My recent post on SLAs prompted some interest and comments from readers so this is a follow-up to that post.
What most people wanted was a list of some SLAs applicable to SQL Server - easier-said-than-done because a lot of SLAs depend on the application being serviced by the database. I had a poke about the web and have pulled together some examples to get you thinking about SLAs you may want to define and strive to meet, listed by category - this is definitely a non-exhaustive list!
Hours of Operation
Some other things to consider are how you define an SLA - for example, in transactions per second or in commit latency that users experience - and the interplay between SLAs - for example, the commit latency SLA may be affected if the acceptable data loss SLA is zero and a solution such as synchronous database mirroring or remote SAN mirroring is used.
Bottom line is that although it can be simple to quickly define and announce a set of SLAs for a given application, its very difficult to make sure that each is palatable to all involved, guarantee that each can be met, and allow easy diagnosis of the system to work out which component is failing when an SLA is not met. SLAs really need to be defined while a sytem is being designed as retro-fitting SLAs after-the-fact can be very time-consuming and costly.
I welcome any comments or observations on this topic - I'll post on this once I get some more feedback.
No sé cuantos de nosotros estamos familiarizados con el término SLA (Service Level Agreement),