HTTP/2 Server Agent Configuration

To open the HTTP/2 Server agent configuration dialog from a workflow configuration, you can do either one of the following:

double-click the agent icon
select the agent icon and click the Edit button

The Agent Configuration consists of the following tabs:

1 Server Tab
2 Overload Protection Tab
3 OpenAPI Tab
4 5G Tab
5 Authentication Tab

Server Tab

HTTP/2 Server Agent Configuration - Server tab

The Server tab contains the following settings:

Setting	Description

Setting	Description
Settings
Use SSL	Select this option to use the SSL.
Security Profile
Enable 2-way Authentication	If you have selected to use SSL, you can select this option to enable 2-way Authentication. If this option is selected, the Security Profile used must be configured using Java Truststore.
Host	Enter the IP address or hostname that you want the agent to bind to.
Port	Enter the port number you want the agent to bind to.
Request Handling
Default connection concurrent streams	Fundamentally HTTP/2 is designed to make it easy for a client to send multiple parallel requests. Each request is entitled to a thread and if blocking APIs are used, then there are many ways a client can cause that thread to block. To handle the resource problem this can cause, the setting Default connection concurrent streams can be used. The setting specifies the maximum number of concurrently open streams allowed per single HTTP/2 connection. The default value uses in Jetty HTTP/2 server is 128. Larger values increase parallelism, but cost a memory commitment.
Route Error to APL	Select this option if you want to route HTTP errors to APL for custom handling. For more information on how to handle the error using APL, refer to Route Error to APL.
Use Context Cache	Select this option if you need to route HttpRequestCycle udrs to workflows running on different picos. There will be one entry per http request received by the http2 server agent. The cache can be configured with maximum size and maximum time an entry can exist in the cache.
Max Cache Size	Maximum number of http contexts that will be temporally saved on pico that the workflow is running on. A cache entry is removed when the server sends a http response or when a cache timeout has happened for this specific entry.
Max Cache TTL(ms)	Maximum time an entry can be saved in the cache. Important: if the time needed for processing a request is greater than Max Cache TTL - a response may not be sent back.
Timeout
Client Timeout (sec)	The period in seconds after which the HTTP/2 Server should close the connection if a client is inactive. That is, this is the period of inactivity from when the client has opened the connection or received the last expected response until the server should close the connection. For example, if Client Timeout is set to 6, this means that the server will close the connection if the client is inactive for 6 seconds.
Server Timeout (sec)	The period in seconds before which the HTTP/2 Server has to reply to a request. That is, this is the period within which a server has to process a request and send a response to a client. If the time limit is reached, an error response with a status code of 500 will be sent.
Responses
Default Charset	Select the character set you want to use as default character set. UTF-8 is preselected. This character set will be used if the character set requested by Accept-Charset is not found in system.
GZIP Compression Level	If gzip is requested, then the response will be be gzipped with the compression level you specify in this field, 1-9.

Route Error to APL

When enabling Route Error to APL, you will send the request over as part of the RequestCycle UDR where you will then be able to use the Analysis agent to customize your own response. The example shown below has an If statement to catch any requests with errors by checking for isError that are set to True. The APL code will then go on to populate the response and route it back to the HTTP/2 Server agent.

import ultra.openapi.Test_5G.TS29510_Nnrf_NFDiscovery;
consume {

    http.RequestCycle cycleUdr = (http.RequestCycle) input;
    
    debug("input from client \n" + cycleUdr);
    
    ProblemDetails problemDetails = udrCreate(ProblemDetails);
    http.Response response = udrCreate(http.Response);
    
    if (cycleUdr.isError) { // cycleUdr.isError will be true if any errors is encountered while processing the request
	 	list<string> headers = listCreate(string);
        listAdd(headers, "application/problem+json");
        mapSet(response.headers, "Content-Type", headers);
 
        problemDetails.title = "Request Error";
        problemDetails.cause = cycleUdr.errorMessages[0]; // cycleUdr.errorMessages is a list containing error messages set from the error encountered
        problemDetails.status = cycleUdr.errorStatusCode; // cycleUdr.errorStatusCode contains the status code of the error encountered

        response.openAPIUDR = problemDetails;
        response.statusCode = cycleUdr.errorStatusCode;
    } 

    cycleUdr.response = response;
    debug("after apl logic \n" + cycleUdr);

    udrRoute("to_server", cycleUdr);

Overload Protection Tab

HTTP/2 Server Agent Configuration - Overload Protection tab

The Overload Protection tab controls overload protection and contains the following settings:

Setting	Description

Setting	Description
Enable Overload Protection	Select this option if you want to enable overload protection.
Number of Requests	If you have selected enable overload protection, enter the maximum number of requests that are allowed to be sent during the time specified in Average Period (sec). When this number of requests has been reached, further requests will be blocked until the time specified in Wait Duration (sec) has passed, then a retry will be attempted.
Period (sec)	Enter the time in seconds over which the number of requests should be counted.
Wait Before Retry (sec)	Enter the number of seconds to wait before attempting to retry a request.

