Capacity planning

help/performance/TOC.md

@@ -12,6 +12,7 @@ user-guide-description: Optimize the performance of your Adobe Commerce or Magen
 - [Development environment recommendations](development-environment.md)
 - [Configuration best practices](configuration.md)
 - [Deployment flow](deployment-flow.md)
+- [Capacity Planning](capacity-planning.md)
 - [High-throughput order processing](high-throughput-order-processing.md)
 - Advanced concepts {#performance-best-practices}
   - [Advanced setup](advanced-setup.md)

help/performance/capacity-planning.md

@@ -0,0 +1,73 @@
+---
+title: Capacity Planning
+description: Learn about the steps necessary for capacity planning for  Adobe Commerce or Magento Open Source. 
+---
+
+## Capacity Planning
+## Benefits
+
+- Keeping the cost low/avoid over-spend on resource
+- Reliability
+- Intelligent resource allocation
+- Help in High Availability & scalability
+- Avoid emergencies
+
+## Terminology
+
+
+### Latency
+
+![capcity-planning-letency](../assets/performance/images/capacity-planning-letency.png)
+
+Additional time spend/delay between user's action and web application's response to that action.[Caching](https://devdocs.magento.com/guides/v2.4/frontend-dev-guide/cache_for_frontdevs.html?itm_source=devdocs&itm_medium=quick_search&itm_campaign=federated_search&itm_term=cach) is used to improve latency times.
+
+
+ ###Throughput
+
+``Throughput = number of completed requests / time to complete the requests``
+
+![capcity-planning-throughput](../assets/performance/images/capacity-planning-thoughput.png)
+
+Number of action per unit or number of processed over a given interval of time. For example if user perform 60 transactions in minute TPS would be 60/60 TPS = 1TPS.
+considered an average of 1 TPS considering users uniformly accessing the system over 60 seconds.this of course means that we can also expect all users coming within a single second which means a 60 TPS max peak load
+
+**Application server**
+
+Not to confuse with a load balancer (Nginx), an application server is something that runs your Ruby,Node or PHP application listens to the TCP socket, accepts HTTP request, and returns the response from the application.
+
+**Under-provisioned:** 
+
+lack of capacity which leads to higher response time or more frequent 502 Bad Gateway responses.
+
+**Over-provisioned:** 
+
+running more capacity than you actually need and probably wasting money
+
+**Availablity**
+
+The availability of a system is determined by the following equation, which yields a percentage result.
+
+``x = (n - y) * 100/n``
+
+where 'n' is the total number of minutes in a given calendar month and 'y' is the total number of minutes that service is unavailable in a given calendar month.
+
+| Availability(%)       | Downtime per year  | Downtime per month    |
+| :---        |    :----:   |          ---: |
+| 90%   | 36.5 days       | 72 hours   |
+| 95%   | 18.25 days      | 36 hours       |
+| 97%   | 10.96 days        | 21.6 hours    |
+| 99%   | 3.65 days      | 7.20 hours       |
+| 99.9%   | 8.76 hours        | 43.8 minutes    |
+| 99.99%   | 52.56 minutes      | 4.32 minutes       |
+
+[Clustering](https://devdocs.magento.com/cloud/architecture/pro-architecture.html?#pro-cluster-scaling) and Load balancing technique to achieve high availability by providing redundancy at software and hardware level
+
+## Scalability
+
+Scalability is the ability to handle requests in proportion to available hardware resources.system should ideally handle increase/decrease in requests without affecting the overall throughput
+
+- Vertical scalability or Scale Up (increase performance of a server by increasing its memory, processing power)
+- Horizontal scalability or Scale Out (deploy more instances of the same type of server)
+
+## calculation
+![Capcity-planning-calculation](../assets/performance/images/capacity-planning.png)

help/performance/overview.md

@@ -7,6 +7,13 @@ description: Follow these best practices to optimize the performance of your Ado
 
 The _Performance Best Practices_ guide provides recommendations and instructions for optimizing the performance of your production deployment. Technical users who are responsible for maintaining stores in production mode should use the best practices described in this guide to help ensure their stores run at peak efficiency at all times.
 
+>Performance refers to the speed with which a system responds to the user requests.
+
+Performance depends upon  
+- [User load that your system support](https://devdocs.magento.com/guides/v2.4/config-guide/cli/config-cli-subcommands-perf-data.html). 
+- [Adequate Hardware Resources](https://devdocs.magento.com/guides/v2.4/performance-best-practices/hardware.html). 
+- [How your system scales](https://devdocs.magento.com/cloud/architecture/scaled-architecture.html).
+
 ## Assumptions
 
 *  You installed Adobe Commerce or Magento Open Source using [Composer](../installation/composer.md).