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

EDIT: Updated on 3/6/2018

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 2016 CU (Cumulative Update) 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 SP's (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 :

  • CU’s, 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 CU’s 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 now place the latest CU per mainstream supported baseline on Download Center, just as is done for Service Packs.
  • Additionally, all CU’s are placed into the Windows Update Catalog, WSUS, and offered as an optional Microsoft Update to facilitate acquisition and distribution.
  • On Demand hotfixes are also now placed on the Download Center as well, with CSS providing individual links to customers requesting the hotfix. All hotfixes continue to roll into the next scheduled CU.
  • To reduce friction, downloading CU’s from the will not require providing/receiving an email and URL.

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 KB’s 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: CU s released prior to January 2016 are only available for download from the hotfix sever.

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