Installing and Configuring a FHIR Server

Configuring an Existing FHIR Server

You can edit the configuration settings of an existing FHIR server using the FHIR Server Management page of the Management Portal. These configuration settings can also be modified programmatically by setting the properties of the server’s ConfigData object.

To edit the configuration settings of an existing FHIR server via the Management Portal FHIR Server Management page:

1. Make sure you are in the FHIR server’s namespace.

2. Navigate to Health > MyNamespace > FHIR Server Management.

3. In the tile for the desired server, open the menu and choose Edit.

4. Fill out the form as follows:

   1. If desired, change the server name in the Name field.

   2. If there are custom packages associated with the selected FHIR version and you want your endpoint to support one of them, select it from the Custom Packages dropdown.

      If this dropdown is not present, there are no custom packages associated with the selected FHIR version.

      For more information about packages, see Profiles and FHIR Adaptations. In particular, for information about managing packages programmatically, see Package APIs.

      Note:

      Enabling a custom package automatically triggers the system to re-index search tables when you save your changes.

   3. Configure the desired settings in the Advanced Configuration area of the dialog, using the following descriptions as a guide.

      Setting	Description
      Data Organization Strategy	If desired, select a different InteractionsStrategy for the endpoint. The default interactions strategy isHS.FHIRServer.Storage.JsonAdvSQL.InteractionsStrategy, which stores FHIR data as JSON in dynamic objects. If you created a custom InteractionsStrategy, it appears in this dropdown and you can select it.
      Resource Database	The database that contains current FHIR resource data. If your FHIR server does not use separate databases, this database also contains previous versions of FHIR resources.
      Resource History Database	If your FHIR server uses separate databases, this database contains previous versions of FHIR resources.
      Default Search Page Size	Search result page size to use when a search does not contain a _count parameter.
      Max Search Page Size	Maximum search result page size to prevent an excessive user-specified page size.
      Max Search Results	Maximum number of resources that can be selected by a search before the server responds to the query with an error. This number only includes resources selected by the actual search; it does not include resources included via an _include search parameter. This value does not affect the size of pages returned by a search. Overly broad searches that select large numbers of resources take a lot of system resources to fulfill, and are probably more broad than the client actually needs.
      Max Conditional Deletes	Maximum allowable number of resources to delete via conditional delete. If the conditional delete search finds more than this number of resources, then the conditional delete as a whole is rejected with an HTTP 412 Precondition Failed error.
      Default Prefer Handling	Specifies what happens by default when a search request contains an unknown parameter. Specify lenient to ignore the unknown parameter and return a bundle in which the OperationOutcome resource identifies the issue. Specify strict to reject the search request and return an error. A FHIR search request that includes the prefer headerOpens in a new tab overrides this default.
      OAuth Client Name	Specifies the application name that the FHIR server, as an OAuth resource server, uses to contact the OAuth 2.0 authorization server when needed. Choose the desired OAuth client name from the dropdown list. For more information about OAuth 2.0 support, see OAuth 2.0 Authorization.
      Service Config Name	To route FHIR requests through an interoperability production before reaching the FHIR server, select the package and name of the business service that will receive the requests. Unless the business service has a custom name, this entry is HS.FHIRServer.Interop.Service. Note: For a business service to appear in this dropdown, it must extend the HS.FHIRServer.Interop.ServiceOpens in a new tab class, and it must be included in an interoperability production in this namespace. For more details, see Interoperability Productions and Adding Business HostsOpens in a new tab.
      FHIR Session Timeout	Maximum number of seconds between requests to the service before any session data is considered stale.
      SMART on FHIR Capabilities	A comma-delimited list of the endpoint’s SMART on FHIR capabilities. This list does not control the functionality of the endpoint; rather, it specifies the capabilities that are returned in the JSON document when a client appends /.well-known/smart-configuration to the endpoint’s URL. For more details about SMART on FHIR capabilities retrieved with Well-Known URIs, see FHIR Authorization Endpoint and Capabilities Discovery using a Well-Known Uniform Resource Identifiers (URIs)Opens in a new tab.
      Silence search parameter indexing errors	Click this checkbox to prevent search parameter indexing errors from aborting FHIR resource Save. CAUTION: Enable this setting only when necessary.

