有没有办法只将过滤后的事件从Apache Flink流传递到AsyncDataStream / AsyncIO流？

Question

所以我在Json中有一堆日志，我有一个流来验证/过滤掉所需的Json并且效果很好！

现在我想使用AsyncIO从过滤的Json中进行数据库查找，但似乎asyncInvoke正在流的每个输入上执行而不是过滤结果。

DataStream<String> stringInputStream = env.addSource(flinkKafkaConsumer);

stringInputStream
    .flatMap(stringToJsonObject()) // Make sure only JSON logs go through.
    .returns(JsonObject.class)
    .filter(filterLogs("my-app")) // Filter logs for my-app
    .flatMap(jsonStringToJsonObject("someJsonEncodedStringField"))
    .returns(JsonObject.class)
    .filter(filterSpecificEvent()); // This stream works as expected, putting print() here only prints filtered events.

DataStream<JsonObject> lookupCarrierCodeStream = 
    AsyncDataStream.orderedWait(stringInputStream, lookupCodesInDB(), 3000, TimeUnit.MILLISECONDS, 100);

private static RichAsyncFunction<String, JsonObject> lookupCodesInDB() {
  return new RichAsyncFunction<String, JsonObject>() {
      @Override
      public void asyncInvoke(String input, ResultFuture<JsonObject> resultFuture) throws Exception {
          // This seems to receive all events, rather then the filtered ones.
          System.out.println("Input:" + input);

          resultFuture.complete(Collections.singleton(new JsonObject(input)));
      }
  };
}

更新

如果我像这样拆分流似乎有效...

DataStream<String> kafkaStringInput = env.addSource(flinkKafkaConsumer);

DataStream<JsonObject> jsonLogsInput = ...;
DataStream<JsonObject> appLogsInput = ...;
DataStream<JsonObject> evenInput = ...;

DataStream<JsonObject> lookupStream = AsyncDataStream.orderedWait(evenInput, ...);

不知道为什么它不会流利，但确定。

Answer 1

将函数应用于流，如

eventStream
  .flatmap()

不修改eventStream，而是返回一个新流。

所以你想做这样的事情：

DataStream<JsonObject>filteredStream = stringInputStream
  .flatMap(stringToJsonObject())
  .returns(JsonObject.class)
  .filter(filterLogs("my-app"))
  .flatMap(jsonStringToJsonObject("someJsonEncodedStringField"))
  .returns(JsonObject.class)
  .filter(filterSpecificEvent());

DataStream<JsonObject> lookupCarrierCodeStream = 
  AsyncDataStream.orderedWait(filteredStream, lookupCodesInDB(), 3000, TimeUnit.MILLISECONDS, 100);