Update log level for better problem addressing (apache#17884)

Author: FrankChen021

processing/src/main/java/org/apache/druid/java/util/common/lifecycle/Lifecycle.java

@@ -442,7 +442,7 @@ public void start() throws Exception
           }
         }
         if (doStart) {
-          log.debug("Invoking start method[%s] on object[%s].", method, o);
+          log.info("Starting lifecycle [%s#%s]", o.getClass().getSimpleName(), method.getName());
           method.invoke(o);
         }
       }
@@ -460,7 +460,7 @@ public void stop()
           }
         }
         if (doStop) {
-          log.debug("Invoking stop method[%s] on object[%s].", method, o);
+          log.debug("Stopping lifecyle [%s#%s].", o.getClass().getSimpleName(), method.getName());
           try {
             method.invoke(o);
           }

server/src/main/java/org/apache/druid/discovery/BaseNodeRoleWatcher.java

@@ -187,7 +187,7 @@ public void childRemoved(DiscoveryDruidNode druidNode)
         return;
       }
 
-      LOGGER.info("Node [%s] of role [%s] went offline.", druidNode.getDruidNode().getUriToUse(), nodeRole.getJsonName());
+      LOGGER.warn("Node [%s] of role [%s] went offline.", druidNode.getDruidNode().getUriToUse(), nodeRole.getJsonName());
 
       removeNode(druidNode);
     }