AWS migration DNS updates

From NewHaven Software Wiki

Current revision as of 19:41, 9 January 2012

Overview

Distributed DNS service is available at no charge as part of your eCMS hosting. Service is provided through NeuStar, a top-tier, globally distributed DNS service provider (NeuStar UltraDNS) servicing many high-volume websites (including Kelley Blue Book and Forbes.com). This does not affect your domain registration - you still own your domain and have your own contact information listed at your registrar, you simply replace your registrar or ISP's nameservers with the ones provided by us.

Should you decide to run your own DNS servers or contract with another 3rd party (such as your registrar or Internet service provider) to run your DNS, you will need to make the changes below at your provider prior to your site's cloud migration.

Required DNS changes for AWS migration

• NOTE: If your registrar or DNS host offers the option, please set the time-to-live (TTL) value for the record currently pointing to your website to 60 before making the other changes below. This will ensure timely propagation of the other changes once they are made and minimize the site maintenance window during the migration itself. We also recommend leaving this set at 60 until well after the migration is completed.

If your primary domain or www site is hosted at another location, do not perform step 2 below.

1. Create a CNAME record that directs your website to the AWS URL provided to you at the time of migration.
   • Example 1: www.mysite.com CNAME mysite-123456789.us-east-1.elb.amazonaws.com.
   • Example 2: store.mysite.com CNAME mysite-123456789.us-east-1.elb.amazonaws.com.
   • Your eCMS store is load balanced across multiple datacenters and multiple servers using Amazon's Elastic Load Balancing/ELB service. When an ELB is created, a semi-random URL is generated (the numbers will be different than 123456789 but the remainder of the example URLs should be the same). This URL lives for the duration of the ELB's lifetime.
2. Add an A record for your base domain (used for a 301 redirect to the www site).
   • mysite.com A 184.73.175.197
   • Any requests for mysite.com (rather than www.mysite.com) will resolve to 184.73.175.197, which returns a 301 redirect (permanent) to the www site. Since a CNAME cannot exist as a record for a domain's apex record, a redirect is required to forward traffic from the apex domain to the store's primary subdomain.
   • Again, if your eCMS store is not your www site, you most likely do not want to do this. Please contact ecms@newhavensoftware.com if you have questions about this setting.

On the day of your migration

When you schedule your migration with us, if you will continue to manage your own DNS, please send us the contact information for the technical contact who will be making the actual DNS changes. We will put the engineer migrating your site in direct contact with him/her to coordinate.

1. At the scheduled time, CV3 will disable your current site's checkout (with the site maintenance page) to migrate over the last orders and product updates that have not been migrated yet. This process should take only a few minutes.
2. Once this is complete, you will receive an email notification to make the DNS changes outlined above (your technical contact will receive the AWS URL in advance).
3. When the DNS updates have fully propagated (should be very quick if your TTL has been adjusted), all requests will go to the new platform. To check the propagation status, look up your eCMS site name at another DNS server such as Google's public-facing DNS (8.8.8.8 or 8.8.4.4).