70-663 · Question #165
A corporate environment includes Exchange Server 2010 SP1. The Exchange Server environment includes two Client Access servers, two Hub Transport servers, and two Mailbox servers on the internal…
The correct answer is A. Enable shadow redundancy. Understanding Shadow Redundancy Applies to: Exchange Server 2010 SP2 High availability strategies for Exchange have focused on the availability and recoverability of data stored in mailbox databases. When you implement a highly available solution for your Mailbox servers, the…
Question
A corporate environment includes Exchange Server 2010 SP1. The Exchange Server environment includes two Client Access servers, two Hub Transport servers, and two Mailbox servers on the internal network, and two Edge Transport servers in a perimeter network. An edge subscription is in place between the Hub Transport servers and the Edge Transport servers. When an Edge Transport server fails, messages accepted by that server are not delivered. You need to recommend a solution for ensuring that messages accepted by either Edge Transport server are attempted for delivery if either Edge Transport server fails. What should you recommend?
Options
- AEnable shadow redundancy.
- BCreate a new remote domain.
- CCreate a new send connector.
- DEnable back pressure.
How the community answered
(38 responses)- A76% (29)
- B8% (3)
- C3% (1)
- D13% (5)
Explanation
Understanding Shadow Redundancy Applies to: Exchange Server 2010 SP2 High availability strategies for Exchange have focused on the availability and recoverability of data stored in mailbox databases. When you implement a highly available solution for your Mailbox servers, the e-mail messages won't be lost, and they can easily be recovered after a failure, after they arrive in a mailbox. However, these strategies didn't extend to messages while they're in transit. If a Hub Transport server fails while processing messages and can't be recovered, data loss could occur. As the volume of messages processed by Hub Transport servers increases, potential data loss becomes an increasing concern for administrators. Microsoft Exchange Server 2007 introduced the transport dumpster feature for the Hub Transport An Exchange 2007 Hub Transport server maintains a queue of messages delivered recently to recipients whose mailboxes are on a clustered mailbox server. When a failover is experienced, the clustered mailbox server automatically requests every Hub Transport server in the Active Directory site to resubmit mail from the transport dumpster queue. This prevents mail from being lost during the time taken for the cluster to fail over. While this does provide a basic level of transport redundancy, it's only available for message delivery in a cluster continuous replication (CCR) environment and doesn't address potential message loss when messages are in transit between Hub Transport and Edge Transport servers. Exchange Server 2010 introduces the shadow redundancy feature to provide redundancy for messages for the entire time they're in transit. The solution involves a technique similar to the transport dumpster. With shadow redundancy, the deletion of a message from the transport databases is delayed until the transport server verifies that all of the next hops for that message have completed delivery. If any of the next hops fail before reporting back successful delivery, the message is resubmitted for delivery to that next hop. Shadow redundancy provides the following It eliminates the reliance on the state of any specific Hub Transport or Edge Transport server. As long as redundant message paths exist in your routing topology, any transport server becomes disposable. If a transport server fails, you can remove it from production without emptying its queues or losing If you want to upgrade a Hub Transport or Edge Transport server, you can bring that server offline at any time without the risk of losing messages. It eliminates the need for storage hardware redundancy for transport servers. It consumes less bandwidth than creating duplicate copies of messages on multiple servers. The only additional network traffic generated with shadow redundancy is the exchange of discard status between transport servers. Discard status is the information each transport server maintains. It indicates when a message is ready to be discarded from the transport database. It provides resilience and simplifies recovery from a transport server failure. Shadow redundancy is implemented by extending the SMTP service. The service extensions allow SMTP hosts to negotiate shadow redundancy support and exchange discard status for shadow messages.
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