Exchange 2007 introduces new high availability feature which is the cluster continuous replication (CCR), CCR is a combination of an Active/Passive Exchange cluster and Asynchronous log shipping for replicating the log files contents to the passive node. let's explain more, In Exchange 2003 we bring high availability on the server/service layer by implementing for example a two nodes cluster where by the passive node will take ownership on the cluster in case of a failure in the Active node thus providing service continuity to our customers however we didn't provide an out of the box solution to provide resiliency on the database level so if you have a failure on the database level you will lose your messaging services as both nodes will not be able to help you and you have to either recover or restore your databases.

Exchange 2007 CCR brings the HA features of an Exchange cluster plus providing another high availability layer on the database level by seeding another copy of the Exchange databases to the other node which will be on another disks or may be a complete different storage, should you faced a problem in the database on the active node you can switch to the passive node which is having another copy of the database. CCR can be used to provide a complete HA messaging solution in one data center or it can be used in two sites to bring you site resiliency features also. knowing the fact CCR brings you also other benefits such as having your VSS backup from the passive node using the CCR database copy plus you can reduce your backup media overhead and others, there is some requirements and limitations such as you can't have more than 1 store in the storage group and definitely for hosting the two nodes in different sites you should have a decent bandwidth between the two sites plus stretching the IP subnet's between both of them and others that you can check this URL for these requirements http://technet.microsoft.com/en-us/library/bb124521.aspx

Looking to the CCR log shipping, what CCR is doing is asynchronously copying using SMB the Exchange transactions logs after being closed "1 MB each" to the other node, the other node do a corruption check on the log file and commit it to the store bringing it to a matching state with the active node. However looking into a situation where by the active node can have a problem and the passive node will take ownership on the CCR while there is few transactions that can be 1 or 2 log files that was not yet replicated or committed to the passive node so the users will actually ends up by having few emails missing or may be 2-3 large emails. Here comes the Transport Dumpster role, by default when you configure the CCR the hub enable the transport dumpster feature on itself where by it will queue & store the last email transactions "settings is configurable such as total size, duration, etc... via power shell", should the passive node changed to be active the Hub automatically delivers the last transactions in the dumpster to the users mailboxes on that server, mailbox will delete whatever emails exists and commit whatever missing emails so bringing the store to a Sync situation. GREAT

note that dumpster will not bring you the following:

1. Drafts folder for Outlook clients in online mode
2. Appointments, contact updates, tasks & its updates
3. Outgoing mail that is in transit from the client to the Hub where there is a time which e-mail message only exists on the sender's mailbox server

I like CCR...

We have released our Exchange 2007 storage calculator, get the calculator and the full article at the Exchange team blog  http://msexchangeteam.com/archive/2007/01/15/432207.aspx

Copied from the Exchange team blog.

Today, Microsoft publicly announced its new set of tools to make the transition from Lotus to Microsoft easier.  The announcement details:

• A new set of coexistence and migration tools (Microsoft's Transporter Suite 2007 for Lotus Domino)
• Role-Based Templates for SharePoint My Site: Specific application templates based on common roles like sales managers, IT engineer, etc.
• 40 Windows SharePoint Services 3.0 Application Templates: Providing a great starting point for many custom applications.

  (* you can read the whole Press Release here )

As part of this we are opening up a public beta for the Transporter Suite for Lotus Domino for anyone interested to download, trial and provide feedback. The beta program is being run through Microsoft Connect at http://connect.microsoft.com.  To access the Beta simply signup for Connect and select to apply for 'Microsoft Transporter Public Beta' under the programs in 'Available Connections'.

Great day for customers who are deploying Microsoft's collaboration products:

The Transporter Suite is a huge step forward at making transitions easier.  We look at this release from several points: 

• 2007 collaboration: We fully support Microsoft's 2007 product line.  All our tools are designed for Exchange 2007, Office 2007 and SharePoint 2007 - enabling customers to migrate to the latest and greatest collaboration software available.
• New features: We added a ton of new features (like a unified admin GUI, PowerShell foundation, ACL migrations, User migrations, scripting, multi-threading, and more) that ease the migrations for our customers migrating accounts, mailboxes, applications and doing analysis.
• Enabling future scenarios: We built the suite as a platform that we are now using to add additional scenarios for future releases.  Including the support for custom application migration, local archive migration, encrypted mail migrations, personal address books and more.   We are also working closely with partners to extend even further...
• Endless possibilities and customization: our new tools are setting a new coexistence & migration direction for our customers and partners to expedite their migrations.  Being built on PowerShell, there is nothing they can not do!!!

Check out the cool video on Channel 9:  http://channel9.msdn.com/go/mscolab/transporter !!!

There will be lots of additional information, some Live Meeting demo's showcasing the extensibility of our tools for customers and partners & more. 

All of this starts today & will be happening later this week and more... keep on checking the CollabTools blog too!