YARN-5460. Change container runtime type logging in DelegatingLinuxContainerRuntime to debug. Contributed by Shane Kumpf.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/DelegatingLinuxContainerRuntime.java

@@ -63,8 +63,8 @@ public class DelegatingLinuxContainerRuntime implements LinuxContainerRuntime {
       runtime = defaultLinuxContainerRuntime;
     }
 
-    if (LOG.isInfoEnabled()) {
-      LOG.info("Using container runtime: " + runtime.getClass()
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Using container runtime: " + runtime.getClass()
           .getSimpleName());
     }