HDDS-282. Consolidate logging in scm/container-service. Contributed by Elek Marton.

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/EndpointStateMachine.java

@@ -203,11 +203,11 @@ public class EndpointStateMachine
     this.incMissed();
     if (this.getMissedCount() % getLogWarnInterval(conf) ==
         0) {
-      LOG.warn("Unable to communicate to SCM server at {}. We have not been " +
+      LOG.error("Unable to communicate to SCM server at {}. We have not been " +
               "able to communicate to this SCM server for past {} seconds.",
           this.getAddress().getHostString() + ":" + this.getAddress().getPort(),
           this.getMissedCount() * getScmHeartbeatInterval(
-              this.conf));
+              this.conf), ex);
     }
   }
 

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/states/endpoint/RegisterEndpointTask.java

@@ -125,8 +125,7 @@ public final class RegisterEndpointTask implements
       rpcEndPoint.setState(nextState);
       rpcEndPoint.zeroMissedCount();
     } catch (IOException ex) {
-      rpcEndPoint.logIfNeeded(ex
-      );
+      rpcEndPoint.logIfNeeded(ex);
     } finally {
       rpcEndPoint.unlock();
     }

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/statemachine/background/BlockDeletingService.java

@@ -119,9 +119,11 @@ public class BlockDeletingService extends BackgroundService{
       // configured.
       containers = containerSet.chooseContainerForBlockDeletion(
           containerLimitPerInterval, containerDeletionPolicy);
+      if (containers.size() > 0) {
         LOG.info("Plan to choose {} containers for block deletion, "
                 + "actually returns {} valid containers.",
             containerLimitPerInterval, containers.size());
+      }
 
       for(ContainerData container : containers) {
         BlockDeletingTask containerTask =

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/server/events/EventQueue.java

@@ -155,8 +155,7 @@ public class EventQueue implements EventPublisher, AutoCloseable {
       }
 
     } else {
-      throw new IllegalArgumentException(
-          "No event handler registered for event " + event);
+      LOG.warn("No event handler registered for event " + event);
     }
 
   }

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/server/events/TypedEvent.java

@@ -50,7 +50,9 @@ public class TypedEvent<T> implements Event<T> {
 
   @Override
   public String toString() {
-    return "TypedEvent{" + "payloadType=" + payloadType + ", name='" + name
-        + '\'' + '}';
+    return "TypedEvent{" +
+        "payloadType=" + payloadType.getSimpleName() +
+        ", name='" + name + '\'' +
+        '}';
   }
 }