Is there any plan to add the startup probe in addition to the liveness and readiness probes? At the moment, we are still facing 503 Temporary not available during high load until the app starts, and it’s difficult to understand how long the application is taking to start up.
We don’t plan to add startup probe at the moment, because it is meant primarily for legacy application which are too tedious to modify the code of.
If you have a readiness probe in place, and have configured at least 2 instances minimum of your application to be running at all time, it should be enough.
If you still see 503 after that, it means your readiness probe check is not accurate, meaning that it returns that the application is ready, while in fact it is still not.
To quickly check if it is due to that, increase the
Initial Delay (in seconds) of your readiness probe to a bigger value (like a few minutes). Your deployment time will increase, but you will be able to tell if it is due to your readiness check.
Be sure also that your application is not terminating too aggressively when asked to shutdown, and it properly terminates in-fly requests before terminating.