HADOOP-16500 S3ADelegationTokens to only log at debug on startup (#1269). Contributed by Steve Loughran.

Change-Id: Ifafc15f32791911976d7ebc36fb6e8853f59ed41

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/auth/delegation/S3ADelegationTokens.java

@@ -182,7 +182,7 @@ public class S3ADelegationTokens extends AbstractDTService {
     tokenBinding.bindToFileSystem(getCanonicalUri(), getFileSystem());
     tokenBinding.init(conf);
     tokenBindingName = tokenBinding.getKind().toString();
-    LOG.info("Filesystem {} is using delegation tokens of kind {}",
+    LOG.debug("Filesystem {} is using delegation tokens of kind {}",
         getCanonicalUri(), tokenBindingName);
   }
 
@@ -197,7 +197,7 @@ public class S3ADelegationTokens extends AbstractDTService {
     super.serviceStart();
     tokenBinding.start();
     bindToAnyDelegationToken();
-    LOG.info("S3A Delegation support token {} with {}",
+    LOG.debug("S3A Delegation support token {} with {}",
         identifierToString(),
         tokenBinding.getDescription());
   }
@@ -241,7 +241,7 @@ public class S3ADelegationTokens extends AbstractDTService {
     requireServiceStarted();
     checkState(!isBoundToDT(),
         "Already Bound to a delegation token");
-    LOG.info("No delegation tokens present: using direct authentication");
+    LOG.debug("No delegation tokens present: using direct authentication");
     credentialProviders = Optional.of(tokenBinding.deployUnbonded());
   }
 

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/auth/delegation/SessionTokenBinding.java

@@ -297,7 +297,7 @@ public class SessionTokenBinding extends AbstractDelegationTokenBinding {
     hasSessionCreds = parentCredentials instanceof AWSSessionCredentials;
 
     if (!hasSessionCreds) {
-      LOG.info("Creating STS client for {}", getDescription());
+      LOG.debug("Creating STS client for {}", getDescription());
 
       invoker = new Invoker(new S3ARetryPolicy(conf), LOG_EVENT);
       ClientConfiguration awsConf =