The WSO2 API Manager comprises the following main components:
|Table of Contents|
Provides an end-user, collaborative Web interface for API providers to publish APIs, share documentation, provision API keys, and gather feedback on API features, quality and usage. The API Publisher is powered by WSO2 Jaggery, WSO2 Governance Registry and WSO2 Identity Server products.
For more information on API Publisher and its functionality, refer to sections API Developer Guide.
Provides an end-user, collaborative Web interface for consumers to self-register, discover API functionality, subscribe to APIs, evaluate them and interact with API publishers. The API Store is powered by WSO2 Jaggery, WSO2 Governance Registry and WSO2 Identity Server products.
For more information on the API Store and its functionality, refer to section Application Developer Guide.
A runtime, back-end component developed using the WSO2 ESB, which is proven for its performance capability. API Gateway secures, protects, manages, and scales API calls. The API gateway is a simple API proxy that intercepts API requests and applies policies such as throttling and security checks. It is also instrumental in gathering API usage statistics. We use a set for of handlers for security validation and throttling purposes in the API Gateway. Upon validation, it passes Web service calls to the actual back-end. If the service call is a token request call, API Gateway passes it directly to the API Key Manager Server to handle it.
You can integrate a monitoring and statistics component to the API Manager without any additional configuration effort. This monitoring component integrates with the WSO2 Business Activity Monitor, which can be deployed separately to analyze events generated by the API manager. For more information, refer to section Monitoring using WSO2 BAM.see Publishing API Runtime Statistics.
Although the API Gateway contains ESB features, it is recommended not to use it for ESB-specific tasks. Use it only for Gateway functionality related to API invocations. For example, if you want to call external services like SAP, use a separate ESB cluster.
APIAuthenticationHandler: Validates the OAuth2 bearer token used to invoke the API. It also determines whether the token is of type
MessageContextvariables as appropriate. To extend the default authentication handler, see Writing a Custom Authentication Handler.
APIThrottleHandler: Throttles requests based on the throttling policy specified by the
policyKeyproperty. Throttling is applied both at the application level as well as subscription level.
APIMgtUsageHandler: Publishes events to BAM for collection and analysis of statistics. This handler only comes to effect if . See Monitoring using WSO2 BAM See Publishing API Runtime Statistics for more information.
APIMgtGoogleAnalyticsTrackingHandler: Publishes events to Google Analytics. This handler only comes into effect if Google analytics tracking is enabled. See for more information.
APIManagerExtensionHandler: Extends the mediation flow of messages passing through the API Gateway. See Adding a Mediation Extension for more information.
API Key Manager
When the API Gateway receives API invocation calls, it similarly contacts the API Key Manager service for verification. This verification call happens every time the Gateway receives an API invocation call if is not enabled at the Gateway level. For this verification, the Gateway passes access token, API, API version to the Key Manager.
- Through a Web service call
- Through a Thrift call
The That the default communication mode protocol of Key Manager is using Thrift but you can change the
WSClient in Thrift. If your setup has a cluster of multiple Key Manager nodes that are fronted by a WSO2 ELB instance for load balancing, change the key management protocol from Thrift to WSClient using the
<KeyValidatorClientType> element in . Thrift uses TCP load balancing and the ELB does not support it.
The following diagram depicts the collaboration of these main components with an easily-integrable monitoring and statistics component.