So we are planning to install SSL certificate on our website.
It has taken almost 6 months for google to index our website without the https. Now finally we have some orders coming in.
We had a issue in the past with a different website when we switched to https that google stopped crawling our website.
We are worried that after installing https same will happen.
What is the best possible situation regarding this issue?
We don't really want to wait another 3 to 6 months for google to crawl our site after we update the robots.
We would like to switch to https with minimum disruption with indexing/crawling.
You do not really have many options here because HTTPS is pretty much mandatory for an online store (or even for any website now) because all new Chrome and FireFox browsers show "connection is not secure" warning on any website which is not using HTTPS connection. I do not see how you can run an online store without SSL certificate. Does it mean all your logins and user registrations are not using a secure connection? Not a good idea.
You can find the benefits of running all the pages in your store from a secure connection in my recent article here: Fully Secure Store is not Optional Anymore.
and Google gives a ranking priority to secure sites now so sooner you set it up - sooner you will see the benefits.
I totally agree we don't have any options here.
My main question was to minimize the crawling/indexing downtime when switching to https.
Not much you can do here but we always add redirects in .htaccess so any http:// URL will automatically go to the same https:// URL. And if you do it properly and set everything in your store to run from HTTPS via HTTP/2 protocol with ALPN configured, your store will run faster and Google will be happier and will improve your rankings. We usually get from 30% to 70% in store speed improvement when we switch a client's store to a new setup. Google loves fast and secure stores.