QueryStreamHandler¶

QueryStreamHandler is a Handler (Vert.x) to handle HTTP requests to the following REST endpoints:

• /query
• /query-stream

Creating Instance¶

QueryStreamHandler takes the following to be created:

• Endpoints
• ConnectionQueryManager
• Context (Vert.x)
• Server
• queryCompatibilityMode flag

QueryStreamHandler is created when:

• ServerVerticle is requested to setup a Router

Handling HTTP Request¶

void handle(
  RoutingContext routingContext)

handle is part of the Handler (Vert.x) abstraction.

handle requests the Endpoints to createQueryPublisher and then handleQueryPublisher.

handleQueryPublisher¶

void handleQueryPublisher(
  RoutingContext routingContext,
  QueryPublisher queryPublisher,
  MetricsCallbackHolder metricsCallbackHolder,
  long startTimeNanos)

For a pull query, handleQueryPublisher...FIXME

For a scalable push query, handleQueryPublisher...FIXME

Otherwise, handleQueryPublisher...FIXME

In the end, handleQueryPublisher requests the given QueryPublisher to subscribe to a new QuerySubscriber.

Logging¶

Enable ALL logging level for io.confluent.ksql.api.server.QueryStreamHandler logger to see what happens inside.

Add the following line to log4j.properties:

log4j.logger.io.confluent.ksql.api.server.QueryStreamHandler=ALL

Refer to Logging.