CP-13995: Copy and load RRDs from sr-stats vdi during pbd plug

1) Xapi queries xcp-rrdd for RRDs filesystem location.
2) Xapi copies RRDs from sr-stats vdi to filesystem.
3) Xapi asks xcp-rrdd to load these RRDs

Signed-off-by: Sharad Yadav <[email protected]>

Author: sharady

ocaml/xapi/message_forwarding.ml

@@ -3721,12 +3721,7 @@ module Forward = functor(Local: Custom_actions.CUSTOM_ACTIONS) -> struct
 				Helpers.call_api_functions ~__context
 					(fun rpc session_id ->
 						Client.SR.update rpc session_id sr
-					);
-
-				(* Check if SR has SR_STATS capability then create SR-stats VDI *)
-				let sr_record = Db.SR.get_record_internal ~__context ~self:sr in
-				if Smint.(has_capability Sr_stats (Xapi_sr_operations.features_of_sr ~__context sr_record)) then
-					Xapi_vdi_helpers.create_rrd_vdi ~__context ~sr:sr
+					)
 
 		let unplug ~__context ~self =
 			info "PBD.unplug: PBD = '%s'" (pbd_uuid ~__context self);

ocaml/xapi/xapi_pbd.ml

@@ -151,7 +151,15 @@ let plug ~__context ~self =
 				Xapi_sm.register_plugin ~__context query_result;
 
 				(* The allowed-operations depend on the capabilities *)
-				Xapi_sr_operations.update_allowed_operations ~__context ~self:sr
+				Xapi_sr_operations.update_allowed_operations ~__context ~self:sr;
+
+				(* Check if SR has SR_STATS capability and sr master then create SR-stats VDI*)
+				let sr_record = Db.SR.get_record_internal ~__context ~self:sr in
+				if (Smint.(has_capability Sr_stats (Xapi_sr_operations.features_of_sr ~__context sr_record)) &&
+				(Helpers.i_am_srmaster ~__context ~sr)) then begin
+					let vdi = Xapi_vdi_helpers.create_rrd_vdi ~__context ~sr:sr in
+					Xapi_vdi_helpers.push_sr_rdds ~__context ~sr:sr ~vdi:vdi
+				end
 			end
 
 let unplug ~__context ~self =

ocaml/xapi/xapi_vdi_helpers.ml

@@ -265,3 +265,16 @@ let read_rrd ~__context ~sr ~vdi =
 			)
 		)
 
+
+module Rrdd = Rrd_client.Client
+
+let push_sr_rdds ~__context ~sr ~vdi =
+	let sr_uuid = Db.SR.get_uuid ~__context ~self:sr in
+	let sr_rrds_path = Rrdd.sr_rrds_path ~sr_uuid:sr_uuid in
+	let gzipped_rrds = read_rrd ~__context ~sr:sr ~vdi:vdi in
+	begin match gzipped_rrds with
+		| None -> debug "stats vdi doesn't have rdds"
+		| Some x ->
+			Unixext.write_string_to_file sr_rrds_path x;
+			Rrdd.push_sr_rrd ~sr_uuid:sr_uuid
+	end