Theory question on AD replication

Question

Hello,

...spotted it by chance today:

If " Intrasite replication takes advantage of LAN network speeds by providing replication as soon as changes occur," why does the default intrasite connection objects have the default schedule set to "once per hour"?

Regards,
Michael

https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc775549(v=ws.10)

Answer 1

Hi @Mikhail Firsov

This is the difference between intrasite and intersite replication. Intrasite means the DC in the same AD Site, while intersite is the replication between DCs in different AD sites. In the case of the later, the replication schedule on the site link between the AD sites will be used to define the replication interval between the DCs, this will useRequest-Pull based replication by default. For DCs that are in the same AD Site then notify-pull replication method is used and replication delay\interval is 15 seconds. It is possible to change the replication method used on the site links from request-pull to notify-pull replication and have a 15 second delay between AD sites. This is accomplished by setting the Options attribute on the AD site link object to 1.

https://social.technet.microsoft.com/wiki/contents/articles/16929.set-active-directory-to-use-notify-replication.aspx

Gary.

Answer 2

Hi GaryReynolds,

Thank you for the reply!

"In the case of the later, the replication schedule on the site link between the AD sites will be used to define the replication interval between the DCs" - yes, it will, but I'm asking about intrasite schedule - if the intrasite schedule is 15sec by default why does this fact is not reflected in the intrasite's connection object? Why does it still show "once per hour" instead of "once per 15 seconds"?

Answer 3

"There is no intrasite connection object"
"The screenshot you have above is the AD Site Link properties i.e. intersite."

???

One site, two DCs:

Answer 4

" I'm not able to find any information that confirms how this controls the replication interval,..." - neither am I :(

I think it's just a general connection object that MS created for both types of replication (intra- and inter-) and enabled the Schedule only for the inter-site replication, not bothering to explain that schedule does not have any meaning for the intra-site replication.

Thank you very much for the interesting articles!

Regards,
Michael

Answer 5

GaryReinolds, here's the answer from your latest link:

"Because the change notification results in updates being replicated within the site with little delay, scheduled replication is only needed when the change notification process fails for some reason. Scheduled replication is just a backup."

Thank you very much for your help!!!

P.S. Please repost this paragraph and I'll mark it as the answer!

Regards,
Michael