From 74971ed8c85400929714a7adff5b61c2ebe9fcee Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 28 Mar 2017 13:30:07 +0100

Subject: [PATCH 17/23] Use virConnectGetAllDomainStats API to collect domain

 stats (RHBZ#1422795).

This is much faster than using the basic libvirt APIs to collect

stats for each domain individually.

Note this will not work unless you have the latest ocaml-libvirt

package which includes this new API binding.

---

 src/collect.ml  | 242 +++++++++++++++++++++++++++++++++++-------------

 src/collect.mli |   1 +

 src/utils.ml    |   6 ++

 src/utils.mli   |   3 +

 4 files changed, 190 insertions(+), 62 deletions(-)

diff --git a/src/collect.ml b/src/collect.ml

index 448ce8c..a1e50a1 100644

--- a/src/collect.ml

+++ b/src/collect.ml

@@ -38,6 +38,7 @@ let parse_device_xml : (int -> [>`R] D.t -> string list * string list) ref =

 type rd_domain = Inactive | Active of rd_active

 and rd_active = {

   rd_domid : int;			(* Domain ID. *)

+  rd_domuuid : Libvirt.uuid;            (* Domain UUID. *)

   rd_dom : [`R] D.t;			(* Domain object. *)

   rd_info : D.info;			(* Domain CPU info now. *)

   rd_block_stats : (string * D.block_stats) list;

@@ -110,6 +111,16 @@ let last_pcpu_usages = Hashtbl.create 13

 let clear_pcpu_display_data () =

   Hashtbl.clear last_pcpu_usages

+(* What to get from virConnectGetAllDomainStats. *)

+let what = [

+  D.StatsState; D.StatsCpuTotal; D.StatsBalloon; D.StatsVcpu;

+  D.StatsInterface; D.StatsBlock

+]

+(* Which domains to get.  Empty list means return all domains:

+ * active, inactive, persistent, transient etc.

+ *)

+let who = []

+

 let collect (conn, _, _, _, _, node_info, _, _) =

   (* Number of physical CPUs (some may be disabled). *)

   let nr_pcpus = C.maxcpus_of_node_info node_info in

@@ -129,72 +140,179 @@ let collect (conn, _, _, _, _, node_info, _, _) =

   (* Get the domains.  Match up with their last_info (if any). *)

   let doms =

-    (* Active domains. *)

-    let n = C.num_of_domains conn in

-    let ids =

-      if n > 0 then Array.to_list (C.list_domains conn n)

-      else [] in

-    let doms =

-      List.filter_map (

-	fun id ->

-	  try

-	    let dom = D.lookup_by_id conn id in

-	    let name = D.get_name dom in

-	    let blkdevs, netifs = get_devices id dom in

+    let doms = D.get_all_domain_stats conn what who in

+    let doms = Array.to_list doms in

+    List.map (

+      fun { D.dom_uuid = uuid; D.params = params } ->

+        let nr_params = Array.length params in

+        let get_param name =

+          let rec loop i =

+            if i = nr_params then None

+            else if fst params.(i) = name then Some (snd params.(i))

+            else loop (i+1)

+          in

+          loop 0

+        in

+        let get_param_int name default =

+          match get_param name with

+          | None -> None

+          | Some (D.TypedFieldInt32 i)

+          | Some (D.TypedFieldUInt32 i) -> Some (Int32.to_int i)

+          | Some (D.TypedFieldInt64 i)

+          | Some (D.TypedFieldUInt64 i) -> Some (Int64.to_int i)

+          | _ -> default

+        in

+        let get_param_int64 name default =

+          match get_param name with

+          | None -> None

+          | Some (D.TypedFieldInt32 i)

+          | Some (D.TypedFieldUInt32 i) -> Some (Int64.of_int32 i)

+          | Some (D.TypedFieldInt64 i)

+          | Some (D.TypedFieldUInt64 i) -> Some i

+          | _ -> default

+        in

-	    (* Get current CPU, block and network stats. *)

-	    let info = D.get_info dom in

-	    let block_stats =

-	      try List.map (fun dev -> dev, D.block_stats dom dev) blkdevs

-	      with

-	      | Libvirt.Not_supported "virDomainBlockStats"

-	      | Libvirt.Virterror _ -> [] in

-	    let interface_stats =

-	      try List.map (fun dev -> dev, D.interface_stats dom dev) netifs

-	      with

-	      | Libvirt.Not_supported "virDomainInterfaceStats"

-	      | Libvirt.Virterror _ -> [] in

+        let dom = D.lookup_by_uuid conn uuid in

+        let id = D.get_id dom in

+        let name = D.get_name dom in

+        let state = get_param_int "state.state" None in

-	    let prev_info, prev_block_stats, prev_interface_stats =

-	      try

-		let prev_info, prev_block_stats, prev_interface_stats =

-		  Hashtbl.find last_info id in

-		Some prev_info, prev_block_stats, prev_interface_stats

-	      with Not_found -> None, [], [] in

+        if state = Some 5 (* VIR_DOMAIN_SHUTOFF *) then

+          (name, Inactive)

