CA-389319: Wait and retry for GET_UPDATES_IN_PROGRESS

The query on HTTP endpoint /updates will return the available updates in
JSON format. Prior to the changes in this commit, if a query arrives
when another query is being handled, a "GET_UPDATES_IN_PROGRESS" error
will be returned immediately. This behaviour is not friendly to GUI
client XenCenter.

In this commit, the behaviour is changed to wait and retry in handling
the query in xapi since the "*_IN_PROGGRESS" error is a transient
failure. Tolerating it in xapi (server) side avoids error handling in
client side.

With the change, the "GET_UPDATES_IN_PROGRESS" will not be an error
exposed to users any more. Therefore it is removed.

Signed-off-by: Ming Lu <ming.lu@cloud.com>

Author: minglumlu

ocaml/idl/datamodel_errors.ml

@@ -1913,11 +1913,6 @@ let _ =
     ~doc:"Failed to get available updates from a host." () ;
   error Api_errors.get_updates_failed []
     ~doc:"Failed to get available updates from the pool." () ;
-  error Api_errors.get_updates_in_progress []
-    ~doc:
-      "The operation could not be performed because getting updates is in \
-       progress."
-    () ;
   error Api_errors.apply_updates_in_progress []
     ~doc:
       "The operation could not be performed because applying updates is in \

ocaml/xapi-consts/api_errors.ml

@@ -1261,8 +1261,6 @@ let invalid_repomd_xml = "INVALID_REPOMD_XML"
 
 let get_updates_failed = "GET_UPDATES_FAILED"
 
-let get_updates_in_progress = "GET_UPDATES_IN_PROGRESS"
-
 let apply_updates_in_progress = "APPLY_UPDATES_IN_PROGRESS"
 
 let apply_updates_failed = "APPLY_UPDATES_FAILED"

ocaml/xapi/xapi_pool_helpers.ml

@@ -36,7 +36,6 @@ let blocking_ops =
   ; (`tls_verification_enable, Api_errors.tls_verification_enable_in_progress)
   ; (`configure_repositories, Api_errors.configure_repositories_in_progress)
   ; (`sync_updates, Api_errors.sync_updates_in_progress)
-  ; (`get_updates, Api_errors.get_updates_in_progress)
   ; (`apply_updates, Api_errors.apply_updates_in_progress)
   ]
 
@@ -52,6 +51,7 @@ let wait_ops =
   ; `exchange_ca_certificates_on_join
   ; `copy_primary_host_certs
   ; `eject
+  ; `get_updates
   ]
 
 let all_operations = blocking_ops |> List.map fst |> List.append wait_ops