Updating README.md

scs-100-2/README.md

@@ -7,7 +7,7 @@ A simple Example of an Event Driven Flow by the help of **SPRING CLOUD STREAM KA
 ##### properties
 
 * java.version: `11`
-* spring-cloud.version: `2020.0.3` 
+* spring-cloud.version: `2020.0.3`
 * spring-boot.version: `2.5.2`
 
 ![General Flow Diagram](material/kafka-events-intro-1002-1.svg)
@@ -28,30 +28,77 @@ run the following command line to create you jar file in `target` directory
 mvn clean package
 ```
 
-Then run the generated jar file in `target` folder, (so make sure you are in the same directory when you run the jar file
-or give the full path)
+Then run the generated jar file in `target` folder, (so make sure you are in the same directory when you run the jar
+file or give the full path)
 
 ```shell
 java -jar scs-100-0.0.1-SNAPSHOT.jar
 ```
 
-the application starts to listen on port 8080. 
+the application starts to listen on port 8080.
 
-**To scale** the application horizontally you can add the following parameter before `-jar` by adding `-Dserver.port=8081` (basically a different port) as:
+**To scale** the application horizontally you can add the following parameter before `-jar` by
+adding `-Dserver.port=8081` (basically a different port) as:
 
 ```shell
 java -Dserver.port=8081 -jar scs-100-0.0.1-SNAPSHOT.jar
 ```
-_Note: "When running multiple instances of the same application on a single machine, this path must be unique for each such instance._
-At this point you should have already seen the information about your topics", [to read more](https://kafka.apache.org/28/documentation/streams/developer-guide/config-streams.html#state-dir)
+
+_Note: "When running multiple instances of the same application on a single machine, this path must be unique for each
+such instance._
+At this point you should have already seen the information about your topics"
+, [to read more](https://kafka.apache.org/28/documentation/streams/developer-guide/config-streams.html#state-dir)
 
 ### Check Application
 
 #### Create Order or Place your Order
+
 you should now be able to place your order by calling the following `curl` command
 
 ```shell
 # assuming your app is listening on 8080
 ORDER_UUID=$(curl --silent -H 'Content-Type: application/json' -d "{\"itemName\":\"book\"}" http://localhost:8080/order | jq -r '.orderUuid') && for i in `seq 1 15`; do echo $(curl --silent "http://localhost:8080/order/status/"$ORDER_UUID); sleep 1; done;
 ```
-Note: make sure you have already installed the `jq` 
+
+Note: make sure you have already installed the `jq`
+
+## Running Multi Instances
+
+Now let’s run the same application multiple times at the same time to simulate the application redundancy. But before
+that make sure that the current application is not running.
+
+This project code comes with Nginx as LoadBalancer which has already been configured to distribute the incoming traffic
+from port 8080 and route it into 8081 and 8082.
+
+So first let’s start it in different docker-compose from root on this project “scs-100-2” as:
+
+```shell
+docker-compose -f nginx/docker-compose.yml up -d
+```
+
+Since the port 8080 is already got occupied by nginx we can run the Ordering application as follow in 2 separated
+terminal
+
+_Terminal 1:_
+
+```shell
+java -Dserver.port=8081 -jar target/scs-100-2-0.0.1-SNAPSHOT.jar
+```
+
+_And on Terminal 2:_
+
+```shell
+java -Dserver.port=8082 -jar target/scs-100-2-0.0.1-SNAPSHOT.jar
+```
+
+![General Flow Diagram](material/kafka-events-intro-1002-3.svg)
+
+_Then run our curl call command again (same as the earlier one)_
+
+```shell
+ORDER_UUID=$(curl --silent -H 'Content-Type: application/json' -d "{\"itemName\":\"book\"}" http://localhost:8080/order | jq -r '.orderUuid') && for i in `seq 1 15`; do echo $(curl --silent "http://localhost:8080/order/status/"$ORDER_UUID); sleep 1; done;
+```
+
+![General Flow Diagram](material/kafka-events-intro-1002-4.svg)
+
+