+        else (

+          (* Active domain. *)

-	    Some (name,

-                  Active {

-		      rd_domid = id; rd_dom = dom; rd_info = info;

-		      rd_block_stats = block_stats;

-		      rd_interface_stats = interface_stats;

-		      rd_prev_info = prev_info;

-		      rd_prev_block_stats = prev_block_stats;

-		      rd_prev_interface_stats = prev_interface_stats;

-		      rd_cpu_time = 0.; rd_percent_cpu = 0.;

-                      rd_mem_bytes = 0L; rd_mem_percent = 0L;

-		      rd_block_rd_reqs = None; rd_block_wr_reqs = None;

-                      rd_block_rd_bytes = None; rd_block_wr_bytes = None;

-		      rd_net_rx_bytes = None; rd_net_tx_bytes = None;

-		    })

-	  with

-	    Libvirt.Virterror _ -> None (* ignore transient error *)

-      ) ids in

+          (* Synthesize a D.info struct out of the data we have

+           * from virConnectGetAllDomainStats.  Doing this is an

+           * artifact from the old APIs we used to use to fetch

+           * stats, we could simplify here, and also return the

+           * RSS memory. XXX

+           *)

+          let state =

+            match state with

+            | None | Some 0 -> D.InfoNoState

+            | Some 1 -> D.InfoRunning

+            | Some 2 -> D.InfoBlocked

+            | Some 3 -> D.InfoPaused

+            | Some 4 -> D.InfoShutdown

+            | Some 5 -> D.InfoShutoff

+            | Some 6 -> D.InfoCrashed

+            | Some 7 -> D.InfoPaused (* XXX really VIR_DOMAIN_PMSUSPENDED *)

+            | _ -> D.InfoNoState in

+          let memory =

+            match get_param_int64 "balloon.current" None with

+            | None -> 0_L

+            | Some m -> m in

+          let nr_virt_cpu =

+            match get_param_int "vcpu.current" None with

+            | None -> 1

+            | Some v -> v in

+          let cpu_time =

+            (* NB: libvirt does not return cpu.time for non-root domains. *)

+            match get_param_int64 "cpu.time" None with

+            | None -> 0_L

+            | Some ns -> ns in

+          let info = {

+            D.state = state;

+            max_mem = -1_L; (* not used anywhere in virt-top *)

+            memory = memory;

+            nr_virt_cpu = nr_virt_cpu;

+            cpu_time = cpu_time

+          } in

-    (* Inactive domains. *)

-    let doms_inactive =

-      try

-	let n = C.num_of_defined_domains conn in

-	let names =

-	  if n > 0 then Array.to_list (C.list_defined_domains conn n)

-	  else [] in

-	List.map (fun name -> name, Inactive) names

-      with

-      (* Ignore transient errors, in particular errors from

-       * num_of_defined_domains if it cannot contact xend.

-       *)

-      | Libvirt.Virterror _ -> [] in

+          let nr_block_devs =

+            match get_param_int "block.count" None with

+            | None -> 0

+            | Some i -> i in

+          let block_stats =

+            List.map (

+              fun i ->

+              let dev =

+                match get_param (sprintf "block.%d.name" i) with

+                | None -> sprintf "blk%d" i

+                | Some (D.TypedFieldString s) -> s

+                | _ -> assert false in

+              dev, {

+                D.rd_req =

+                  (match get_param_int64 (sprintf "block.%d.rd.reqs" i) None

+                   with None -> 0_L | Some v -> v);

+                rd_bytes =

+                  (match get_param_int64 (sprintf "block.%d.rd.bytes" i) None

+                   with None -> 0_L | Some v -> v);

+                wr_req =

+                  (match get_param_int64 (sprintf "block.%d.wr.reqs" i) None

+                   with None -> 0_L | Some v -> v);

+                wr_bytes =

+                  (match get_param_int64 (sprintf "block.%d.wr.bytes" i) None

+                   with None -> 0_L | Some v -> v);

+                errs = 0_L

+              }

+            ) (range 0 (nr_block_devs-1)) in

-    doms @ doms_inactive in

+          let nr_interface_devs =

+            match get_param_int "net.count" None with

+            | None -> 0

+            | Some i -> i in

+          let interface_stats =

+            List.map (

+              fun i ->

+              let dev =

+                match get_param (sprintf "net.%d.name" i) with

+                | None -> sprintf "net%d" i

+                | Some (D.TypedFieldString s) -> s

+                | _ -> assert false in

+              dev, {

+                D.rx_bytes =

+                  (match get_param_int64 (sprintf "net.%d.rx.bytes" i) None

+                   with None -> 0_L | Some v -> v);

