Log message on slow restarts

quarkusio · Apr 8, 2021 · 5938293 · 5938293
1 parent ecb6be6
commit 5938293
Showing 1 changed file with 13 additions and 1 deletion.
diff --git a/core/deployment/src/main/java/io/quarkus/deployment/dev/RuntimeUpdatesProcessor.java b/core/deployment/src/main/java/io/quarkus/deployment/dev/RuntimeUpdatesProcessor.java
@@ -31,6 +31,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.TimeUnit;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -82,6 +83,8 @@ public class RuntimeUpdatesProcessor implements HotReplacementContext, Closeable
      */
     private volatile boolean firstScanDone = false;
 
+    private static volatile boolean instrumentationLogPrinted = false;
+
     private final Map<Path, Long> sourceFileTimestamps = new ConcurrentHashMap<>();
     private final Map<Path, Long> watchedFileTimestamps = new ConcurrentHashMap<>();
     private final Map<Path, Long> classFileChangeTimeStamps = new ConcurrentHashMap<>();
@@ -255,7 +258,16 @@ public boolean doScan(boolean userInitiated) throws IOException {
                 || (IsolatedDevModeMain.deploymentProblem != null && userInitiated) || configFileRestartNeeded);
         if (restartNeeded) {
             restartCallback.accept(filesChanged, changedClassResults);
-            log.infof("Hot replace total time: %ss ", Timing.convertToBigDecimalSeconds(System.nanoTime() - startNanoseconds));
+            long timeNanoSeconds = System.nanoTime() - startNanoseconds;
+            log.infof("Hot replace total time: %ss ", Timing.convertToBigDecimalSeconds(timeNanoSeconds));
+            if (TimeUnit.SECONDS.convert(timeNanoSeconds, TimeUnit.NANOSECONDS) >= 4 && !instrumentationEnabled()) {
+                if (!instrumentationLogPrinted) {
+                    instrumentationLogPrinted = true;
+                    log.info(
+                            "Live reload took more than 4 seconds, you may want to enable instrumentation based reload (quarkus.live-reload.instrumentation=true). This allows small changes to take effect without restarting Quarkus.");
+                }
+            }
+
             return true;
         } else if (!filesChanged.isEmpty()) {
             for (Consumer<Set<String>> consumer : noRestartChangesConsumers) {