When we are moving our site from one host to another then we can face some downtime. One of the trick to minimize the downtime is to reduce the TTL value of our domain to as low as possible like 5 minutes. Every Domain Registrar company has a default value of TTL value. It could be one hour, 12 hours or one day.
What is TTL Value:
TTL stands for Time to Live. All DNS records have a TTL (Time To Live property), which “decides” the maximum amount of time other DNS servers and applications should cache the DNS record. The longer the TTL value is set, More time the DNS servers will take to update their DNS records all over the world. But while moving our webhost we want the DNS change to propagate as fast as possible. So we need to set a shorter TTL value so that Domain Propagation is fast and thus minimum downtime for the Site. Ideally we should change the TTL value one day before changing the Name Server Records to New host.
For Changing TTL value in Godaddy:
1. Go to Domain Manager and Select the Domain for which you want to change the TTL value.
2. At the top of the Page, Click on Tools->DNS Manager
3. In the New window, Click on Edit Zone (written below the domain name)
4. In the New window, The First Option is “Host” and at this place you can edit your TTL value to half hour. The least possible time for Godaddy TTL value is 30 minutes only.
5. Bring your mouse to the line below Host field (the line that starts with @ sign)
and you will be shown a option to edit your TTL value. Edit the TTL value and save the changes.
Few points while changing TTL value.
1. Once you have moved your site to new host successfully, then after 24 hours you can change the TTL value to default value. As Shorter TTLs can cause heavier loads on an authoritative nameserver.
2. WordPress Blogger can consider putting their site in Read only mode while moving the webhost.
3. TTL value is count in seconds. A TTL value of 86400 seconds (or 24 hours) would mean that, if a DNS record was changed on the authoritative nameserver, Then DNS servers around the world could still be showing the old value from their cache for up to 24 hours after the change.