Update 06-ETCD-in-HA.md

docs/10-Install/06-ETCD-in-HA.md

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 # ETCD in HA
 
-  Take me to [Lecture](https://kodekloud.com/courses/539883/lectures/9808331)
+  Take me to [Lecture](https://kodekloud.com/courses/539883/lectures/9808331)
+
+In this section, we will discuss about ETCD in HA mode 
+
+#### Objectives
+- What is ETCD?
+- What is a key-value store?
+- How to get started quickly?
+- How to operate ETCD?
+- What is distributed system?
+- How ETCD operates?
+- RAFT Protocol
+- Best Practices on number of nodes
+
+#### Quorum
+- Quorum is the minimum number of nodes that must be available for the cluster to function properly or make a successful right in case of 3, we know its 2. 
+- For any given number of nodes, the quorum is the total number of nodes divided by 2 + 1.
+
+  ![qm1](../../images/qm1.PNG)
+
+  ![qm2](../../images/qm2.PNG)
+
+#### Getting Started
+- Download the binary
+  ```
+  $ wget -q --http-only https://github.com/coreos/etcd/releases/download/v3.3.9/etcd-v3.3.9-linux-amd64.tar.gz
+  ```
+- Extract it
+  ```
+  $ tar -xvzf etcd-v3.3.9-linux-amd64.tar.gz
+  ```
+- Move the etcd binaries to /usr/local/bin/
+  ```
+  $ mv etcd-v3.3.9-linux-amd64/etcd* /usr/local/bin/
+  ```
+- Create directories
+  ```
+  $ mkdir -p /etc/etcd /var/lib/etcd
+  ```
+- Copy TLS certs
+  ```
+  $ cp ca.pem kubernetes-key.pem kubernetes.pem /etc/etcd/
+  ```
+
+#### Configure the etcd service
+
+  ![etcds1](../../images/etcds1.PNG)
+
+#### ETCDCTL
+- The etcdctl utility has 2 versions
+  - V2 
+  - V3
+
+- Set etcdctl_api environment variable to 3
+  ```
+  $ export ETCDCTL_API=3
+  ```
+
+#### Number of Nodes
+
+  ![nn1](../../images/nn1.PNG)
+
+#### Our Lab Design
+
+  ![nn2](../../images/nn2.PNG)
+
+#### K8s Reference Docs
+- https://github.com/etcd-io/etcd/releases
+
+