
+
+- The specific library for making asynchronous calls is available in the language being used for web development. E.g Task parallel library in C#.
+
+## Considerations
+
+- Consider higher level patterns for asynchronous communication as well, for example Queues, Topics and Streams
+
+## References
+
+- Async/Await (https://en.wikipedia.org/wiki/Async/await)
+- [Azure Well-Architected Framework Sustainability Pillar](https://learn.microsoft.com/en-us/azure/architecture/framework/sustainability/sustainability-application-design)