seqdiag {
    Client; tacker-server; tacker-conductor; tacker-database;
    Client -> "tacker-server"
      [label = "POST /vnflcm/v2/vnf_lcm_op_occs/{vnfLcmOpOccId}/fail"];
    "tacker-server" -> "tacker-database"
      [label = "mark operation as failed"];
    "tacker-server" <-- "tacker-database"
    "tacker-server" ->> "tacker-conductor"
      [label = "trigger asynchronous task"];
    "tacker-conductor" ->> "tacker-conductor" [label = "execute notification process"];
    Client <- "tacker-conductor" [label = "POST {callback URI} (FAILED)"];
    Client --> "tacker-conductor" [label = "Response: 204 No Content"];
    Client <-- "tacker-server" [label = "Response 200 OK"];
  }