Github user lamber-ken commented on a diff in the pull request:
https://github.com/apache/flink/pull/6247#discussion_r200431068
--- Diff:
flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/async/AsyncIOExample.java
---
@@ -116,8 +116,8 @@ public void cancel() {
private static class SampleAsyncFunction extends
RichAsyncFunction<Integer, String> {
private static final long serialVersionUID =
2098635244857937717L;
- private static ExecutorService executorService;
- private static Random random;
--- End diff --
SampleAsyncFunction is used as singleton, so synchronize is needed
---
