Sql server initialize

[reubenelder]

Hi,

We use the OSS Fhir server and are just working through and improving our upgrade process. According to the documentation for production we should use the schema-manager tool for upgrading the database schema. This seems to work nicely however I just have a couple of questions.

Do we need to have the SqlServer:Initialize flag set to true if we upgrade the schema via the tool - what exactly does this flag do (in the code it says it brings the schema to the minimum supported version - but won't the tool do that)?

And based on the documentation we update the website code first and then update the schema. I presume this means that website updates are backwards compatible with previous versions of the schema, is that correct (i.e. in between web updates and schema updates)?

Thanks for your help,
Reuben

AB#104793

[reubenelder]

Hi, just wondering if anyone has some advice on this? thanks

[EXPEkesheth]

@apurvabhaleMS - Can you please help with questions above?

[apurvabhaleMS]

If SqlServer:Initialize flag set to true then the database will be created and base schema will be applied depending upon other flag settings when running the FHIR service. If database is already created and if Initialize flag is set to true along with AutomaticUpdatesEnabled then on restart of the service the latest schema will be applied.

Database exists and Schema upgrade via service
Initialize = true
AutomaticUpdatesEnabled = true

Database exists and Schema upgrade via schema-manager tool
Initialize = true/false (Not considered)
AutomaticUpdatesEnabled = false

Our code is generally backward compatible. If we are releasing any breaking change then we update the SchemaVersionConstant.Min value. This indicates that SchemaVersionConstant.Min schema version is required to run the FHIR service.

[reubenelder]

Excellent - thanks very much for the info. Much appreciated.

[reubenelder]

@apurvabhaleMS just a quick follow up on this - in a lot of the recent releases the min and max in the SchemaVersionConstant file are the same. If that is the case how can you update with the schema update tool, which if I understand correctly requires the website to be updated first which presumably won't work because the schema hasn't been updated and it is looking for that minimum version?

[EXPEkesheth]

@reubenelder - Yes you will be needed to deploy the schema script prior to deploying the latest FHIR OSS code. This should help address the concern for now. We are working on documenting the guidance. Once we have it documented, will inform.

[reubenelder]

thanks @EXPEkesheth - how exactly do you do that as my understanding is that the upgrade tool gets the schema update scripts from the website? And if you update the schema first, will the website still work before it is upgraded?

[EXPEkesheth]

@reubenelder - The schema scripts are now embedded in the FHIR Schema Manager tool (Reference: fhir-server/src/Microsoft.Health.Fhir.SchemaManager at main · microsoft/fhir-server (github.com)).

[reubenelder]

Excellent - thanks @EXPEkesheth . And if we update the database schema will the FHIR OSS service be able to handle the new schema updates before it is updated? i.e. it sounds like we update the schema and then update the container image. Just wanting to make sure that everything will work while the schema is being updated before the OSS image is updated.

[EXPEkesheth]

@reubenelder -Schema first should work . Can you please provide us the schema version and code version you are on? This will help us with responding concretely.

[reubenelder]

thanks @EXPEkesheth - currently we are on 3.4.214 and schema version 58. Our current upgrade process is to go one release version at a time when upgrading.

[EXPEkesheth]

@reubenelder Your current FHIR version and Schema version is in Sync. Note we are actively making changes which would be backward compatible with the code like how it was in the past.

[EXPEkesheth]

@reubenelder - Closing the issue as it answered. We would like to invite you to participate in FHIR service usage poll : #3504, please provide your input.