diff --git a/rsyslog/undefined_field/undefined_field_test.go b/rsyslog/undefined_field/undefined_field_test.go
index ddce316e16..b29ead960e 100644
--- a/rsyslog/undefined_field/undefined_field_test.go
+++ b/rsyslog/undefined_field/undefined_field_test.go
@@ -188,6 +188,7 @@ func TestUndefinedMaxNumFields(t *testing.T) {
 	var val1 float64 = 1111
 	var val2 float64 = 2222
 	undefined2Map := map[string]interface{}{
+		"":  "",
 		"undefined2":  "undefined2",
 		"undefined22": val2,
 		"undefined23": false,
@@ -200,7 +201,10 @@ func TestUndefinedMaxNumFields(t *testing.T) {
 		"undefined.6": "undefined6",
 	}
 	fieldlist = []string{"undefined1", "undefined11", "undefined12", "undefined2", "undefined.6"}
-	if err = checkFieldsEqual(t, undefinedMap, inputMap, fieldlist); err != nil {
+	if err := json.Unmarshal([]byte(undefString), &undefMap); err != nil {
+		t.Errorf("json.Unmarshal failed for undefString [%v]: %v", undefString, err)
+	}
+	if err = checkFieldsEqual(t, undefinedMap, undefMap, fieldlist); err != nil {
 		t.Error(err)
 	}
 }
diff --git a/test/zzz-rsyslog.sh b/test/zzz-rsyslog.sh
index f88c832721..a4bedce510 100755
--- a/test/zzz-rsyslog.sh
+++ b/test/zzz-rsyslog.sh
@@ -10,6 +10,8 @@ os::util::environment::use_sudo
 os::test::junit::declare_suite_start "test/zzz-rsyslog"
 
 pushd ${OS_O_A_L_DIR}/rsyslog/undefined_field > /dev/null
+cp undefined_field.go $ARTIFACT_DIR || :
+cp undefined_field_test.go $ARTIFACT_DIR || :
 go test -v 2>&1 | artifact_out
 popd > /dev/null
 
@@ -46,6 +48,7 @@ cleanup() {
     set +e
     get_all_logging_pod_logs
     oc get cm rsyslog -o yaml > $ARTIFACT_DIR/rsyslog_configmap.yaml 2>&1
+    oc get cm rsyslog-bin -o yaml > $ARTIFACT_DIR/rsyslog.sh 2>&1
     if [ "deploy_using_ansible" = "$deployfunc" ] ; then
         if [ -n "${tmpinv:-}" -a -f "${tmpinv:-}" ] ; then
             rm -f $tmpinv
@@ -61,6 +64,7 @@ cleanup() {
         start_fluentd true 2>&1 | artifact_out
     else
         rpod=$( get_running_pod rsyslog )
+        oc exec $rpod -c rsyslog -- env > $ARTIFACT_DIR/rsyslog_env.txt 2>&1 || :
         oc exec $rpod -c rsyslog -- cat /var/log/rsyslog/rsyslog_debug.log > $ARTIFACT_DIR/rsyslog_debug.log 2>&1 || :
         oc get clusterlogging instance -o yaml > $ARTIFACT_DIR/clinstance.yaml 2>&1
         oc describe deploy cluster-logging-operator > $ARTIFACT_DIR/deploy.clo.yaml 2>&1
@@ -175,6 +179,10 @@ else
 fi
 
 $deployfunc
+# Set kubernetes to CDM_KEEP_EMPTY_FIELDS to keep "openshift_io/node-selector": "" in
+# kubernetes.namespace_annotations.openshift_io/node-selector
+oc set env $rsyslog_ds CDM_KEEP_EMPTY_FIELDS="kubernetes"
+start_rsyslog
 
 sleep 10
 wait_for_fluentd_to_catch_up get_logmessage get_logmessage2
@@ -237,6 +245,10 @@ os::cmd::expect_success_and_not_text "cat $ops | jq -r .hits.hits[0]._source.hos
 ts=$( cat $ops | jq -r '.hits.hits[0]._source."@timestamp"' )
 os::cmd::expect_success "test ${ts} != null"
 
+# Unset CDM_KEEP_EMPTY_FIELDS
+oc set env $rsyslog_ds CDM_KEEP_EMPTY_FIELDS-
+start_rsyslog
+
 # see if the prometheus exporter is working
 rpod="$( get_running_pod rsyslog )"
 rpod_ip="$( oc get pod ${rpod} -o jsonpath='{.status.podIP}' )"
@@ -365,8 +377,9 @@ os::cmd::try_until_success "oc exec $rpod -c rsyslog -- grep 'use_undefined:' /v
 artifact_log "1. default values"
 rpod=$( get_running_pod rsyslog )
 # skipped empty by mmnormalize/parse_json_skip_empty; mmexternal won't be executed.
-oc exec $rpod -c rsyslog -- ls -l /var/lib/rsyslog.pod/undefined.json | artifact_out || :
-oc exec $rpod -c rsyslog -- cat /var/lib/rsyslog.pod/undefined.json | artifact_out || :
+oc exec $rpod -c rsyslog -- env | artifact_out
+oc exec $rpod -c rsyslog -- ls -l /var/lib/rsyslog.pod/undefined.json 2>&1 | artifact_out || :
+oc exec $rpod -c rsyslog -- cat /var/lib/rsyslog.pod/undefined.json 2>&1 | artifact_out || :
 wait_for_fluentd_to_catch_up get_logmessage get_logmessage2
 os::cmd::expect_success "cat $proj | python $OS_O_A_L_DIR/hack/testing/test-viaq-data-model.py test1"
 os::cmd::expect_success "cat $ops | python $OS_O_A_L_DIR/hack/testing/test-viaq-data-model.py test1"