HADOOP-12795. KMS does not log detailed stack trace for unexpected errors. Contributed by Chris Nauroth.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -1695,6 +1695,9 @@ Release 2.8.0 - UNRELEASED
     "hadoop.workaround.non.threadsafe.getpwuid" is different between
     core-default.xml and NativeIO.java (Akira AJISAKA via cmccabe)
 
+    HADOOP-12795. KMS does not log detailed stack trace for unexpected errors.
+    (cnauroth)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -86,12 +86,14 @@ public class KMSExceptionsProvider implements ExceptionMapper<Exception> {
       status = Response.Status.FORBIDDEN;
     } else if (exception instanceof IOException) {
       status = Response.Status.INTERNAL_SERVER_ERROR;
+      log(status, throwable);
     } else if (exception instanceof UnsupportedOperationException) {
       status = Response.Status.BAD_REQUEST;
     } else if (exception instanceof IllegalArgumentException) {
       status = Response.Status.BAD_REQUEST;
     } else {
       status = Response.Status.INTERNAL_SERVER_ERROR;
+      log(status, throwable);
     }
     if (doAudit) {
       KMSWebApp.getKMSAudit().error(KMSMDCFilter.getUgi(),