5. When you have finished filling out the form, click Save to save your changes. To start over instead, click Cancel.

If you prefer to use a command-line interface to configure a FHIR server, see Command Line Options.

Resetting a FHIR Server

You can reset a FHIR server. This deletes all data from the server but leaves the server itself intact. Follow these steps to reset a FHIR server:

1. Make sure you are in the FHIR server’s namespace.

2. Navigate to Health > MyNamespace > FHIR Server Management.

3. In the tile for the server associated with the desired endpoint, open the menu and choose Reset.

4. In the Reset FHIR Data dialog, click Execute.

Deleting a FHIR Endpoint

When using the Management Portal to delete a FHIR server endpoint you can choose whether to delete the associated FHIR data or to retain all of its FHIR data. If you prefer, you can use the command line interface instead. For details, see Command Line Options.

To delete an endpoint:

1. Make sure you are in the FHIR server’s namespace.

2. Navigate to Health > MyNamespace > FHIR Server Management.

3. In the tile for the server associated with the desired endpoint, open the menu and choose Delete.

4. Decide whether to remove all data along with the endpoint, and select the corresponding radio button. Deletion options are as follows:

   • Remove all data from the repository, delete the endpoint and fhirserver.

   • Decommission FHIR endpoint, don’t remove data.

5. Click Execute.

Installing Programmatically

For applications that need to install a FHIR server programmatically rather than using the Management Portal, the server must be installed first, then configured.

The FHIR server must run in a foundation namespace, therefore creating a foundation namespace is a prerequisite to installing the FHIR server. Once you have a foundation namespace, the following methods of HS.FHIRServer.InstallerOpens in a new tab must be called in order:

pPackageList Parameter

The pPackageList parameter of the InstallInstance()Opens in a new tab method accepts a list of FHIR packages that have been loaded into the system. Often, a package corresponds to a specific Implementation Guide, but can also be the core metadata for a version of FHIR. By passing a list of packages to InstallInstance, you can configure an endpoint to support one or more packages. For more about packages, see Profiles and FHIR Adaptations.

To obtain a list of the packages that can be passed into the pPackageList parameter, use the HS.FHIRMeta.Storage.Package.GetAllPackages()Opens in a new tab method. For example, the following code displays the identifiers of the available packages

 set packages = ##class(HS.FHIRMeta.Storage.Package).GetAllPackages()
 for i=1:1:packages.Count()
   { write packages.GetAt(i).id,! }

The result might look like:

hl7.fhir.r5.core@5.0.0
hl7.fhir.r4.core@4.0.1
hl7.fhir.us.core@3.1.0
hl7.fhir.r3.core@3.0.2

You could then pass in some of these package identifiers as arguments to the pPackageList parameter using $lb. For example:

 Do ##class(HS.FHIRServer.Installer).InstallInstance(
            myURL,
            strategyClass,
            $lb("hl7.fhir.r5.core@5.0.0"))

For details about the APIs used to create FHIR packages, see Package APIs.

Programmatic Install Example

The following ObjectScript code example installs a FHIR server that supports two packages and uses the default storage strategy (Resource Repository).

 Set appKey = "/myfhirserver/fhir/r5"
 Set strategyClass = "HS.FHIRServer.Storage.JsonAdvSQL.InteractionsStrategy"
 Set metadataPackages = $lb("hl7.fhir.r5.core@5.0.0")

 //Install a Foundation namespace and change to it
 Do ##class(HS.Util.Installer.Foundation).Install("FHIRNamespace")
 Set $namespace = "FHIRNamespace"

 // Install elements that are required for a FHIR-enabled namespace
 Do ##class(HS.FHIRServer.Installer).InstallNamespace()

 // Install an instance of a FHIR Service into the current namespace
 Do ##class(HS.FHIRServer.Installer).InstallInstance(appKey, strategyClass, metadataPackages)

Configuring Programmatically

Once you have installed a FHIR server, it can be configured programmatically using the HS.FHIRServer.Installer.UpdateInstance()Opens in a new tab method. This method accepts several arguments that configure the server, including one that accepts the server’s HS.FHIRServer.API.ConfigDataOpens in a new tab object, which contains most of the server’s configuration options. For a list of these configuration options, see the class referenceOpens in a new tab. In addition to the options defined with the ConfigData object, a few of the server’s settings (Service Config Name, OAuth Client Name, and Enabled) are specified using a dedicated parameter of the UpdateInstance() method.

