I had the privilege of attending Microsoft TechEd North America 2010 last week in New Orleans, LA and wanted to share a few confirmed new features of Exchange 2010 SP1 (due out later this year but no firm ETA). The overall theme of this year’s TechEd was centered around, not surprisingly, cloud computing. Specifically, Microsoft emphasized their mature Exchange Online offering but also stressed the growth of Windows Azure (Microsoft’s hosted services platform) and hosted SQL services. The demonstrations of what Windows Azure and hosted SQL could do were extremely interesting and solidified Microsoft’s vision of being “all in” (according to keynote speaker Bob Muglia) with cloud computing.
Regarding Exchange 2010 SP1, a few of the Exchange sessions I attended had specific focus on SP1 and most of the others mentioned how different aspects of Exchange would change with SP1. I discuss a number of my favorite changes/additions associated with SP1 below but please note that there are many more new features. Please refer to the MS Exchange Team blog post on SP1 for more information.
Continuous Replication Block Mode
Continuous Replication Block Mode (CRBM) is, in my opinion, the most interesting and compelling new feature of Exchange 2010 SP1. It is so important that it required a rename of the legacy continuous replication of Exchange 2007/2010 RTM to Continuous Replication File Mode (CRFM). Basically, in CRFM or legacy continuous replication, the unit of replication in Exchange is a single log file. Thus, after each 1 MB log file was closed on the active server (Exchange 2007) or database copy (Exchange 2010), the passive server or database copies would pull that log file and replay into the passive copy of the database. This resulted in a worst case recovery point objective (RPO) of 1 MB (the active log stream) when replication was healthy and up-to-date.
CRBM is a dynamic continuous replication mode that is automatically turned on or off by Exchange 2010 when it detects that replication is completely up-to-date. When turned on, CRBM allows Exchange to ship transactions committed to the active log stream to passive database copies. Thus, the passive copies maintain their own log stream and can significantly reduce the RPO of Exchange in the event of a failure of the active copy. However, while CRBM could bring your RPO down to individual transactions, I wouldn’t recommend advertising an RPO of less than 1 MB to a business owner since you cannot control CRBM and it may be turned off at any time. In my opinion, it is better to advertise 1 MB and indicate that, under healthy replication circumstances, the realized RPO will likely be much better.
CRBM is not synchronous, so Exchange will not wait for an acknowledgement from the passive database copy that the log stream write succeeded. Additionally, since a CRBM passive database copy now maintains its own log stream, it will automatically convert a partial log stream (log fragment) into a full log file for replay in the event of a failure of the active database copy.
Other High Availability and Site Resiliency Improvements
In addition to CRBM, SP1 will bring a number of other high availability and site resiliency improvements. First, Outlook cross-site connection behavior will be more flexible by providing the option to have, in the event of a cross-site database failover, either a direct CAS connection from the CAS Array in the primary data center to the hosting Mailbox server in the secondary data center (default in RTM) or to disable this functionality entirely. Second, Datacenter Activation Coordination (DAC) mode now becomes available for DAGs of all types, not just those with three or more members that are stretched across two or more sites. Finally, improvements in gracefully shutting down log writes when a database activation is initiated removes the need for Exchange to perform a recovery process when a passive copy is activated. This can reduce a typical database activation process from 30 seconds to 15 seconds.
Scott Schnoll at Microsoft has written a great article about these and other high availability and site resiliency changes in SP1 here.
Archiving and Discovery Improvements
As alluded to by Microsoft around when Exchange 2010 RTM was announced, SP1 will allow additional deployment flexibility with the Personal Archive. First, formal support for Outlook 2007 will exist, although it will be limited to basic access to the Personal Archive. Manipulation of retention policies and other aspects of the archive will be limited to Outlook 2010 and OWA 2010. Second, SP1 will now allow storage of the Personal Archive in a different mailbox database than the primary mailbox. Supported combinations of storage are primary and archive in the same mailbox database (on-premises or hosted), primary and archive in different mailbox databases (both on-premises), or primary on-premises and archive hosted. While many law firms may find it difficult to adopt Exchange Online in the near term due to back-end application integration requirements with Exchange, the ability to host some users completely in the cloud and perhaps the Personal Archive for other users in the cloud as well is very intriguing.
Discovery becomes more robust by offering search preview to estimate anticipated discovery searches before executing a query, optional de-duplication of results in a completed discovery, and annotations for discovered content.
Outlook Web App Performance and Personalization Improvements
OWA performance has been improved dramatically in SP1 through a number of enhancements. OWA will now pre-fetch content to make content presentation and reading faster. Additionally, delete, mark as read, and categorization actions will now be asynchronous operations so that their results look instantaneous to the end user. Long running operations, like large file transfers, will no longer be blocking operations that cause OWA hanging from an end user perspective.
OWA themes will make a comeback in SP1, with some prebuilt themes included and the ability to design your own (perhaps to match a corporate color scheme branding, etc.). Furthermore, the administrator can granularly control if/how themes can be used.
Rich Coexistence with Exchange Online
Once Exchange Online is upgraded to Exchange 2010 SP1 later this year, coexistence between an on-premises solution and Exchange Online will become much more robust. Due to the enhanced federated sharing features of Exchange 2010 (calendaring, etc.), traditional coexistence issues associated with free/busy lookups, internal mail classification, etc. are all resolved to provide much more seamless coexistence with Exchange Online. With the ability to easily host and manage a subset of users in the cloud, this rich coexistence model makes this approach much more appealing.
As you can see, Exchange 2010 SP1 will provide many important new features to improve resiliency, flexibility, and performance of Exchange in a number of areas. The SP1 Beta is available now, so check it out!