Configure Shadow Redundancy

Applies to: Exchange Server 2010

Shadow redundancy in Microsoft Exchange Server 2010 provides a high availability mechanism for messages for the entire time they're in transit. To learn more about shadow redundancy, see Understanding Shadow Redundancy. You can use the Shell to configure shadow redundancy in your organization.

Looking for other management tasks related to transport servers? Check out Managing Transport Servers.

What Do You Want to Do?

• Use the Shell to enable or disable shadow redundancy
• Use the Shell to configure the shadow redundancy heartbeat
• Use the Shell to configure the maximum age for shadow messages
• Use the Shell to configure the maximum acknowledgement delay on a Receive connector

Use the Shell to enable or disable shadow redundancy

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Shadow redundancy" entry in the Transport Permissions topic.

Use the ShadowRedundancyEnabled parameter of the Set-TransportConfig cmdlet to enable or disable shadow redundancy in your organization. By default, shadow redundancy is enabled.

This example enables shadow redundancy for your organization.

Set-TransportConfig -ShadowRedundancyEnabled $true

For detailed syntax and parameter information, see Set-TransportConfig.

Use the Shell to configure the shadow redundancy heartbeat

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Shadow redundancy" entry in the Transport Permissions topic.

Use the ShadowHearbeatTimeoutInterval and ShadowHearbeatRetryCount parameters of the Set-TransportConfig cmdlet to configure the shadow redundancy heartbeat in your organization. The default value for the shadow redundancy time-out interval is 5 minutes, and the default value for the shadow redundancy heartbeat retry count is 3. On each transport server running Exchange 2010, the shadow redundancy heartbeat is used to determine the availability of the other Exchange 2010 transport servers. For more information, see "Heartbeat" in Understanding Shadow Redundancy.

Assume that because there are unreliable network connections between your Active Directory sites, you want to increase the total time transport servers wait before determining that a remote server is unavailable. To do this, the Hub Transport servers make at least five connection attempts before determining that a server is unavailable, and the servers wait 6 minutes before each connection attempt. As a result, you increase the maximum time for detecting a failure from the default value of 15 minutes (5 minute time-out interval × 3 retries) to 30 minutes (6 minute time-out interval × 5 retries). This example makes the following changes to the shadow redundancy heartbeat configuration:

• Increases the heartbeat retry count to 5.
• Increases the heartbeat time-out interval to 6 minutes.

Set-TransportConfig -ShadowHeartbeatTimeoutInterval 00:06:00 -ShadowHeartbeatRetryCount 5

For detailed syntax and parameter information, see Set-TransportConfig.

Use the Shell to configure the maximum age for shadow messages

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Shadow redundancy" entry in the Transport Permissions topic.

Use the ShadowMessageAutoDiscardInterval parameter of the Set-TransportConfig cmdlet to configure the maximum age for shadow messages in your organization. By default, shadow messages are discarded automatically after two days.

Assume that due to the hardware constraints on your servers, you don't want to retain shadow copies for messages that are delayed. This example reduces the retention period of shadow messages to four hours for your organization.

Set-TransportConfig -ShadowMessageAutoDiscardInterval 04:00:00

For detailed syntax and parameter information, see Set-TransportConfig.

Use the Shell to configure the maximum acknowledgement delay on a Receive connector

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Receive connectors" entry in the Transport Permissions topic.

Use the MaxAcknowledgementDelay parameter of the Set-ReceiveConnector cmdlet to configure how long the Receive connector delays SMTP acknowledgement when receiving messages from systems that don't support shadow redundancy. By default, Receive connectors delay acknowledgement up to 30 seconds. For more information, see "Delayed Acknowledgement" in Understanding Shadow Redundancy.

Example 1

Assume that you have a proprietary application that sends SMTP messages using your Exchange infrastructure. If the rate of message delivery for messages generated by this application is more important than reliability of message delivery, you may want to disable delayed acknowledgement on the Receive connector that receives messages from this application. This example sets the maximum acknowledgement delay to zero on the Receive connector Custom App Receive Connector.

Set-ReceiveConnector "Custom App Receive Connector" -MaxAcknowledgementDelay 0

For detailed syntax and parameter information, see Set-ReceiveConnector.

Example 2

Assume that all messages are typically delivered within 20 seconds in your environment, but due to performance requirements, you don't want to delay acknowledgement more than 15 seconds for messages received from the Internet. After analyzing the message flow, you conclude that 95 percent of messages are delivered within the 15 second interval. This example configures the Receive connector from the Internet to delay acknowledgement for only 15 seconds. In this scenario, your environment provides shadow redundancy for 95 percent of messages received from the Internet.

Set-ReceiveConnector "From the Internet" -MaxAcknowledgementDelay 00:00:15.

For detailed syntax and parameter information, see Set-ReceiveConnector.