Transport dumpster is a feature built into Exchange Server 2010 HUB transport role and designed to minimize data loss during mail delivery to a DAG in a lossy failover scenario. The transport dumpster is stored inside the mail.que file. 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.
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.
Understanding Shadow Redundancy
http://technet.microsoft.com/en-us/library/dd351027.aspx
Shadow Redundancy Mail Flow Scenarios
http://technet.microsoft.com/en-us/library/dd351091.aspx
For Dumpster: The recommendation is that this be set to 1.5 times the maximum message size limit within your environment. The default value for this setting is 18 MB.
By default, shadow messages are discarded automatically after two days.
Configure Shadow Redundancy
http://technet.microsoft.com/en-us/library/dd351046.aspx
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.
Understanding Shadow Redundancy
http://technet.microsoft.com/en-us/library/dd351027.aspx
Shadow Redundancy Mail Flow Scenarios
http://technet.microsoft.com/en-us/library/dd351091.aspx
For Dumpster: The recommendation is that this be set to 1.5 times the maximum message size limit within your environment. The default value for this setting is 18 MB.
By default, shadow messages are discarded automatically after two days.
Configure Shadow Redundancy
http://technet.microsoft.com/en-us/library/dd351046.aspx
This is basically copied from various sources but doesn't answer the question of why both.
ReplyDeleteDoes not answer the question. Line by line copied from:
ReplyDeletehttps://social.technet.microsoft.com/Forums/en-US/853099df-15c8-41bf-88de-538ba5751ac4/transport-dumpster-and-shadow-redundancy-why-both?forum=exchangesvrsecuremessaginglegacy
https://blogs.technet.microsoft.com/jribeiro/2009/09/28/understanding-exchange-2010-shadow-redundancy/
ReplyDelete