Log message on slow restarts

core/deployment/src/main/java/io/quarkus/deployment/dev/IsolatedDevModeMain.java

@@ -125,7 +125,7 @@ public void accept(Integer integer) {
                         //we need to set this here, while we still have the correct TCCL
                         //this is so the config is still valid, and we can read HTTP config from application.properties
                         log.info(
-                                "Attempting to start hot replacement endpoint to recover from previous Quarkus startup failure");
+                                "Attempting to start live reload endpoint to recover from previous Quarkus startup failure");
                         if (RuntimeUpdatesProcessor.INSTANCE != null) {
                             Thread.currentThread().setContextClassLoader(curatedApplication.getBaseRuntimeClassLoader());
                             try {

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("Live reload 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) {
@@ -268,7 +280,7 @@ public boolean doScan(boolean userInitiated) throws IOException {
             log.infof("Files changed but restart not needed - notified extensions in: %ss ",
                     Timing.convertToBigDecimalSeconds(System.nanoTime() - startNanoseconds));
         } else if (instrumentationChange) {
-            log.infof("Hot replace performed via instrumentation, no restart needed, total time: %ss ",
+            log.infof("Live reload performed via instrumentation, no restart needed, total time: %ss ",
                     Timing.convertToBigDecimalSeconds(System.nanoTime() - startNanoseconds));
         }
         return false;

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/VertxHttpRecorder.java

@@ -178,7 +178,7 @@ public static void startServerAfterFailedStart() {
             //we shut it down in this case, as we have no idea what state it is in
             final Handler<RoutingContext> prevHotReplacementHandler = hotReplacementHandler;
             shutDownDevMode();
-            // reset back to the older hot replacement handler, so that it can be used
+            // reset back to the older live reload handler, so that it can be used
             // to watch any artifacts that need hot deployment to fix the reason which caused
             // the server start to fail
             hotReplacementHandler = prevHotReplacementHandler;

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/devmode/RemoteSyncHandler.java

@@ -233,7 +233,7 @@ public void handle(Buffer buffer) {
         }).exceptionHandler(new Handler<Throwable>() {
             @Override
             public void handle(Throwable error) {
-                log.error("Failed writing hot replacement data", error);
+                log.error("Failed writing live reload data", error);
                 event.response().setStatusCode(500);
                 event.response().end();
             }

extensions/vertx-http/runtime/src/main/java/io/quarkus/vertx/http/runtime/devmode/VertxHttpHotReplacementSetup.java

@@ -61,7 +61,7 @@ public void handle(Promise<Boolean> event) {
                         try {
                             restart = hotReplacementContext.doScan(true);
                         } catch (Exception e) {
-                            event.fail(new IllegalStateException("Unable to perform hot replacement scanning", e));
+                            event.fail(new IllegalStateException("Unable to perform live reload scanning", e));
                             return;
                         }
                     }