Google Cloud SQL proxy randomly crashes
Solution 1:
You need to use the verbose flag to see more details about it. Something like
/cloud_sql_proxy -verbose=true -instances=INSTANCE_CONNECTION_NAME=tcp:3306
Actually, the GCP documentation recommends to capture the output in a log file. "Also, the output from the proxy can help you diagnose connection problems, so it can be helpful to capture in a log file".
In this blog you can find more information about this and useful tips such as how to debugging problems using the Cloud SQL Proxy.