status: add Busy status code, fix #344

Signed-off-by: Roman Khimov <roman@nspcc.ru>

Author: roman-khimov

proto-docs/status.md

@@ -91,6 +91,7 @@ Section of failed statuses independent of the operation.
 | SIGNATURE_VERIFICATION_FAIL | 2 | [**1026**] Signature verification failure. |
 | NODE_UNDER_MAINTENANCE | 3 | [**1027**] Node is under maintenance. |
 | BAD_REQUEST | 4 | [**1028**] Malformed, syntactically or semantically incorrect request, client-side error. |
+| BUSY | 5 | [**1029**] Some node resources are exhausted and request can't be processed. This is likely to be a transient state and request can be retried in future. |
 
 
 

status/types.proto

@@ -111,6 +111,11 @@ enum CommonFail {
   // [**1028**] Malformed, syntactically or semantically incorrect request,
   // client-side error.
   BAD_REQUEST = 4;
+
+  // [**1029**] Some node resources are exhausted and request can't be
+  // processed. This is likely to be a transient state and request can be
+  // retried in future.
+  BUSY = 5;
 }
 
 // Section of statuses for object-related operations.