Github user zentol commented on a diff in the pull request:
https://github.com/apache/flink/pull/5125#discussion_r155327970
--- Diff:
flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/TwoInputStreamTask.java
---
@@ -80,7 +91,10 @@ public void init() throws Exception {
this.headOperator);
// make sure that stream tasks report their I/O statistics
-
inputProcessor.setMetricGroup(getEnvironment().getMetricGroup().getIOMetricGroup());
+
inputProcessor.setupMetrics(getEnvironment().getMetricGroup().getIOMetricGroup(),
input1WatermarkGauge, input2WatermarkGauge);
+
+
headOperator.getMetricGroup().gauge(MetricNames.IO_CURRENT_INPUT_1_WATERMARK,
input1WatermarkGauge);
--- End diff --
yup. sources don't have input watermark metrics, sinks don't have output
watermarks.
Assigners would work just like any other operator. Assigners overriding the
input watermark will lead to odd observations: having a source (that emits
watermarks) followed by a watermark assigner may result in different
output/input watermarks although they _should_ be identical (source emits 2L,
but assigner "receives" 4L).
To _me_ this seems more intuitive, and it's definitely less complex :/
---