OpenAPI Tab

The OpenAPI tab contains the following settings:

Setting	Description

Setting	Description
OpenAPI
Use OpenAPI Profile	Select this option if you want the agent to use the OpenAPI profile(s).
OpenAPI Profile	Browse and select the profiles to be used. This field is enabled when the Use OpenAPI Profile option is selected. Click Add to browse for the available OpenAPI profiles. Caution! There are no limits to the number of profiles users can select. However, by selecting a large number of OpenAPI profiles will have significant impact on the overall performance of the workflow.
Enable Validation	Select this option if you want to validate the OpenAPI profile. Warning! Turning this option ON will have a very significant performance impact on the overall performance of the flow. When validation is enabled, each payload will be validated against the Open API schema, an operation that can be very resource-intensive. We recommend only enabling this setting during development and testing and disabling it in a stable production environment. Note! Strict validation is applied against the OpenAPI specification due to the upgrade of third-party libraries. For Example, if the response contains the body but the schema doesn't expect the response to contain the body then it will cause validation failure. Refer to this link for further information https://bitbucket.org/atlassian/swagger-request-validator/issues/246/validator-does-not-check-a-response-body
Override Error Response
Override Error Response on Server Shutdown	Select this option to enable the customization of the HTTP response for when a request to the server is received upon the server being terminated.
Override Error Response on Server Overload	Select this option to enable the customization of the HTTP response for when a request to the server is received upon the server being overloaded.
Status Code	The HTTP error code for the error response. The default error code set is 503 for server shutdown and 429 for server overload.
Content Type	Enter the media type to be used as part of the HTTP header for the response. The default media type is "application/problem+json".
UDR Type	Browse for the UDR that will be populated as part of the HTTP response message.
UDR Field	The fields in the selected UDR Type will be shown in this column.
Type	The data type for the each of the UDR fields will be shown here. supports the following data type: String BigInt Boolean Int
Value	Enter a value that conforms to the data type of the UDR field. The value will then be parsed into the HTTP response when the error is triggered.

5G Tab

The 5G tab contains the following settings:

Setting	Description

Setting	Description
5G
Use 5G Profile	Select this option if you want the agent to use a 5G profile.
5G Profile	Browse and select the profile to be used. This field is enabled when the Use 5G Profile option is selected.
NRF Address Settings
Primary NRF	Enter one or more primary NRF (NF Repository Function) address in this list.
Secondary NRF	Enter one or more secondary NRF (NF Repository Function) address in this list. It is optional to have secondary NRF addresses in any primary NRF address. The secondary NRF addresses serve as alternative connections when the heartbeat with the primary NRF address is not established. This list displays the secondary NRF addresses based on the selected Primary NRF.
Additional Settings
Enable Fall Back (Reconnect to Primary NRF when it is available)	Select this option to have the agent reconnect to the primary NRF address from the secondary address. The agent will send a heartbeat repeatedly to the primary NRF address to determine its availability.
Enable Registration Retry (Retry when NRF addresses failed to register)	Select this option to have the agent retry to register a failed address before connecting to the next address. The agent will attempt to register the failed address based on the configured count and interval before attempting to register the next available address.
Retry Count	Enter the number of retries for failed address. The maximum retry count is 5.
Retry Interval (secs)	Enter the time interval in seconds, between retries. The maximum retry interval is 99 seconds.

Examples

Example 1 - Successful connection to all primary addresses

Address	P1	S1	P2

Address	P1	S1	P2
Availability
Result	Connected		Connected

Example 2 - Connect to secondary address when primary address is unavailable

Address	P1	S1	P2

Address	P1	S1	P2
Availability
Result		Connected	Connected

Example 3 - Connect to all remaining primary addresses when any of the primary and secondary addresses are unavailable

Address	P1	S1	P2

Address	P1	S1	P2
Availability
Result			Connected

Example 4 - All primary and secondary addresses are unavailable upon initiating the workflow

Address	P1	S1	P2

Address	P1	S1	P2
Availability
Result	The workflow is aborted.

Proxy Support

If a proxy server is needed to reach NRF servers please look at HTTP Proxy Support in order to configure the proxy.

Authentication Tab

The Authentication tab contains the following settings:

Setting	Description

Setting	Description
Use Token Authentication	Select this option if you want to use token authentication.
Access Token Required	If you have selected Token Authentication, you can select this option if you want the access token to be required.
Public Key	Paste the public key into this field.