HTTP Poll

An HTTP Poll task sends HTTP requests to a specified endpoint at regular intervals and continues until a given termination condition is met. This is useful when you need to check the status or output of an HTTP service repeatedly.

Task parameters

Configure these parameters for the HTTP Poll task.

Parameter	Description	Required/ Optional
inputParameters.http_request. uri	The URI for the service. It can be a partial value when using `vipAddress` or it can be the server address.	Required.
inputParameters.http_request. method	The HTTP method. Supported methods: GET HEAD POST PUT PATCH DELETE OPTIONS TRACE	Required.
inputParameters.http_request. accept	The accept header required by the server. The default value is `application/json`. Supported types: application/java-archive application/EDI-X12 application/EDIFACT application/javascript application/octet-stream application/ogg application/pdf application/xhtml+xml application/x-shockwave-flash application/json application/ld+json application/xml application/zip application/x-www-form-urlencoded audio/mpeg audio/x-ms-wma audio/vnd.rn-realaudio audio/x-wav image/gif image/jpeg image/png image/tiff image/vnd.microsoft.icon image/x-icon image/vnd.djvu image/svg+xml Any other headers can be passed as a dynamic variable.	Optional.
inputParameters.http_request. contentType	The content type for the server. The default value is `application/json`. Supported types: application/java-archive application/EDI-X12 application/EDIFACT application/javascript application/octet-stream application/ogg application/pdf application/xhtml+xml application/x-shockwave-flash application/json application/ld+json application/xml application/zip application/x-www-form-urlencoded audio/mpeg audio/x-ms-wma audio/vnd.rn-realaudio audio/x-wav image/gif image/jpeg image/png image/tiff image/vnd.microsoft.icon image/x-icon image/vnd.djvu image/svg+xml It can be passed as a dynamic variable.	Optional.
inputParameters.http_request. terminationCondition	The condition to be evaluated after every HTTP invocation. If the condition is evaluated as `true`, the task is marked as completed. If the condition evaluates to `false`, Conductor schedules the next poll according to the configurations (`pollingInterval` and `pollingStrategy`). When writing the termination condition, it can be passed as a dynamic variable. To use the current HTTP poll as input to the condition, prefix it with a `$`. For example, `$.output.status`. Similarly, refer to previous tasks' output using `$.task_ref_name.output`. Example Termination Condition-`(function(){ return $.output.response.body.randomInt > 10;})();`	Required.
inputParameters.http_request. pollingInterval	The duration in seconds between each HTTP invocation. The default value is 60. The minimum value must be 60 for pollInterval.	Required.
inputParameters.http_request. pollingStrategy	The polling strategy. Supported values: `FIXED`—The duration between each HTTP invocation remains constant. `LINEAR_BACKOFF`— The duration between invocations increases linearly, calculated by multiplying the poll count with the pollingInterval. Note that the poll count increments with each invocation. `EXPONENTIAL_BACKOFF`—The duration between invocations increases exponentially, calculated by multiplying the poll count by 2 base exponential powers of the `pollingInterval`. By default, the polling strategy is set to FIXED.	Required.
inputParameters.http_request. headers	A map of additional HTTP headers to be sent along with the request. Supported types: Accept-Language Authorization Cache Control Content-MD5 From If-Match If-Modified-Since If-None-Match Max-Forwards Pragma If-Range If-Unmodified-Since Proxy-Authorization Range Warning x-api-key Accept-Charset Accept-Encoding Accept-Control-Request-Headers Accept-Control-Request-Method Content-Transfer-Encoding Expect Transfer-Encoding Trailer	Optional.
inputParameters.http_request. body	The request body for POST, PUT, or PATCH methods. Can be text or parameters such as string, number, boolean, null, or object/array.	Required for POST, PUT, or PATCH.
inputParameters.http_request. encode	Determines whether the URI needs encoding. When set to `true`, the Conductor will automatically encode the query parameters before sending the HTTP request. Set this to `false` if the URI is already encoded. The default value is `true`.	Optional.
inputParameters.http_request. acceptedStatusCodes Available since: v5.2.97 and later.	List of HTTP status codes or families to treat as successful. Supports exact codes (such as "404", "302") and family wildcards ("1xx", "2xx", "3xx", "4xx", "5xx"). When not set, only 2xx responses are treated as successful. When explicitly set, only the listed codes are accepted, i.e.; "2xx" is not implicitly included.	Optional.

