App containers in the same pod start in parallel or according to the order in pod's spec?

When I read the offical doc about init container,there is a sentence:

“init containers offer a mechanism to block or delay app container startup until a set of preconditions are met. Once preconditions are met, all of the app containers in a Pod can start in parallel”.

However when I test a pod with multi app containers,they always start according to the order in pod’s when will the containers start in parallel? or the doc is wrong?

We have historically not specified the startup behavior of app
containers. It might start in serial NOW but we could change it
LATER. Please don’t depend on things that are not specified. If this
doesn’t work for you, we can discuss why :slight_smile: