Update "Integration Services" documentation

docs/en/Audit-Logging.md

@@ -40,12 +40,14 @@ Here, a list of the options you can configure:
 * `HideErrors` (default: `true`): Audit log system hides and write regular [logs](Logging.md) if any error occurs while saving the audit log objects. If saving the audit logs is critical for your system, set this to `false` to throw exception in case of hiding the errors.
 * `IsEnabledForAnonymousUsers` (default: `true`): If you want to write audit logs only for the authenticated users, set this to `false`. If you save audit logs for anonymous users, you will see `null` for `UserId` values for these users.
 * `AlwaysLogOnException` (default: `true`): If you set to true, it always saves the audit log on an exception/error case without checking other options (except `IsEnabled`, which completely disables the audit logging).
+* `IsEnabledForIntegrationService` (default: `false`): Audit Logging is disabled for [integration services](Integration-Services.md) by default. Set this property as `true` to enable it.
 * `IsEnabledForGetRequests` (default: `false`): HTTP GET requests should not make any change in the database normally and audit log system doesn't save audit log objects for GET request. Set this to `true` to enable it also for the GET requests.
-* `DisableLogActionInfo` (default: `false`):If you set to true, Will no longer log `AuditLogActionInfo`.
+* `DisableLogActionInfo` (default: `false`): If you set to true, Will no longer log `AuditLogActionInfo`.
 * `ApplicationName`: If multiple applications saving audit logs into a single database, set this property to your application name, so you can distinguish the logs of different applications.
 * `IgnoredTypes`: A list of `Type`s to be ignored for audit logging. If this is an entity type, changes for this type of entities will not be saved. This list is also used while serializing the action parameters.
 * `EntityHistorySelectors`: A list of selectors those are used to determine if an entity type is selected for saving the entity change. See the section below for details.
 * `Contributors`: A list of `AuditLogContributor` implementations. A contributor is a way of extending the audit log system. See the "Audit Log Contributors" section below.
+* `AlwaysLogSelectors`: A list of selectors to save the audit logs for the matched criteria. 
 
 ### Entity History Selectors
 

docs/en/Integration-Services.md

@@ -1 +1,55 @@
-# Integration Services
+# Integration Services
+
+ABP Framework provides **Integration Services** for inter-module (or inter-microservice) communications. 
+
+**Integration Services** created to distinguish the [application services](Application-Services.md) that are built for inter-module (or inter-microservice) communications from the application services that are intended to be consumed from a UI or a client application.
+
+## Marking an Application Service as Integration Service
+
+You can mark an application service as an integration service by using the `[IntegrationService]` attribute.
+
+Assume that you have an application service named `ProductAppService`, if you want to mark this application service as an integration service, you should use the `[IntegrationService]` attribute top of the application service class:
+
+```csharp
+[IntegrationService]
+public class ProductAppService : ApplicationService, IProductAppService
+{
+    // ...
+}
+```
+
+If your application service has an interface, like `IProductService` in this example, you can use it on the service interface:
+
+```csharp
+[IntegrationService]
+public interface IProductAppService : IApplicationService
+{
+    // ...
+}
+```
+
+## Enabling/Disabling Audit Logging
+
+Audit Logging is disabled by default for integration services but it can be enabled by configuring the `AbpAuditingOptions`:
+
+```csharp
+Configure<AbpAuditingOptions>(options =>
+{
+    options.IsEnabledForIntegrationService = true; //enable audit logging for integration services
+});
+```
+
+* `IsEnabledForIntegrationService` (default: `false`): Disables/enables audit logging for integration services.
+* `AlwaysLogSelectors`: A list of selectors to save the audit logs for the matched criteria. 
+
+Please refer to the [audit logging document](Audit-Logging.md) for other options and details.
+
+## Additional Notes
+
+* Audit Logging is disabled by default for Integration Services but can be enabled by configuring the `AbpAuditingOptions` as mentioned above.
+* If you use the [Auto API Controllers](API/Auto-API-Controllers.md) feature and set an application service as an integration service, URL prefix will be `/integration-api` instead of `/api`. Therefore, you can distinguish internal and external service communications and take additional actions, such as preventing REST API calls for integration services out of API Gateway.
+
+## See Also
+
+* [Application Services](Application-Services.md)
+* [Auto API Controllers](API/Auto-API-Controllers.md)