Planning the steps for going live on Instart services ensures that you have the correct resources available and a roll-back strategy should any issues occur.
Reduce DNS TTL
Reducing the DNS TTL for each in-scope host allows it to refresh more frequently. Taking this step enables your DNS changes to take effect more quickly, and it allows you to roll back more quickly should the need arise.
Instart recommends a DNS TTL of no longer than 10 minutes; shorter is preferable if your DNS infrastructure can sustain the projected load.
DNS TTLs should be changed at least 2 cycles of your existing DNS TTL in advance of launch. For example, if your existing DNS TTL is 24 hours, then you should reduce the TTL at least 48 hours in advance of launch.
Redirecting root to www
Prior to Go-Live, the root domain needs to be redirected to www from the application layer. This ensures that all traffic goes through www and your end users get the benefit of Instart's services.
For example: http://example.com redirected to http://www.example.com
Launching host(s) on Instart requires the existing DNS entry for each in-scope host listed in the table at the top of this document to be overwritten with a new DNS entry.
|IMPORTANT||Note down or otherwise document your current DNS entry setup. This will be critical to quickly rolling back your DNS entries if a rollback is required.|
As previously indicated, be sure to use a low DNS TTL so that rollback can occur quickly should the need arise.
Example 1 HTML Serving Domain:
www.example.com 300 IN CNAME www.example.com.inscname.net.
Example 2 Static Asset Serving Domain:
images.example.com 300 IN CNAME images.example.com.inscname.net.
Please note that the placement of trailing periods is critical.
We recommend that you take the following steps after launching on the Instart service(s):
- Thoroughly test your host(s) immediately following launch using a pre-determined regression test.
- Notify stakeholders and support staff that the change has occurred.
- Once the host(s) are stable, change the DNS TTL back to previous values. This will improve client performance and reduce load on DNS infrastructure.
If you encounter unforeseen complications following launch, it is important to have a clearly-defined rollback process.
To roll back a host, you must overwrite the new DNS entries with the original DNS entries that were in place before the go-live process, as noted during go-live.