CA-270642, CA-265691: Copy metrics from snapshot when reverting

Do not copy the metrics reference from the `snapshot_metadata`, because this
comes from the original VM (the one that the snapshot was taken of), and may
have been destroyed meanwhile. The snapshot itself has a copy of the VM_metrics
record of the original VM at the time the snapshot was taken, so copy that
when restoring the VM.

This applies to snapshots as well as checkpoints.

Signed-off-by: Rob Hoes <[email protected]>

Author: robhoes

ocaml/database/db_names.ml

@@ -33,6 +33,7 @@ let is_a_snapshot = "is_a_snapshot"
 let is_control_domain = "is_control_domain"
 let platform = "platform"
 let other_config = "other_config"
+let metrics = "metrics"
 let guest_metrics = "guest_metrics"
 let parent = "parent"
 let snapshot_of = "snapshot_of"

ocaml/xapi/xapi_vm_clone.ml

@@ -232,33 +232,7 @@ let copy_vm_record ?(snapshot_info_record) ~__context ~vm ~disk_op ~new_name ~ne
     then (Xapi_globs.base_template_name_key, all.Db_actions.vM_name_label) :: other_config
     else other_config
   in
-  (* Copy the old metrics if available, otherwise generate a fresh one *)
-  let m =
-    if Db.is_valid_ref __context all.Db_actions.vM_metrics
-    then Some (Db.VM_metrics.get_record_internal ~__context ~self:all.Db_actions.vM_metrics)
-    else None
-  in
-  let metrics = Ref.make ()
-  and metrics_uuid = Uuid.to_string (Uuid.make_uuid ()) in
-  Db.VM_metrics.create ~__context
-    ~ref:metrics
-    ~uuid:metrics_uuid
-    ~memory_actual:(default 0L (may (fun x -> x.Db_actions.vM_metrics_memory_actual) m))
-    ~vCPUs_number:(default 0L (may (fun x -> x.Db_actions.vM_metrics_VCPUs_number) m))
-    ~vCPUs_utilisation:(default [(0L, 0.)] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_utilisation) m))
-    ~vCPUs_CPU:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_CPU) m))
-    ~vCPUs_params:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_params) m))
-    ~vCPUs_flags:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_flags) m))
-    ~start_time:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_start_time) m))
-    ~install_time:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_install_time) m))
-    ~state:(default [] (may (fun x -> x.Db_actions.vM_metrics_state) m))
-    ~last_updated:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_last_updated) m))
-    ~other_config:(default [] (may (fun x -> x.Db_actions.vM_metrics_other_config) m))
-    ~nomigrate:(default false (may (fun x -> x.Db_actions.vM_metrics_nomigrate) m))
-    ~hvm:(default false (may (fun x -> x.Db_actions.vM_metrics_hvm) m))
-    ~nested_virt:(default false (may (fun x -> x.Db_actions.vM_metrics_nested_virt) m))
-  ;
-
+  let metrics = Xapi_vm_helpers.copy_metrics ~__context ~vm in
   let guest_metrics = Xapi_vm_helpers.copy_guest_metrics ~__context ~vm in
 
   (* compute the parent VM *)

ocaml/xapi/xapi_vm_helpers.ml

@@ -22,6 +22,8 @@ open Xapi_vm_memory_constraints
 open Xapi_network_attach_helpers
 open Listext
 open Fun
+open Pervasiveext
+
 module XenAPI = Client.Client
 
 module D=Debug.Make(struct let name="xapi" end)
@@ -852,7 +854,38 @@ let delete_guest_metrics ~__context ~self:vm =
   Db.VM.set_guest_metrics ~__context ~self:vm ~value:Ref.null;
   (try Db.VM_guest_metrics.destroy ~__context ~self:guest_metrics with _ -> ())
 
+let copy_metrics ~__context ~vm =
+  (* Copy the old metrics if available, otherwise generate a fresh one *)
+  let m =
+    let mref = Db.VM.get_metrics ~__context ~self:vm in
+    if Db.is_valid_ref __context mref
+    then Some (Db.VM_metrics.get_record_internal ~__context ~self:mref)
+    else None
+  in
+  let metrics = Ref.make ()
+  and metrics_uuid = Uuid.to_string (Uuid.make_uuid ()) in
+  Db.VM_metrics.create ~__context
+    ~ref:metrics
+    ~uuid:metrics_uuid
+    ~memory_actual:(default 0L (may (fun x -> x.Db_actions.vM_metrics_memory_actual) m))
+    ~vCPUs_number:(default 0L (may (fun x -> x.Db_actions.vM_metrics_VCPUs_number) m))
+    ~vCPUs_utilisation:(default [(0L, 0.)] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_utilisation) m))
+    ~vCPUs_CPU:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_CPU) m))
+    ~vCPUs_params:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_params) m))
+    ~vCPUs_flags:(default [] (may (fun x -> x.Db_actions.vM_metrics_VCPUs_flags) m))
+    ~start_time:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_start_time) m))
+    ~install_time:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_install_time) m))
+    ~state:(default [] (may (fun x -> x.Db_actions.vM_metrics_state) m))
+    ~last_updated:(default Date.never (may (fun x -> x.Db_actions.vM_metrics_last_updated) m))
+    ~other_config:(default [] (may (fun x -> x.Db_actions.vM_metrics_other_config) m))
+    ~nomigrate:(default false (may (fun x -> x.Db_actions.vM_metrics_nomigrate) m))
+    ~hvm:(default false (may (fun x -> x.Db_actions.vM_metrics_hvm) m))
+    ~nested_virt:(default false (may (fun x -> x.Db_actions.vM_metrics_nested_virt) m))
+  ;
+  metrics
+
 let copy_guest_metrics ~__context ~vm =
+  (* Copy the old metrics if available, otherwise return Ref.null *)
   try
     let gm = Db.VM.get_guest_metrics ~__context ~self:vm in
     let all = Db.VM_guest_metrics.get_record ~__context ~self:gm in

ocaml/xapi/xapi_vm_snapshot.ml

@@ -398,6 +398,17 @@ let update_guest_metrics ~__context ~vm ~snapshot =
     Db.VM.set_guest_metrics ~__context ~self:vm ~value:new_gm
   end
 
+let update_metrics ~__context ~vm ~snapshot =
+  let snap_m = Db.VM.get_metrics ~__context ~self:snapshot in
+  let vm_m = Db.VM.get_metrics ~__context ~self:vm in
+
+  debug "Reverting the metrics";
+  if Db.is_valid_ref __context vm_m then Db.VM_metrics.destroy ~__context ~self:vm_m;
+  if Db.is_valid_ref __context snap_m then begin
+    let new_m = Xapi_vm_helpers.copy_metrics ~__context ~vm:snapshot in
+    Db.VM.set_metrics ~__context ~self:vm ~value:new_m
+  end
+
 let update_parent ~__context ~vm ~snapshot =
   Db.VM.set_parent ~__context ~self:vm ~value:snapshot
 
@@ -409,6 +420,7 @@ let do_not_copy = [
   Db_names.parent;
   Db_names.current_operations;
   Db_names.allowed_operations;
+  Db_names.metrics;
   Db_names.guest_metrics;
   Db_names.resident_on;
   Db_names.domid;
@@ -465,6 +477,7 @@ let revert ~__context ~snapshot ~vm =
 
     update_vifs_vbds_vgpus_and_vusbs ~__context ~snapshot ~vm;
     update_guest_metrics ~__context ~snapshot ~vm;
+    update_metrics ~__context ~snapshot ~vm;
     update_parent ~__context ~snapshot ~vm;
     TaskHelper.set_progress ~__context 1.;