I was trying fortio server/client application on istio. I used istoctl for injecting istio dependency and my serer pod was came up fine. But client pod was giving connection refused error due to proxy sidecar is not yet ready to handle connection request of client. Please help me addressing this issue. For reference attaching my yaml files.
This is by design and there is no way around it.
The part responsible for configuration of the iptables for capturing the traffic is run as an init container, which ensures that the required rules are in place before any of the normal pod containers start up. If you use istio for all the traffic, then until it's container is ready, no network traffic will reach in/out of the container.
You should make sure your application handles this right. Apps should be able to withstand unavailability of it's dependencies for a time, both on startup and during operation. In worst case you can introduce your own handling in form of ie. custom entrypoint that awaits for communication to be up.