Microsoft’s new cumulative update strategy for Exchange 2013 calls for updates to be shipped to customers every thirteen weeks. An expectation exists, at least on the part of Microsoft, that customers will then install the updates soon afterwards, if only to keep their systems in a supported state.
Delivering updates at a rapid cadence is all very well, assuming that the new software is of a high quality. Regretfully, recent experiences of Exchange 2010 roll-up updates has not been great. And as we look forward to Exchange 2013, a new problem has emerged to reinforce the necessity for quality code.
I was first acquainted with the problem when Kevin O’Brien posted a comment to my post about the new cumulative update strategy. Since then some other evidence has emerged to indicate that the issue is being hit by people who have installed Exchange 2010 SP2 RU6 or Exchange 2010 SP3. You can read posts describing experiences here and here. It does not surprise me that both versions exhibit the same problem as Microsoft has released both recently and the root cause probably lies in an update that’s included in both SP2 RU6 and RU3. It would be surprising if two entirely different bugs caused the same problem.
In a nutshell, it seems like clients working in online mode cannot delete certain items. Outlook clients configured in cached Exchange mode do not exhibit the same problems because delete operations are processed on the client and synchronized back to the server. Evidence suggests that some linkage exists with messages that have PDF attachments, but other indications suggest that this is not the only cause. For instance, it might be possible that messages generated by Cisco Unity voicemail servers are affected too.  The only solution is to deinstall Exchange 2010 SP2 RU6 (or in the case of SP3, either wait for Microsoft to provide a fix or rebuild the server).
This is not a good situation for Exchange to be in. Not only has another quality issue occurred with an update, it seems strange that the problem should be in a fundamental messaging operation like client deletes. This is not an esoteric backroom bug. It’s something that stares users in the face and should have been caught by the massive suite of automated tests that Microsoft uses to validate Exchange builds.
What’s more worrying is that the rapid cadence for Exchange 2013 CU releases might encourage administrators not to test CUs thoroughly before putting new software into production. After all, when you only have thirteen weeks before the next CU is released, something has to give if everything is to be done, including the normal day to day administration required of Exchange servers.
Seeing a new problem emerge in an update released for Exchange is disappointing. No word is yet available from Microsoft as to the root cause or whether we will see Exchange 2010 SP2 RU6-v2 or an updated SP3. The cynics will say that this is par for recent update quality. I sincerely hope that things improve for Exchange 2013.
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