We need to change our Google cloud SQL instance from db-g1-small to db-n1-standard-1. Can I change it with zero downtime?
Edit 1
I think I found the answer. It seems that it will take a few seconds of downtime.
You can change an instance's tier at any time, with just a few seconds of downtime.
https://cloud.google.com/sql/pricing
Edit 2
I tried it on our dev env. The downtime was about 10 sec.
while true; date; do curl https://api.xxx.com/v1/items; echo ""; sleep 1s; done
2016/8/29 16:24:50 JST
{"OK"}
2016/8/29 16:24:51 JST
Error
2016/8/29 16:25:01 JST
{"OK"}