Hello :-)

I have a few questions that I hope someone can help me with.

I'm trying to set up streaming notification to detect calendar changes in multiple mailboxes using EWS API 2.0.
Using one connection and one subscription for each mailbox works fine with only a few mailboxes.

I have read about "maintain affinity", and tried to follow the steps from the msdn page regarding this:
I'm supposed to get the GroupingInformation using Autodiscover, and then subscribe each group to separate connections.
This way, I will achieve a reduced number of connections.
At the moment I'm testing with just 4 mailboxes, and when I call Autodiscover to get GroupingInformation, all the 4 mailboxes have different GroupingInformation values, so I will end up with 4 connections and 4 subscriptions.
The ExternalEwsUrl is the same for all mailboxes and the domain is the same.
So my questions are:
1: Why is the GroupingInformation different for each mailbox, and is it anything I can do to change it?
2: If I have 5000 mailboxes, should I go for one connection and one subscription for each mailbox, or should I use "affinity" as described on the msdn page (Maintain affinity)?
3: Is there any other/better options?

Thanks in advance.

• Edited by oyvindkleppe Thursday, July 02, 2015 1:22 PM

I am not much aware about maintain affinity feature that you are talking above.

But I can suggest you a better way to enable auditing on Exchange mailboxes that can be more beneficial while need to detect and get notified for calendar changes in multiple mailboxes. One good application you can have a look at (http://www.exchangeserverauditing.com/) that provides a centralized platform for auditing multiple exchange servers from multiple domains. The tool stores the audit information in a central database and provides an easy-to-understand summary of the audit report.

1. This is due to the way mailboxes are allocated to Mailbox Databases (or Dag's) within the 0365 infrastructure you can use Get-Mailbox and look at the ServerName and Database properties to see where your mailboxes are being hosted but within your tennant you will probably find mailboxes are scattered across multiple datacenters (the first few letters of the servername gives you the DC location). That said you need to evaluate the Grouping information on more then 4 mailboxes to really tell but you should find within 5000 mailboxes you have they will be grouped together just don't execpt it to be sequental and you can't do anything to control the allocation.

2. Use affinty the situation your describing is what its for

3. Keep in mind this is a client API hence the client connection orrientation, with Office365 the Webhooks API is now in preview https://msdn.microsoft.com/en-us/office/office365/api/notify-rest-operations . While its not fully baked yet going forward using the REST api is going to be a better way to go about it as they are designing it with these type of issue in mind.

Cheers
Glen

  

• Marked as answer by oyvindkleppe 20 hours 19 minutes ago

Hi Glen,

Thanks for your reply, and thanks for clearing this up :-)
I'm gonna stick to affinity for now. I will also keep an eye on the REST api as you suggested.., looks promising.

Cheers,
yvind

Hi Andrew,

Thanks for your reply.
I'll keep your suggestion in mind, but for now Glen provided me with the information I was looking for :-)

Cheers,
yvind

1. This is due to the way mailboxes are allocated to Mailbox Databases (or Dag's) within the 0365 infrastructure you can use Get-Mailbox and look at the ServerName and Database properties to see where your mailboxes are being hosted but within your tennant you will probably find mailboxes are scattered across multiple datacenters (the first few letters of the servername gives you the DC location). That said you need to evaluate the Grouping information on more then 4 mailboxes to really tell but you should find within 5000 mailboxes you have they will be grouped together just don't execpt it to be sequental and you can't do anything to control the allocation.

2. Use affinty the situation your describing is what its for

3. Keep in mind this is a client API hence the client connection orrientation, with Office365 the Webhooks API is now in preview https://msdn.microsoft.com/en-us/office/office365/api/notify-rest-operations . While its not fully baked yet going forward using the REST api is going to be a better way to go about it as they are designing it with these type of issue in mind.

Cheers
Glen

  

• Marked as answer by oyvindkleppe Friday, July 03, 2015 11:08 AM