The following code configures an existing FHIR server using the UpdateInstance() method.

 Set appKey = "/fhirendpoint/r5"

 //Get and modify FHIR server's configuration object
 Set strategy = ##class(HS.FHIRServer.API.InteractionsStrategy).GetStrategyForEndpoint(appKey)
 Set configData = strategy.GetServiceConfigData()
 Set configData.DefaultPreferHandling = "strict"
 Set configData.DebugMode = 1
 //stringify configData before updating FHIR Server
 Set jsonConfigData = configData.AsJSONString()

 // Define additional settings
 Set enabled = 1
 Set serviceConfigName = "HS.InteropPackage.myBusinessService"
 Set oAuthClient = "OAuthClientName"
 
 // Update FHIR Server
 Do ##class(HS.FHIRServer.Installer).UpdateInstance(appKey, jsonConfigData, enabled, serviceConfigName, oAuthClient)

Command Line Options

Developers who prefer a command line interface to the Management Portal can use Console Setup in the InterSystems Terminal to perform many of the same actions that are available in the user interface. To run the Console Setup, open the InterSystems Terminal and run:

 do ##class(HS.FHIRServer.ConsoleSetup).Setup()

The following sections describe each option that is available in the Console Setup.

Configuring the Profile Validation Server

When you create a FHIR endpoint, an external server named FHIR_Validation_Server is created to perform back-end functions related to profile validation. This server requires a Java 11 development kit. If your JAVA_HOME environment variable does not point to a Java 11 directory, you can use the Management Portal as follows:

1. If necessary, install a supported Java 11 JDKOpens in a new tab. Make a note of the directory where it has been installed.

2. In the Management Portal, navigate to System Administration > Configuration > Connectivity > External Language Servers.

3. If the FHIR_Validation_Server is running, click Stop.

4. Enter edit mode by clicking FHIR_Validation_Server.

5. On the Edit External Language Server page, in the Java Home Directory fieldOpens in a new tab, enter the path to your Java 11 directory.

6. Click Save.

7. Restart the FHIR_Validation_Server by clicking Start.

8. To ensure good performance when you execute validation operations related to previously-imported profiles (including those that are automatically imported), in the Terminal application, switch to your FHIR-enabled namespaceOpens in a new tab and execute the following command:

   do ##class(HS.FHIRServer.Installer).InitializeProfileValidator()
   

   

Optimizing Search Performance

For a FHIR server which uses or extends the Resource Repository, you can optimize the performance of search interaction responses by running the Tune Table utility on the SQL search tables generated for that endpoint. By default, the names of these tables begin with HSFHIR. You can also set custom selectivity values for these tables manually.

When you install a new FHIR server which uses or extends the Resource Repository, a set of default selectivity values are assigned to searchable elements based on the element’s data type. These default selectivity values allow the server to select more efficient query plans when it retrieves resources in response to a search request. Selecting prospective results by beginning with the most selective query parameter minimizes the number of resources each subsequent selection operation must evaluate.

For example, consider the following search request:

GET [base]/Patient?family=halifax&gender=male

Probably, the Resource Repository contains fewer patients with the family name Halifax than patients who are male. Therefore, it is probably most efficient to find the Patients with the family name Halifax first, because then the operation to find males will only have to search through the small subset of patients named Halifax.

If you have upgraded to this version from a version prior to 2023.1 and you are using a preexisting FHIR server, you can set these default selectivity values for your search operations using the SetDefaultSearchTableSelectivities()Opens in a new tab method. Invoke this method in the Terminal, providing the relative path for your FHIR endpoint, as in the following example:

do ##class(HS.FHIRServer.Storage.SearchTableBuilder).SetDefaultSearchTableSelectivities("/csp/healthshare/hsods/fhir/r5")

However, for most preexisting FHIR servers, selectivity values generated by Tune Table are more useful than the default selectivity values set by this method.