Http

The http sink connects and sends http(s) requests to configured downstream HTTP(s) server over single connection per worker thread. If server doesn't close the connection, it will be reused for subsequent requests.

If server is not available, sink will keep on trying to re-connect each time new event arrives. In other words, if there are not events in the pipeline, this sink will not try to connect.

This sink can execute only POST, PUT, PATCH or DELETE requests.

JAVAYAML

.consumeFromSource(...)
.terminateWithSink(HttpSinkConfigBuilder.builder()
    .withHttpClient(value)
    .withRetryConfiguration(builder -> builder
        .withRetries(value)
        .withBackoffDelay(value)
        .withMaxBackoffDelay(value)
    )
    .withExceptionHandler(value)
)

sink:
  http:
    httpClient: value
    retryConfiguration:
      retries: value
      backoffDelay: value
      maxBackoffDelay: value
    exceptionHandler: value

Java dependency management

Add this declaration to your dependency management system to access the configuration DSL for this plugin in Java.

MavenGradle

<dependency>
    <groupId>org.voltdb</groupId>
    <artifactId>volt-stream-plugin-http-api</artifactId>
    <version>1.6.0</version>
</dependency>

implementation group: 'org.voltdb', name: 'volt-stream-plugin-http-api', version: '1.6.0'

Properties

httpClient

Http client reference Required.

Type: object

retryConfiguration

Retry configuration of failed request. Type: object

Fields of retryConfiguration:

retryConfiguration.retries

Number of retry attempts after a request failure. Type: number

Default value: 3

retryConfiguration.backoffDelay

Initial delay before the first retry attempt. Type: object

Default value: PT0.2S

retryConfiguration.maxBackoffDelay

Maximum delay between consecutive retry attempts. Type: object

Default value: PT3S

exceptionHandler

Custom exception handler enabling interception of all errors related to this sink.

Type: object

JSON Schema

You can validate or explore the configuration using its JSON Schema.

Usage Examples

JAVAYAML

 stream
        .withName("Read data from HTTP server and print to stdout")
        .configureResource("a-http-client", HttpClientResourceConfigBuilder.builder()
               .withAddress(HostAndPort.fromParts("localhost", 9090))
               ...
               )
        .consumeFromSource(...)
        .processWith(event -> new HttpRequest(...))
        .terminateWithSink(HttpSinkConfigBuilder.builder()
               .withHttpClientName("a-http-client")
               .withHeaders(Map.of("Content-Type", "application/json"))
        );

There is also a way to configure http client resource inline directly.

 stream
        .withName("Read data from HTTP server and print to stdout")
        .consumeFromSource(...)
        .processWith(event -> new HttpRequest(...))
        .terminateWithSink(HttpSinkConfigBuilder.builder()
               // the name of the resource is `httpClient`
               .withHttpClientBuilder(builder -> {
                     builder.withAddress(HostAndPort.fromParts("localhost", 9090))
               })
               .withHeaders(Map.of("Content-Type", "application/json"))
        );

resources:
- name: a-http-client
  http-client:
    address: localhost:32112
    ...
source:
  ...
sink:
  http:
    httpClientReference: a-http-client
    headers:
      Content-Type: application/json

the http-client resource can be configured inline like

source:
  ...
sink:
  http:
    httpClient:
      address: localhost:32112
      ...
    headers:
      Content-Type: application/json