Merge pull request #5637 from BengangY/private/bengangy/CP-48570

CP-48570: Load recommendations from config file when Xapi starts

ocaml/idl/datamodel_pool.ml

@@ -1490,6 +1490,11 @@ let t =
         ; field ~qualifier:DynamicRO ~lifecycle:[] ~ty:Bool
             ~default_value:(Some (VBool false)) "update_sync_enabled"
             "Whether periodic update synchronization is enabled or not"
+        ; field ~qualifier:DynamicRO ~lifecycle:[]
+            ~ty:(Map (String, String))
+            ~default_value:(Some (VMap [])) "recommendations"
+            "The recommended pool properties for clients to respect for \
+             optimal performance. e.g. max-vm-group=5"
         ]
       )
     ()

ocaml/idl/schematest.ml

@@ -3,7 +3,7 @@ let hash x = Digest.string x |> Digest.to_hex
 (* BEWARE: if this changes, check that schema has been bumped accordingly in
    ocaml/idl/datamodel_common.ml, usually schema_minor_vsn *)
 
-let last_known_schema_hash = "81ba6b9699b3f6c2969dd5510cbbe4aa"
+let last_known_schema_hash = "024b6ce32246d7549898310675631d51"
 
 let current_schema_hash : string =
   let open Datamodel_types in

ocaml/tests/common/test_common.ml

@@ -298,7 +298,8 @@ let make_pool ~__context ~master ?(name_label = "") ?(name_description = "")
     ?(telemetry_uuid = Ref.null) ?(telemetry_frequency = `weekly)
     ?(telemetry_next_collection = API.Date.never)
     ?(last_update_sync = API.Date.epoch) ?(update_sync_frequency = `daily)
-    ?(update_sync_day = 0L) ?(update_sync_enabled = false) () =
+    ?(update_sync_day = 0L) ?(update_sync_enabled = false)
+    ?(recommendations = []) () =
   let pool_ref = Ref.make () in
   Db.Pool.create ~__context ~ref:pool_ref ~uuid:(make_uuid ()) ~name_label
     ~name_description ~master ~default_SR ~suspend_image_SR ~crash_dump_SR
@@ -316,7 +317,7 @@ let make_pool ~__context ~master ?(name_label = "") ?(name_description = "")
     ~migration_compression ~coordinator_bias ~telemetry_uuid
     ~telemetry_frequency ~telemetry_next_collection ~last_update_sync
     ~local_auth_max_threads:8L ~ext_auth_max_threads:8L ~update_sync_frequency
-    ~update_sync_day ~update_sync_enabled ;
+    ~update_sync_day ~update_sync_enabled ~recommendations ;
   pool_ref
 
 let default_sm_features =

ocaml/xapi-cli-server/records.ml

@@ -1493,6 +1493,12 @@ let pool_record rpc session_id pool =
       ; make_field ~name:"update-sync-enabled"
           ~get:(fun () -> (x ()).API.pool_update_sync_enabled |> string_of_bool)
           ()
+      ; make_field ~name:"recommendations"
+          ~get:(fun () ->
+            Record_util.s2sm_to_string "; " (x ()).API.pool_recommendations
+          )
+          ~get_map:(fun () -> (x ()).API.pool_recommendations)
+          ()
       ]
   }
 

ocaml/xapi/dbsync_master.ml

@@ -19,6 +19,7 @@ module D = Debug.Make (struct let name = "dbsync" end)
 
 open D
 open Client
+open Recommendations
 
 (* Synchronising code which is specific to the master *)
 
@@ -53,7 +54,7 @@ let create_pool_record ~__context =
       ~last_update_sync:Xapi_stdext_date.Date.epoch
       ~update_sync_frequency:`weekly ~update_sync_day:0L
       ~update_sync_enabled:false ~local_auth_max_threads:8L
-      ~ext_auth_max_threads:1L
+      ~ext_auth_max_threads:1L ~recommendations:[]
 
 let set_master_ip ~__context =
   let ip =
@@ -336,6 +337,18 @@ let setup_telemetry ~__context =
       )
       ()
 
+let update_pool_recommendations_noexn ~__context =
+  Helpers.log_exn_continue "update pool recommendations"
+    (fun () ->
+      let pool = Helpers.get_pool ~__context in
+      let recommendations =
+        Recommendations.load ~path:!Xapi_globs.pool_recommendations_dir
+        |> StringMap.bindings
+      in
+      Db.Pool.set_recommendations ~__context ~self:pool ~value:recommendations
+    )
+    ()
+
 (* Update the database to reflect current state. Called for both start of day and after
    an agent restart. *)
 let update_env __context =
@@ -360,4 +373,5 @@ let update_env __context =
   Storage_access.on_xapi_start ~__context ;
   if !Xapi_globs.create_tools_sr then
     create_tools_sr_noexn __context ;
-  ensure_vm_metrics_records_exist_noexn __context
+  ensure_vm_metrics_records_exist_noexn __context ;
+  update_pool_recommendations_noexn ~__context

ocaml/xapi/recommendations.ml

@@ -0,0 +1,50 @@
+(*
+ * Copyright (c) Cloud Software Group, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *)
+
+module Unixext = Xapi_stdext_unix.Unixext
+module Config_file = Xcp_service.Config_file
+
+module D = Debug.Make (struct let name = "recommendations" end)
+
+open D
+module StringMap = Map.Make (String)
+
+let process_line map data =
+  match Config_file.parse_line data with
+  | Some (k, v) ->
+      debug "Parsing data, key: %s, value: %s" k v ;
+      StringMap.add k v map
+  | None ->
+      map
+
+let parse map filename =
+  debug "Parsing recommendations file: %s" filename ;
+  Unixext.file_lines_fold process_line map filename
+
+let load ~path =
+  (try Sys.readdir path with _ -> [||])
+  |> Array.to_list
+  |> List.filter (fun f -> Filename.check_suffix f ".conf")
+  |> List.stable_sort compare
+  |> List.map (Filename.concat path)
+  |> List.filter (fun f ->
+         match Unix.((stat f).st_kind) with
+         | Unix.S_REG ->
+             true
+         | _ ->
+             false
+         | exception _ ->
+             false
+     )
+  |> List.fold_left parse StringMap.empty

ocaml/xapi/recommendations.mli

@@ -0,0 +1,17 @@
+(*
+ * Copyright (c) Cloud Software Group, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *)
+
+module StringMap : Map.S with type key = string
+
+val load : path:string -> string StringMap.t

ocaml/xapi/xapi_globs.ml

@@ -1023,6 +1023,8 @@ let python3_path = ref "/usr/bin/python3"
 let observer_experimental_components =
   ref (StringSet.singleton Constants.observer_component_smapi)
 
+let pool_recommendations_dir = ref "/etc/xapi.pool-recommendations.d"
+
 let xapi_globs_spec =
   [
     ( "master_connection_reset_timeout"
@@ -1803,6 +1805,10 @@ module Resources = struct
       , trace_log_dir
       , "Directory for storing traces exported to logs"
       )
+    ; ( "pool-recommendations-dir"
+      , pool_recommendations_dir
+      , "Directory containing files with recommendations in key=value format"
+      )
     ]
 
   let xcp_resources =