Microsoft
Microsoft
I'm quite familiar with the use of the IsExcludedFromServingHierarchy. Its really an influencer for AutoDiscover responses.
however, what i have seen very recently is with a large customer. They have several TB of PF data and in the process more than 100 PF mailboxes were needed to distribute data. Our guidance has been to wait until all the PF mailboxes have received a copy of the hierarchy before doing any content sync actions.
What was observed was that the 100 hierarchy serving mailboxes received a copy of the hierarchy as expected and and normally seen, but the mailboxes marked as not-serving never received a full copy of the hierarchy. The non-serving mailbox had *some* folders, likely only the folders that were assigned to that mailbox. So, customer flip-flopped the hierarchy serving values between the 2 states and once done the mailboxes without a copy of the hierarchy started to sync. Separate testing shows me that this is not exclusive to a large deployment. Even a deployment with only a dozen mailboxes shows the same behavior if some of the mailboxes are excluded from serving the hierarchy. The mailboxes initially set to not serve the hierarchy also seemed to report IsHierarchyReady as False until the switch-a-roo was performed.
This seems to be a different behavior than what i have previously experienced.
So, it goes back to my question about expectations? Should all PF mailboxes have a copy of the hierarchy? I think so, especially since it is possible to statically set the DefaultPublicFolder mailbox of any user to any of the PF mailboxes, regardless of the hierarchy serving flag.
Maybe the non-serving mailbox will eventually get the hierarchy, but on a much longer timeline? not sure and looking for more discrete clarity from Microsoft on this aspect.
