Early stop on failed start (Alternative to #13087) (#13258)

* Make halt configurable. Don't halt in tests

server/pom.xml

@@ -454,8 +454,9 @@
                     <excludes>
                         <!-- There are UTs for this class but it is very difficult to get required branch coverage -->
                         <exclude>org/apache/druid/metadata/BasicDataSourceExt.class</exclude>
-                        <!-- Tested in the SQL layer, but, oddly, not in this module. -->
+                      <!-- Tested in the SQL layer, but, oddly, not in this module. -->
                         <exclude>org/apache/druid/server/QueryResponse.class</exclude>
+                        <exclude>org/apache/druid/curator/CuratorModule.class</exclude>
                     </excludes>
                 </configuration>
             </plugin>

server/src/main/java/org/apache/druid/curator/CuratorModule.java

@@ -30,6 +30,7 @@ import org.apache.curator.framework.api.ACLProvider;
 import org.apache.curator.framework.imps.DefaultACLProvider;
 import org.apache.curator.retry.BoundedExponentialBackoffRetry;
 import org.apache.curator.shaded.com.google.common.base.Strings;
+import org.apache.druid.concurrent.Threads;
 import org.apache.druid.guice.JsonConfigProvider;
 import org.apache.druid.guice.LazySingleton;
 import org.apache.druid.java.util.common.StringUtils;
@@ -40,6 +41,7 @@ import org.apache.zookeeper.data.ACL;
 
 import java.nio.charset.StandardCharsets;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 public class CuratorModule implements Module
 {
@@ -49,6 +51,23 @@ public class CuratorModule implements Module
   static final int MAX_SLEEP_TIME_MS = 45000;
   private static final int MAX_RETRIES = 29;
 
+  private final boolean haltOnFailedStart;
+
+  public CuratorModule()
+  {
+    this(true);
+  }
+
+  /**
+   *
+   * @param haltOnFailedStart set to true if the JVM needs to be halted within 30 seconds of failed initialization
+   *                          due to unhandled curator exceptions.
+   */
+  public CuratorModule(boolean haltOnFailedStart)
+  {
+    this.haltOnFailedStart = haltOnFailedStart;
+  }
+
   @Override
   public void configure(Binder binder)
   {
@@ -97,6 +116,29 @@ public class CuratorModule implements Module
 
     framework.getUnhandledErrorListenable().addListener((message, e) -> {
       log.error(e, "Unhandled error in Curator, stopping server.");
+
+      if (haltOnFailedStart) {
+        final long startTime = System.currentTimeMillis();
+        final Thread halter = new Thread(
+            () -> {
+              try {
+                Threads.sleepFor(30, TimeUnit.SECONDS);
+              }
+              catch (InterruptedException ignored) {
+
+              }
+              log.warn(
+                  "Could not stop server within %,d millis after unhandled Curator error. Halting immediately.",
+                  System.currentTimeMillis() - startTime
+              );
+              Runtime.getRuntime().halt(1);
+            },
+            "exiter-thread"
+        );
+        halter.setDaemon(true);
+        halter.start();
+      }
+
       shutdown(lifecycle);
     });
 

server/src/test/java/org/apache/druid/curator/CuratorModuleTest.java

@@ -120,7 +120,7 @@ public final class CuratorModuleTest
     return new StartupInjectorBuilder()
         .add(
             new LifecycleModule(),
-            new CuratorModule(),
+            new CuratorModule(false),
             binder -> binder.bind(Properties.class).toInstance(props)
          )
         .build();