Given that Microsoft released Exchange 2013 CU1 on April 2, you'd be forgiven in assuming that CU2 will be available for download on July 2. After all, that's what Microsoft's new servicing model for Exchange 2013 implies with its once-a-quarter cadence. But once-a-quarter is not an exact science. At least, not in Redmond (nor for this Redmond either).
Those of you who marked your calendar for July 2 as the likely date for Microsoft to release CU2 will probably be disappointed as there are no signs that Microsoft will release CU2 on this date. This might come as a surprise given the interpretation that most people, including myself, arrived at when Microsoft announced their new servicing strategy for Exchange 2013 last February and said “CU’s will be delivered on a pre-determined schedule four times a year”. Being slightly nerdy, four times a year became “once a quarter” and then “every thirteen weeks”.
Thirteen weeks from CU1’s release on April 2 is July 2, hence the expectation. But then the mild-mannered (sometimes) Scott Schnoll took the opportunity of reminding everyone at TechEd North America that “once a quarter” can actually mean “at any time during a quarter”. In other words, Microsoft could release CU2 at any time during the third quarter of 2013 and they would be in accordance with their stated strategy. Cancel that CU2 installation exercise over the July 4 holiday!
In fact, Scott is dead right and this only goes to prove that humans have a fantastic ability to read anything they want into a piece of text. We shall just have to wait a tad longer for CU2 to appear and deliver the goodness hinted at in strategic leaks given during TechEd sessions. I imagine that a delay will actually come as a blessed relief because it means that companies will have more time to sort out associated issues such as coordinating the testing of a new version of Exchange with other Microsoft products (Lync and SharePoint are regularly updated too) and third-party products, all of which has to be done before CU2 can be deployed into production.
You might wonder why Microsoft doesn’t keep to a neat-and-tidy every-13-weeks schedule. Well, every CU is deployed intodatacenters to be used by Microsoft itself and Exchange Online customers before it is shipped to on-premises customers. As Scott noted during his session “When we think that the update is ready to be deployed, we (Microsoft) will be the first ones to deploy it”. There is much goodness in this approach, I think, because it should help to avoid the kind of quality problems that afflicted some of the Exchange 2010 roll-up updates. After all, if a problem doesn’t surface when used by millions of Office 365 users, there’s a fair chance that it won’t blow up in an on-premises deployment. Nothing is perfect, but this strategy makes sense.
One issue that doesn’t exist for CUs is the requirement to deploy a new version of Exchange to remain secure, something that was a royal pain for many administrators who realized that Exchange 2010 roll-up updates included security updates. Exchange 2013 separates CUs from security updates so that when a security update is released, it is available for all supported versions. In practical terms, this means the current CU and the previous CU (support for a CU is for three months after the release of the latest CU). You still have to perform frequent updates to remain current but the appalling vista of leaving servers potentially unprotected because you are not ready to install an Exchange update is gone.
As summer goes on, we will see CU2 appear. The question is just when. I don’t think it will be in July, but I have been known to be wrong before!
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