Solved

Exchange 2010 Hub/Edge redundancy

Posted on 2011-09-17
9
1,119 Views
Last Modified: 2012-05-12
In exchange 2010, there is a redundancy in Mailboxes database through DAG. if one MB server fails the other MB servers will be the active.

What about the HUB servers, if we put 2 Hubs how do they share their mail.que DB ? the same for edge servers, if one of the Edge servers fails ?

Thanks
0
Comment
Question by:jskfan
9 Comments
 
LVL 37

Accepted Solution

by:
Neil Russell earned 250 total points
ID: 36553341
From: http://technet.microsoft.com/en-us/library/dd638137.aspx#HA


High Availability for Non-Mailbox Server Roles

High availability for the Hub Transport, Edge Transport, Client Access, and Unified Messaging server roles is achieved through a combination of server redundancy, load balancing, and Domain Name System (DNS) round robin, as well as proactive server, service, and infrastructure management. In general, you can achieve high availability for the Client Access, Hub Transport, Edge Transport, and Unified Messaging server roles by using the following strategies and technologies:

Edge Transport   You can deploy multiple Edge Transport servers and use multiple DNS MX resource records to load balance activity across those servers. You can also use Network Load Balancing (NLB) to provide load balancing and high availability for Edge Transport servers.

Client Access   You can use NLB or a third-party hardware-based network load balancing device for Client Access server high availability.

Hub Transport   You can deploy multiple Hub Transport servers for internal transport high availability. Resiliency has been designed into the Hub Transport server role in the following ways:

Hub Transport server to Hub Transport server (intra-organization)   Hub Transport server to Hub Transport server communication inside an organization automatically load balances between available Hub Transport servers in the target Active Directory site.

Mailbox server to Hub Transport server (intra-Active Directory site)   The Microsoft Exchange Mail Submission service on Mailbox servers automatically load balances between all available Hub Transport servers in the same Active Directory site.

Unified Messaging server to Hub Transport server   The Unified Messaging server automatically load balances connections between all available Hub Transport servers in the same Active Directory site.

Edge Transport server to Hub Transport server   The Edge Transport server automatically load balances inbound SMTP traffic to all Hub Transport servers in the Active Directory site to which the Edge Transport server is subscribed.

For additional redundancy (for example, applications that require an SMTP relay), you can create a DNS record (for example, relay.company.com), assign an IP address, and use a hardware load balancer to redirect that IP address to multiple Hub Transport servers. You can also use NLB for the client connectors on Hub Transport servers. When using a hardware load balancer, you need to confirm that no intra-organization traffic will be crossing the hardware load balancer because intra-organization traffic uses built-in load balancing algorithms (as previously described).

Unified Messaging   Unified Messaging deployments can be made more resilient by deploying multiple Unified Messaging servers where two or more are in a single dial plan. The Voice over IP (VoIP) gateways supported by Unified Messaging can be configured to route calls to Unified Messaging servers in a round-robin fashion. In addition, these gateways can retrieve the list of servers for a dial plan from DNS. In either case, the VoIP gateways will present a call to a Unified Messaging server and if the call isn't accepted, the call will be presented to another server, providing redundancy at the time the call is established.

0
 
LVL 15

Assisted Solution

by:It breaks therefore I am
It breaks therefore I am earned 125 total points
ID: 36553388
Hi, we have used hardware load balancing for HT.

http://www.kemptechnologies.com/uk/loadbalancingresource/microsoft-exchange-2010.html

Also like suggested it's worth adding CAS to your redundancy solutions, in Exchange 2010 MAPI clients use the CAS role rather than MB like in 2007. Check out the following article on CAS Arrays.

http://howtoexchange.wordpress.com/2009/12/16/configuring-client-access-array-for-exchange-2010-walkthrough/
0
 

Author Comment

by:jskfan
ID: 36553442
it s not quite what I wanted to know.

let s say we initially had one Hub so there is one hub dumpster database[mail.que], then we added a second one. So even with NLB they won't have the same dumpster DB. in case an active MB database fails while the transaction logs is on the way to the passive MB database, then the passive MB database would not know from which Hub dumpster to pick up the missing record related to the failed T.log



I believe Edge servers, there is not too much of redundancy, since from the beginning they will have to import/export the configuration. I am not sure if we ll have to install anti virus/spam if we need to install it on both Edge servers.
0
Complete VMware vSphere® ESX(i) & Hyper-V Backup

Capture your entire system, including the host, with patented disk imaging integrated with VMware VADP / Microsoft VSS and RCT. RTOs is as low as 15 seconds with Acronis Active Restore™. You can enjoy unlimited P2V/V2V migrations from any source (even from a different hypervisor)

 
LVL 37

Assisted Solution

by:Neil Russell
Neil Russell earned 250 total points
ID: 36553658
As messages do not orriginate on a HT server, there is always a step before the failed HT server. If the HT server fails then it also fails to say "I've sent that message on and it has reached its next "destination". If that is not recieved by the sener then the routing is recaclulated to bypayy the failed HT Server.
No message is cleared from ANY step along the way until the sender knows that the participant it sent to has succefully sent it on itself also.
0
 

Author Comment

by:jskfan
ID: 36553729
the scenario I described is the active MB server has failed while the T.log is on its way to the passive MB. Normally, in this case if there is only one HUb, then the passive MB will ask the HUB to send the  record that s related to the missing T.Log, but when there are 2 Hubs, is the passive MB gonna ask both hubs for the failed log?
I am not sure exactly what all the servers[MB and HUB] are using as protocols in order to recover from any failed T.log between MB databases.
0
 
LVL 49

Assisted Solution

by:Akhater
Akhater earned 125 total points
ID: 36714834
Your Hub servers will never have the same mail.que but the hub servers (and edge) have something called "shadow redundancy", this means that every email routed thru the server will remain in the queue until the server gets the confirmation from the next hop that it was delivered or sent

let's take an example where you have an edge1 -> Hub1 -> Mailbox1

Email is received from Edge1 and delivered to Hub1
Edge1 will NOT delete the email from the queue but will periodically check with Hub1 if Hub1 was able to deliver the email to Mailbox1 or not
when Edge1 gets the acknowledge from Hub1 that the email was delivered to mailbox1 it is then deleted from the queue of edge1.

If edge1 is unable to communicate anymore with Hub1, edge1 will assume that hub1 is down and will reroute the email thru Hub2 (for example)
0
 

Author Closing Comment

by:jskfan
ID: 36813824
THANKS
0

Featured Post

The problems with reply email signatures

Do you wish that you could place an email signature under a reply? Well, unfortunately, you can't. That great Exchange/Office 365 signature you've created will just appear at the bottom of an email chain. What a pain! Is there really no way to solve this? Well, there might be...

Join & Write a Comment

Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
Marketers need statistics and metrics like everybody else needs oxygen. In this article we explain how to enable marketing campaign statistics for Microsoft Exchange mail.
In this video we show how to create a Distribution Group in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >>…
To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…

708 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now