Post-Upgrade Steps and Troubleshooting

Prerequisite for RHEL 9.4

Note: After you have upgraded the OS to RHEL 9.4 and before you start using AppViewX, perform the steps below to update the sysctl.conf file.

To update the sysctl.conf file, execute the command below.
```
sudo vi /etc/sysctl.conf
```

Add these two lines (parameters) to the end of the file.

fs.inotify.max_user_instances=8192

fs.inotify.max_user_watches=524288

Save and exit.
Now, run the command below.
```
sudo sysctl -p
```

Starting the Services and Pods

Perform these steps after you upgrade to RHEL 8.10 or 9.4

Start the infra and application services using the following commands

To enable the services, run the command below.

systemctl enable containerd.service

systemctl enable kubelet.service

systemctl enable appviewx.service

To start the services, run the command below.

systemctl start containerd.service

systemctl start kubelet.service

systemctl start appviewx.service

Restart all the pods by executing the command below.
```
kubectl delete po –all -A –force
```
Note: Wait until all the pods are in the running state.
Verify the application status.
1. To check if all pods are up and running, run the command below.
```
kubectl get pods -A
```
2. Ensure the UI is accessible and functioning as expected.

Troubleshooting

Handling istio issues (if present).

If the istio-ingressgateway pods are stuck in 0/1 Running state, run the command below.

sudo iptables -P INPUT ACCEPT; sudo iptables -P FORWARD ACCEPT; sudo iptables -P OUTPUT ACCEPT; sudo iptables -F; sudo iptables -X; sudo iptables -Z; sudo iptables -t nat -F; sudo iptables -t nat -X; sudo iptables -t mangle -F; sudo iptables -t mangle -X; sudo iptables -t raw -F; sudo iptables -t raw -X;

This command flushes the iptables rules to resolve any networking issues related to istio.

Restart all pods (after flushing the iptables).
```
kubectl delete pods --all -A --force
```

Handling pod specific issues (if present) - If vault, mongo, or other pods start crashing with error message as xtables parameter problem: iptables-restore: unable to initialize table 'nat', do the following:
1. Manually create the iptable_filter.conf file under /etc/modules-load.d/.
2. To ensure the changes take effect after creating the above file, reboot the node.