From a129ded818177c8d5d78d2a1f61b8723f818ffe8 Mon Sep 17 00:00:00 2001
From: Johnny Lim <izeye@naver.com>
Date: Sat, 4 Jan 2020 19:36:17 +0900
Subject: [PATCH 1/2] Fix flaky tests in TomcatMetricsTest due to timing

---
 .../binder/tomcat/TomcatMetricsTest.java      | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/micrometer-core/src/test/java/io/micrometer/core/instrument/binder/tomcat/TomcatMetricsTest.java b/micrometer-core/src/test/java/io/micrometer/core/instrument/binder/tomcat/TomcatMetricsTest.java
index d5eba10b76..56e4c23207 100644
--- a/micrometer-core/src/test/java/io/micrometer/core/instrument/binder/tomcat/TomcatMetricsTest.java
+++ b/micrometer-core/src/test/java/io/micrometer/core/instrument/binder/tomcat/TomcatMetricsTest.java
@@ -59,6 +59,8 @@
  * @author Johnny Lim
  */
 class TomcatMetricsTest {
+    private static final int PROCESSING_TIME_IN_MILLIS = 10;
+
     private SimpleMeterRegistry registry = new SimpleMeterRegistry(SimpleConfig.DEFAULT, new MockClock());
 
     private int port;
@@ -122,6 +124,14 @@ public Context getContext() {
         assertThat(registry.get("tomcat.sessions.alive.max").tags(tags).timeGauge().value()).isGreaterThan(1.0);
     }
 
+    private void sleep() {
+        try {
+            Thread.sleep(PROCESSING_TIME_IN_MILLIS);
+        } catch (InterruptedException ex) {
+            Thread.currentThread().interrupt();
+        }
+    }
+
     @Test
     void mbeansAvailableAfterBinder() throws Exception {
         TomcatMetrics.monitor(registry, null);
@@ -136,7 +146,7 @@ void mbeansAvailableAfterBinder() throws Exception {
             @Override
             protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
                 IOUtils.toString(req.getInputStream());
-
+                sleep();
                 resp.getOutputStream().write("yes".getBytes());
             }
         };
@@ -162,13 +172,14 @@ protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws I
             return null;
         });
     }
+
     @Test
     void mbeansAvailableBeforeBinder() throws Exception {
         HttpServlet servlet = new HttpServlet() {
             @Override
             protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
                 IOUtils.toString(req.getInputStream());
-
+                sleep();
                 resp.getOutputStream().write("yes".getBytes());
             }
         };
@@ -176,6 +187,8 @@ protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws I
         runTomcat(servlet, () -> {
             TomcatMetrics.monitor(registry, null);
 
+            checkMbeansInitialState();
+
             try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
                 HttpPost post = new HttpPost("http://localhost:" + this.port + "/");
                 post.setEntity(new StringEntity("you there?"));
@@ -236,8 +249,8 @@ private void checkMbeansAfterRequests(long expectedSentBytes) {
         assertThat(registry.get("tomcat.global.received").functionCounter().count()).isEqualTo(10.0);
         assertThat(registry.get("tomcat.global.error").functionCounter().count()).isEqualTo(1.0);
         assertThat(registry.get("tomcat.global.request").functionTimer().count()).isEqualTo(2.0);
-        assertThat(registry.get("tomcat.global.request").functionTimer().totalTime(TimeUnit.MILLISECONDS)).isGreaterThan(0.0);
-        assertThat(registry.get("tomcat.global.request.max").timeGauge().value(TimeUnit.MILLISECONDS)).isGreaterThan(0.0);
+        assertThat(registry.get("tomcat.global.request").functionTimer().totalTime(TimeUnit.MILLISECONDS)).isGreaterThanOrEqualTo(PROCESSING_TIME_IN_MILLIS);
+        assertThat(registry.get("tomcat.global.request.max").timeGauge().value(TimeUnit.MILLISECONDS)).isGreaterThanOrEqualTo(PROCESSING_TIME_IN_MILLIS);
         assertThat(registry.get("tomcat.threads.config.max").gauge().value()).isGreaterThan(0.0);
         assertThat(registry.get("tomcat.threads.busy").gauge().value()).isGreaterThanOrEqualTo(0.0);
         assertThat(registry.get("tomcat.threads.current").gauge().value()).isGreaterThan(0.0);

From c8c6a274db48fe2f994d1bd78cfe4bc5db94d206 Mon Sep 17 00:00:00 2001
From: Johnny Lim <izeye@naver.com>
Date: Sun, 5 Jan 2020 15:40:30 +0900
Subject: [PATCH 2/2] Fix flaky tests in TomcatMetricsTest due to timing
 (#1777)