Schema Registry takes more than ~30s~ 15s to start

[spockz]

When using the docker image (docker.io/confluentinc/cp-schema-registry:7.2.1) of the schema registry it is very slow to start (30s) and start responding, and it requires a significant amount of resources while starting. We need the registry to be alive for some of our tests as the serialisers require the schema registry to present.

I have tested this both on an Apple M1 Pro and on an AMD 5900X. The AMD is slightly faster.

How can we improve the startup time of the registry?

Setup:

• a docker compose with Zookeeper and Kafka running as per the Confluent examples.
• Kafka broker does have TLS enabled
• Apple M1 Pro

Breakdown:

• First 5s seem to be spend in configuring the Schema Registry instance by talking to the schema registry before launching
• The remainder is spent starting up.

Edit: something appears to have changed, the startup time is now 16s. Already better but I'm unsure where this difference comes from. Can we get it further down from 16s?