How long does it take for record changes to propagate on all nameservers?

[aa...@turbobytes.com]

Hello,

We care a lot about propagation time for changes to existing records.
We ran a few tests from a few locations to find out how long it takes for Cloud DNS nameservers to start responding with the updated record.
We timed 1.5 minutes on average and we consider this *very long*.

My questions:
- can Google confirm this is the average or median propagation time?
- does Google have plans to reduce propagation time, for example to 10 seconds?

Aaron

[saj...@gmail.com]

Just to clarify, the propagation time here is not taking recursive into account. this is when querying Google Cloud authoritative directly.

[Aaron Peters]

Hey there Google Cloud DNS team,

We'd highly appreciate a response.

The perfect response would be:

"As part of an upcoming release, scheduled for mid Dec, the global record change propagation time will be reduced to approx. 30 seconds."

- Aaron

[Balaji Sampath]

Hi Aaron,

We are working towards sub-min level propagation time, but certainly not in the propagation slots you desired in near term. 

Would you mind sharing the use case that requires you to have <30 seconds propagation?

Thanks

balaji

[Aaron Peters]

Hi Balaji,

Thanks for the response.

Sub-min level propagation sounds good ... much better than the current 2 mins.

The use case is multi-{CDN,cloud,datacenter), where traffic is 'constantly' re-routed based on fresh performance data (RUM).

If a CDN's performance goes bad on AS9143 in The Netherlands, we'll quickly detect that with our RUM measurements, and then we'll want to quickly update DNS record(s).

How quickly end users are actually no longer hitting the bad CDN depends highly on TTL on the CNAME (fully in our control), propagation time (fully in your control) and behaviour of recursive resolvers regarding honouring TTLs.

We currently use two global authoritative DNS providers and want to add a third, or (likely) replace one with Google Cloud DNS.

If you want to connect outside of this forum, feel free to email me at aaron [at] turbobytes com

- Aaron