The following are generic configuration parameters that can be applied to the task and are not specific to the HTTP Poll task.

Caching parameters

You can cache the task outputs using the following parameters. Refer to Caching Task Outputs for a full guide.

Parameter	Description	Required/ Optional
cacheConfig.ttlInSecond	The time to live in seconds, which is the duration for the output to be cached.	Required if using cacheConfig.
cacheConfig.key	The cache key is a unique identifier for the cached output and must be constructed exclusively from the task’s input parameters. It can be a string concatenation that contains the task’s input keys, such as `${uri}-${method}` or `re_${uri}_${method}`.	Required if using cacheConfig.

Other generic parameters

Here are other parameters for configuring the task behavior.

Parameter	Description	Required/ Optional
optional	Whether the task is optional. If set to`true`, any task failure is ignored, and the workflow continues with the task status updated to `COMPLETED_WITH_ERRORS`. However, the task must reach a terminal state. If the task remains incomplete, the workflow waits until it reaches a terminal state before proceeding.	Optional.

Task configuration

This is the task configuration for an HTTP Poll task.

{
     "name": "http_poll",
     "taskReferenceName": "http_poll_ref",
     "type": "HTTP_POLL",
     "inputParameters": {
       "http_request": {
         "uri": "https://orkes-api-tester.orkesconductor.com/api",
         "method": "GET",
         "accept": "application/json",
         "contentType": "application/json",
         "terminationCondition": "(function(){ return $.output.response.body.randomInt > 10;})();",
         "pollingInterval": 60,
         "pollingStrategy": "FIXED",
         "encode": true,
         "headers": {
           "header-1": "${workflow.input.header-1}"
         }
       }
     }
}

Task output

The HTTP Poll task will return the following parameters.

Parameter	Description
response	A JSON object representing the response, if present.
headers	An object containing the metadata about the response.
statusCode	The HTTP status code indicating success or failure of the request.
reasonPhrase	The reason phrase associated with the HTTP status code.
body	The response body containing the data returned by the API.

Examples

Here are some examples for using the HTTP Poll task.

Using HTTP Poll task in a workflow

To demonstrate the HTTP Poll task, consider the following sample workflow.

{
  "name": "your_workflow_name",
  "description": "Sample workflow to get started with HTTP POLL task.",
  "tasks": [
    {
      "name": "example",
      "taskReferenceName": "example",
      "inputParameters": {
        "http_request": {
          "uri": "https://jsonplaceholder.typicode.com/posts/1",
          "method": "GET",
          "terminationCondition": "$.output.body.length > 10 ? true : false;",
          "pollingInterval": "60",
          "pollingStrategy": "FIXED"
        }
      },
      "type": "HTTP_POLL"
    }
  ]
}

In this configuration, the polling conditions are configured as follows:

uri - Specifies the endpoint to be called (https://jsonplaceholder.typicode.com/posts/1 in this example).
method - Defines the HTTP method used for the request (GET in this case).
terminationCondition - Evaluate whether the length of the response body ($.output.body.length) exceeds ten characters to determine task completion.
pollingInterval - Sets the interval (60 seconds) between successive API invocations.
pollingStrategy - Utilizes a FIXED strategy to maintain a constant interval between invocations.

Conductor will execute the HTTP API call every 60 seconds until the condition (response body length > 10) evaluates to true.

Orchestrating long-running APIs

Explore the full tutorial on orchestrating long-running APIs.

HTTP Poll

Task parameters

Task configuration

Task output

Examples

Related pages