Add Validator Upgrade Guide

pages/docs/node/validator/_meta.json

@@ -1,5 +1,6 @@
 {
   "requirements": "Start Validating",
+  "upgrade-node": "Upgrade your Validator",
   "proxyaccount": "Proxy Accounts",
   "validator-rewards": "Rewards"
 }

pages/docs/node/validator/upgrade-node.mdx

@@ -0,0 +1,58 @@
+# Validator Upgrade Guide
+
+## Introduction
+
+Validators are crucial to the stability and security of the Tangle Network. This guide provides detailed steps for upgrading validators while maintaining strict uptime requirements to avoid slashing.
+
+## Preparation
+
+- Stay informed [about new releases](https://github.com/webb-tools/tangle/) from the Tangle Network community. We publish these on the [Webb twitter, and in Discord.](../../community.mdx)
+- Plan the upgrade process to minimize downtime.
+
+## Key Components
+
+### Session Keys
+
+- Stored in the client, linking your node to the staking proxy.
+- Changing keys requires waiting for the current session to finish plus two more sessions.
+
+### Keystore
+
+- Located at `/chains/Tangle/keystore`.
+- Contains private keys for signing transactions.
+- **Do not clone or copy** the keystore; generate new keys for each validator instance.
+
+## Upgrade Steps
+
+### Setting Up Validator B (Your New Validator)
+
+1. Start and sync a second node (Validator B) with the `--validator` flag.
+2. Generate session keys for Validator B.
+3. Submit a `set_key` extrinsic from your staking proxy with Validator B’s session key.
+4. Note the session when this extrinsic is executed.
+5. Keep Validator A running until two full sessions have elapsed after the current one.
+
+### Switching to Validator B
+
+1. After Session N+3, Validator B will act as your validator.
+2. Perform maintenance on Validator A.
+
+### Restoring Validator A
+
+1. Restart Validator A with the `--validator` flag and sync it.
+2. Generate new session keys for Validator A.
+3. Submit a `set_key` extrinsic with Validator A’s new session key.
+4. Keep Validator B running until two full sessions have elapsed after the current session.
+
+## Monitoring the Transition
+
+Verify the session change by looking for log messages like:
+
+```
+2019-10-28 21:44:13 Applying authority set change scheduled at block #450092
+2019-10-28 21:44:13 Applying GRANDPA set change to new set with 20 authorities
+```
+
+## Troubleshooting and Support
+
+For additional support, [join our Validator channel in Discord.](../../community.mdx)