fix(registration): do not restart harvester on refresh (#29)

* fix(registration): do not restart harvester on refresh * ignore start request if already started * log template and period on start * fixup! fix(registration): do not restart harvester on refresh
cryostatio · Jan 5, 2023 · 4a350ba · 4a350ba
1 parent 47abc1f
commit 4a350ba
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Showing 3 changed files with 36 additions and 13 deletions.
diff --git a/src/main/java/io/cryostat/agent/Agent.java b/src/main/java/io/cryostat/agent/Agent.java
@@ -99,10 +99,18 @@ public static void main(String[] args) {
             client.registration()
                     .addRegistrationListener(
                             evt -> {
-                                if (evt.state) {
-                                    client.harvester().start();
-                                } else {
-                                    client.harvester().stop();
+                                switch (evt.state) {
+                                    case REGISTERED:
+                                        client.harvester().start();
+                                        break;
+                                    case UNREGISTERED:
+                                        client.harvester().stop();
+                                        break;
+                                    case REFRESHED:
+                                        break;
+                                    default:
+                                        log.error("Unknown registration state: {}", evt.state);
+                                        break;
                                 }
                             });
             client.registration().start();

diff --git a/src/main/java/io/cryostat/agent/Harvester.java b/src/main/java/io/cryostat/agent/Harvester.java
@@ -84,6 +84,9 @@ class Harvester implements FlightRecorderListener {
     }
 
     public void start() {
+        if (running) {
+            return;
+        }
         if (period <= 0) {
             log.info("Harvester disabled, period {} < 0", period);
             return;
@@ -99,7 +102,7 @@ public void start() {
         try {
             FlightRecorder.addListener(this);
             this.flightRecorder = FlightRecorder.getFlightRecorder();
-            log.info("JFR Harvester started");
+            log.info("JFR Harvester started using template {} with period {}ms", template, period);
         } catch (SecurityException | IllegalStateException e) {
             log.error("Harvester could not start", e);
             return;

diff --git a/src/main/java/io/cryostat/agent/Registration.java b/src/main/java/io/cryostat/agent/Registration.java
@@ -110,12 +110,18 @@ void tryRegister() {
                         .handleAsync(
                                 (plugin, t) -> {
                                     if (plugin != null) {
+                                        boolean previouslyRegistered =
+                                                this.pluginInfo.isInitialized();
                                         this.pluginInfo.copyFrom(plugin);
                                         log.info("Registered as {}", this.pluginInfo.getId());
-                                        notify(true);
+                                        notify(
+                                                previouslyRegistered
+                                                        ? RegistrationEvent.State.REFRESHED
+                                                        : RegistrationEvent.State.REGISTERED);
                                         tryUpdate();
                                     } else if (t != null) {
-                                        notify(false);
+                                        this.pluginInfo.clear();
+                                        notify(RegistrationEvent.State.UNREGISTERED);
                                         throw new RegistrationException(t);
                                     }
 
@@ -214,32 +220,38 @@ CompletableFuture<Void> deregister() {
         return cryostat.deregister(pluginInfo)
                 .handleAsync(
                         (n, t) -> {
+                            this.pluginInfo.clear();
+                            notify(RegistrationEvent.State.UNREGISTERED);
                             if (t != null) {
-                                notify(false);
                                 log.warn(
                                         "Failed to deregister as Cryostat discovery plugin [{}]",
                                         this.pluginInfo.getId());
                             } else {
-                                notify(false);
                                 log.info(
                                         "Deregistered from Cryostat discovery plugin [{}]",
                                         this.pluginInfo.getId());
                             }
-                            this.pluginInfo.clear();
                             return null;
                         },
                         executor);
     }
 
-    private void notify(boolean state) {
+    private void notify(RegistrationEvent.State state) {
         RegistrationEvent evt = new RegistrationEvent(state);
         this.listeners.forEach(listener -> listener.accept(evt));
     }
 
     static class RegistrationEvent {
-        boolean state;
 
-        RegistrationEvent(boolean state) {
+        enum State {
+            REGISTERED,
+            UNREGISTERED,
+            REFRESHED,
+        }
+
+        final State state;
+
+        RegistrationEvent(State state) {
             this.state = state;
         }
     }