Announcing updates to the SQL Server Incremental Servicing Model (ISM)

Updates to Cumulative Update Messaging and Guidance:

Over the years, as we released CUs (Cumulative Updates), you have become familiar with a certain type of deterrent messaging around those updates. Examples like the below messages often lead DBA’s to plan for a deployment of a certain CU, only if and when they hit an issue.

  • “This cumulative package is intended to correct only the problems that are described in this article. Apply it only to systems that are experiencing these specific problems.”
  • “A supported cumulative update package is now available from Microsoft. However, it is intended to correct only the problems that are described in this article.”

By then, the system may already be experiencing performance degradation or even service disruption in some cases. This results in a poor experience with SQL Server, where DBA’s face unnerving times to restore service to its optimal state as soon as possible, often by enlisting the assistance of Microsoft CSS (Customer Support Services).

As of January CU releases, these caution messages have been updated, we now recommend ongoing, proactive installation of CU’s as they become available. You should plan to install a CU with the same level of confidence you plan to install SPs (Service Packs) as they are released. This is because CU’s are certified and tested to the level of SP’s. Also, Microsoft CSS data indicates that a significant percentage of customer issues are often previously addressed in a released CU, but not applied proactively.  More so, CU’s contain added value over and above hotfixes. These also may contain supportability, logging, and reliability updates enhancing the overall experience.

In addition to messaging and guidance updates, we have made updates to the CU acquisition model.

Acquisition changes:

  • CUs, of course, have traditionally been made available on the “Hotfix” server (accompanied by the “cautionary language” associated with a ‘QFE’ or ‘Hotfix’). The inconsistency here is that CUs are not really simple quick hotfixes anymore.  The encompassed updates are well tested at individual as well as full system integration levels today.
  • Therefore, we are now placing the latest CU per mainstream supported baseline (2012 SP2/SP3 and 2014 RTM/SP1 today) on, just as is done for Service Packs today
  • Additionally, we will soon release, and maintain, all CUs into the Windows Update Catalog to facilitate acquisition and distribution
  • Only interim CU ‘On-Demand’ fixes will be placed on the hotfix server moving forward
  • To reduce friction, downloading CUs from the will not require providing/receiving an email and URL
  • We are also evaluating offering the latest CU as an Optional update on Microsoft Update, just like Service Packs today

EXAMPLE: When SQL Server 2014 SP1 ‘CU9’ is released, CU9 will replace ‘CU8’ on the download center as the latest CU for 2014 SP1.  Adding to the example, while an individual issue may have been originally addressed in ‘CU8’, CU KBs will always point to the latest CU (on the download center), which will then be CU9. Clicking on the “A fix is available for this issue” link in the CU8 KB would take you to the CU9 (latest) download.

Note: Previously released CUs will still be available for download from the Windows Update Catalog or the hotfix sever for CUs released prior to January 2016. CUs will be posted to the Windows Update Catalog within two months after its release to Microsoft Downloads.

We hope these changes will drive more proactive, informed, confident, and simplified CU adoption. Updates reflecting this change to various MSDN and Knowledge Base articles are rolling out now.

SQL Server Tiger Team