+                rx_packets =

+                  (match get_param_int64 (sprintf "net.%d.rx.pkts" i) None

+                   with None -> 0_L | Some v -> v);

+                rx_errs =

+                  (match get_param_int64 (sprintf "net.%d.rx.errs" i) None

+                   with None -> 0_L | Some v -> v);

+                rx_drop =

+                  (match get_param_int64 (sprintf "net.%d.rx.drop" i) None

+                   with None -> 0_L | Some v -> v);

+                tx_bytes =

+                  (match get_param_int64 (sprintf "net.%d.tx.bytes" i) None

+                   with None -> 0_L | Some v -> v);

+                tx_packets =

+                  (match get_param_int64 (sprintf "net.%d.tx.pkts" i) None

+                   with None -> 0_L | Some v -> v);

+                tx_errs =

+                  (match get_param_int64 (sprintf "net.%d.tx.errs" i) None

+                   with None -> 0_L | Some v -> v);

+                tx_drop =

+                  (match get_param_int64 (sprintf "net.%d.tx.drop" i) None

+                   with None -> 0_L | Some v -> v);

+              }

+            ) (range 0 (nr_interface_devs-1)) in

+

+	  let prev_info, prev_block_stats, prev_interface_stats =

+	    try

+	      let prev_info, prev_block_stats, prev_interface_stats =

+		Hashtbl.find last_info uuid in

+	      Some prev_info, prev_block_stats, prev_interface_stats

+	    with Not_found -> None, [], [] in

+

+	  (name,

+           Active {

+	     rd_domid = id; rd_domuuid = uuid; rd_dom = dom;

+             rd_info = info;

+	     rd_block_stats = block_stats;

+	     rd_interface_stats = interface_stats;

+	     rd_prev_info = prev_info;

+	     rd_prev_block_stats = prev_block_stats;

+	     rd_prev_interface_stats = prev_interface_stats;

+	     rd_cpu_time = 0.; rd_percent_cpu = 0.;

+             rd_mem_bytes = 0L; rd_mem_percent = 0L;

+	     rd_block_rd_reqs = None; rd_block_wr_reqs = None;

+             rd_block_rd_bytes = None; rd_block_wr_bytes = None;

+	     rd_net_rx_bytes = None; rd_net_tx_bytes = None;

+	   })

+        )

+    ) doms in

   (* Calculate the CPU time (ns) and %CPU used by each domain. *)

   let doms =

@@ -329,7 +447,7 @@ let collect (conn, _, _, _, _, node_info, _, _) =

     function

     | (_, Active rd) ->

        let info = rd.rd_info, rd.rd_block_stats, rd.rd_interface_stats in

-       Hashtbl.add last_info rd.rd_domid info

+       Hashtbl.add last_info rd.rd_domuuid info

     | _ -> ()

   ) doms;

diff --git a/src/collect.mli b/src/collect.mli

index 9ad3dcb..3c5492f 100644

--- a/src/collect.mli

+++ b/src/collect.mli

@@ -27,6 +27,7 @@ val parse_device_xml :

 type rd_domain = Inactive | Active of rd_active

 and rd_active = {

   rd_domid : int;			(* Domain ID. *)

+  rd_domuuid : Libvirt.uuid;            (* Domain UUID. *)

   rd_dom : [`R] Libvirt.Domain.t;       (* Domain object. *)

   rd_info : Libvirt.Domain.info;        (* Domain CPU info now. *)

   rd_block_stats : (string * Libvirt.Domain.block_stats) list;

diff --git a/src/utils.ml b/src/utils.ml

index 5fcc905..4332ff7 100644

--- a/src/utils.ml

+++ b/src/utils.ml

@@ -32,6 +32,12 @@ let (/^) = Int64.div

 (* failwithf is a printf-like version of failwith. *)

 let failwithf fs = ksprintf failwith fs

+let rec range a b =

+  if a <= b then

+    a :: range (a+1) b

+  else

+    []

+

 (* Input a whole file as a list of lines. *)

 let input_all_lines chan =

   let lines = ref [] in

diff --git a/src/utils.mli b/src/utils.mli

index 6e81215..3c966f8 100644

--- a/src/utils.mli

+++ b/src/utils.mli

@@ -25,6 +25,9 @@ val (//) : string -> string -> string

 (* failwithf is a printf-like version of failwith. *)

 val failwithf : ('a, unit, string, 'b) format4 -> 'a

+(* Return the list of integers [a..b] (inclusive). *)

+val range : int -> int -> int list

+

 (* Read a configuration file as a list of (lineno, key, value) pairs.

  * If the config file is missing this returns an empty list.

  *)

-- 

2.31.1