HDFS-13690. Improve error message when creating encryption zone while KMS is unreachable. Contributed by Kitti Nanasi.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/KMSClientProvider.java

@@ -56,6 +56,7 @@ import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.lang.reflect.UndeclaredThrowableException;
+import java.net.ConnectException;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.MalformedURLException;
@@ -478,10 +479,14 @@ public class KMSClientProvider extends KeyProvider implements CryptoExtension,
           return authUrl.openConnection(url, authToken, doAsUser);
         }
       });
+    } catch (ConnectException ex) {
+      String msg = "Failed to connect to: " + url.toString();
+      LOG.warn(msg);
+      throw new IOException(msg, ex);
+    } catch (SocketTimeoutException ex) {
+      LOG.warn("Failed to connect to {}:{}", url.getHost(), url.getPort());
+      throw ex;
     } catch (IOException ex) {
-      if (ex instanceof SocketTimeoutException) {
-        LOG.warn("Failed to connect to {}:{}", url.getHost(), url.getPort());
-      }
       throw ex;
     } catch (UndeclaredThrowableException ex) {
       throw new IOException(ex.getUndeclaredThrowable());