Github user agresch commented on a diff in the pull request:
https://github.com/apache/storm/pull/2534#discussion_r163953643
--- Diff:
storm-server/src/main/java/org/apache/storm/daemon/supervisor/OnlyLatestExecutor.java
---
@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.storm.daemon.supervisor;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Executor;
+
+/**
+ * This allows you to submit a Runnable with a key. If the previous
submission for that key has not yet run,
+ * it will be replaced with the latest one.
+ */
+public class OnlyLatestExecutor<K> {
+ private final Executor exec;
+ private final ConcurrentMap<K, Runnable> latest;
+
+ public OnlyLatestExecutor(Executor exec) {
+ this.exec = exec;
+ latest = new ConcurrentHashMap<>();
+ }
+
+ /**
+ * Run something in the future, but replace it with the latest if it
is taking too long
+ * @param key what to use to dedupe things.
+ * @param r what you want to run.
+ */
+ public void execute(final K key, Runnable r) {
+ Runnable old = latest.put(key, r);
+ if (old == null) {
--- End diff --
do we care about knowing that something is dropped? Seems like we would be
ignorant of any issue that requires tuning.
---
