SQL Server Data Services Sprint 3 now Live
We completed the rollout of Sprint 3 yesterday. The team is already half way into Sprint 4. In Sprint 4 we are focussed on things we need for PDC 2008, which by the way is in late October in Los Angeles. Ray Ozzie and Steve Ballmer foreshadowed some of what this PDC will be all about here and here. You can also go here to see the already announced sessions. SSDS will be a key part of this year's PDC. We set our technical and product agendas that developers care about at PDC. If you want to understand and learn what Services is all about in our Software plus Services strategy, do not miss this year's PDC.
Overall, this was an interesting deployment as we had new environments come online that had to be configured. The team worked really really hard to make the deployment as smooth as possible. Interestingly we did not hit any issues during deployment yesterday. Wish we could video tape how we do this and share with our readers. Something I have to take up with management. I think it will give everyone an appreciation of the amount of planning, tooling, automation and discipline that goes into these deployments.
Anyway as developers, you care about what new things we are enabling. Things have been leaked on this before by Roger, David Robinson and Jeff Currier. But here are the new features:
Blob Support via the REST interface
- In this release, Blobs are limited to 100 megabytes in size.
- Blob Support via the SOAP interface will be delivered in a later update.
Version metadata property has changed from a large integer to a container-wide dbtimestamp value:
- Version numbers are now based on a dbtimestamp and will increase monotonically on a container-wide basis. No two entities in the same container will ever receive the same version value. The dbtimestamp increases monotonically, however not necessarily sequentially. Clients should no longer assume entity version numbers are sequentially assigned. It does not start at 0, but may be any non-zero integer value for a newly created entity.
ETag support via REST, with similar functionality provided on the SOAP interface
- Support for If-Match and If-None-Match via the REST interface. This will allow you to verify that you have the latest version of an Entity, enabling you to use resources more efficiently.
- Support for “Accept” header via the REST interface. This will allow you to denote what content you want returned from the service. For instance when retrieving a Blob, the “Accept” header will allow you to choose between the Blob content, or the metadata properties associated with it.
- Support for ETag semantics on the SOAP service via the new Version Match object on the Scope object.
HEAD support via REST interface
- Support for the “HEAD” verb via the REST interface. This provides a lightweight way of validating existing entity version information without requiring entire entities (or blobs) to be retransmitted to the client.
A new content type – “application/x-ssds+xml” – has been added to the service
- This content type is for storing XML content in the service.
- Existing “application/xml” content type is being phased out in a future sprint.
- The "application/x-ssds+xml" content type should be used for all entities except those containing blob content. Blob entities should instead use a content type value which best reflects the type of blob data stored. It's important to note that the value chosen here will be used later when attempting to retrieve the different parts of an entity by using the "Accept" header.
In addition we did some infrastructure work to enable metering (we will be charging for this service some day :-)) ), throttling (DoS attacks happen and the service needs to work in degraded situation), quota enforcement etc. that developers will not see much of at this time. But once we open our management, debugging and monitoring interfaces, you will be able to plug in and keep up with what is going on with your service.
The primer is updated at our Dev Center here to help you take advantage of the new features. There is one other new "thing" that we are enabling in this rollout that we will talk about a bit later. It is not huge, but it will demonstrate that we are thinking about our building block services very very broadly and deeply. Stay tuned.
