# HG changeset patch
# User Jon Ludlam <Jonathan.Ludlam@xxxxxxxxxxxxx>
# Date 1285345651 -3600
# Node ID c9096a7ecb48a10462c280b8b672e8bf04bbd3e1
# Parent 243ef81d48f72655dc409b127eb39785e4a5f5c0
Add RRDs to measure the use of the local disk cache.
Signed-off-by: Jon Ludlam <Jonathan.Ludlam@xxxxxxxxxxxxx>
diff -r 243ef81d48f7 -r c9096a7ecb48 ocaml/xapi/dbsync_slave.ml
--- a/ocaml/xapi/dbsync_slave.ml
+++ b/ocaml/xapi/dbsync_slave.ml
@@ -480,6 +480,15 @@
(* record who we are in xapi_globs *)
Xapi_globs.localhost_ref := Helpers.get_localhost ~__context;
+ (* Set the cache_sr *)
+ begin
+ try
+ let cache_sr = Db.Host.get_local_cache_sr ~__context
~self:(Helpers.get_localhost ~__context) in
+ let cache_sr_uuid = Db.SR.get_uuid ~__context ~self:cache_sr
in
+ Monitor.set_cache_sr cache_sr_uuid
+ with _ -> Monitor.unset_cache_sr ()
+ end;
+
(* Load the host rrd *)
Monitor_rrds.load_rrd ~__context (Helpers.get_localhost_uuid ()) true;
diff -r 243ef81d48f7 -r c9096a7ecb48 ocaml/xapi/monitor.ml
--- a/ocaml/xapi/monitor.ml
+++ b/ocaml/xapi/monitor.ml
@@ -422,6 +422,77 @@
(Host,ds_make ~name:"xapi_allocation_kib" ~description:"Memory allocation
done by the xapi daemon"
~value:(Rrd.VT_Float xapigrad_kib) ~ty:Rrd.Derive ~min:0.0 ~default:true
());
]
+
+(**** Local cache SR stuff *)
+
+type last_vals = {
+ time : float;
+ cache_size_raw : int64;
+ cache_hits_raw : int64;
+ cache_misses_raw : int64;
+}
+
+let last_cache_stats = ref None
+let cache_sr_uuid = ref None
+let cache_sr_lock = Mutex.create ()
+let cached_cache_dss = ref []
+
+(* Avoid a db lookup every 5 secs by caching the cache sr uuid. Set by
xapi_host and dbsync_slave *)
+let set_cache_sr sr_uuid =
+ Mutex.execute cache_sr_lock (fun () -> cache_sr_uuid := Some sr_uuid)
+
+let unset_cache_sr () =
+ Mutex.execute cache_sr_lock (fun () -> cache_sr_uuid := None)
+
+let read_cache_stats timestamp =
+ let cache_sr_opt = Mutex.execute cache_sr_lock (fun () ->
!cache_sr_uuid) in
+
+ let do_read cache_sr =
+ let (cache_stats_out,err) =
Forkhelpers.execute_command_get_output "/opt/xensource/bin/tapdisk-cache-stats"
[cache_sr] in
+ let assoc_list =
+ List.filter_map (fun line -> try let hd::tl =
String.split '=' line in Some (hd,String.concat "=" tl) with _ -> None)
+ (String.split '\n' cache_stats_out)
+ in
+ (*debug "assoc_list: [%s]" (String.concat ";" (List.map (fun
(a,b) -> Printf.sprintf "%s=%s" a b) assoc_list));*)
+ { time = timestamp;
+ cache_size_raw = Int64.of_string (List.assoc
"TOTAL_CACHE_UTILISATION" assoc_list);
+ cache_hits_raw = Int64.of_string (List.assoc
"TOTAL_CACHE_HITS" assoc_list);
+ cache_misses_raw = Int64.of_string (List.assoc
"TOTAL_CACHE_MISSES" assoc_list); }
+ in
+
+ let get_dss cache_sr oldvals newvals =
+ [
+ (Host,ds_make ~name:(Printf.sprintf "sr_%s_cache_size"
cache_sr) ~description:"Size in bytes of the cache SR"
+ ~value:(Rrd.VT_Int64 newvals.cache_size_raw)
~ty:Rrd.Gauge ~min:0.0 ~default:true ());
+ (Host,ds_make ~name:(Printf.sprintf "sr_%s_cache_hits"
cache_sr) ~description:"Hits per second of the cache"
+ ~value:(Rrd.VT_Int64 (Int64.div (Int64.sub
newvals.cache_hits_raw oldvals.cache_hits_raw)
+ (Int64.of_float (newvals.time -.
oldvals.time))))
+ ~ty:Rrd.Gauge ~min:0.0 ~default:true ());
+ (Host,ds_make ~name:(Printf.sprintf
"sr_%s_cache_misses" cache_sr) ~description:"Misses per second of the cache"
+ ~value:(Rrd.VT_Int64 (Int64.div (Int64.sub
newvals.cache_misses_raw oldvals.cache_misses_raw)
+ (Int64.of_float (newvals.time -.
oldvals.time))))
+ ~ty:Rrd.Gauge ~min:0.0 ~default:true ()) ]
+ in
+
+ match !last_cache_stats,cache_sr_opt with
+ | None, None ->
+ []
+ | None, Some cache_sr ->
+ let stats = do_read cache_sr in
+ last_cache_stats := Some stats;
+ []
+ | Some oldstats, None ->
+ last_cache_stats := None;
+ []
+ | Some oldstats, Some cache_sr ->
+ if timestamp -. oldstats.time > 55.0 then begin
+ let newstats = do_read cache_sr in
+ last_cache_stats := Some newstats;
+ let dss = get_dss cache_sr oldstats newstats in
+ cached_cache_dss := dss;
+ dss
+ end else !cached_cache_dss
+
let read_all_dom0_stats __context =
let handle_exn log f default =
@@ -452,6 +523,7 @@
handle_exn "read_mem_metrics" (fun ()->read_mem_metrics xc) [];
vcpus;
vifs;
+ handle_exn "cache_stats" (fun () -> read_cache_stats timestamp) [];
handle_exn "update_pcpus" (fun ()->update_pcpus xc) [];
handle_exn "update_vbds" (fun ()->update_vbds domains) [];
handle_exn "update_loadavg" (fun ()-> [ update_loadavg () ]) [];
diff -r 243ef81d48f7 -r c9096a7ecb48 ocaml/xapi/xapi_host.ml
--- a/ocaml/xapi/xapi_host.ml
+++ b/ocaml/xapi/xapi_host.ml
@@ -1376,7 +1376,8 @@
let pbd_host = Db.PBD.get_host ~__context ~self:(List.hd pbds)
in
if pbd_host <> host then raise (Api_errors.Server_error
(Api_errors.host_cannot_see_SR,[Ref.string_of host; Ref.string_of sr]));
Db.Host.set_local_cache_sr ~__context ~self:host ~value:sr;
- Db.SR.set_local_cache_enabled ~__context ~self:sr ~value:true
+ Db.SR.set_local_cache_enabled ~__context ~self:sr ~value:true;
+ Monitor.set_cache_sr (Db.SR.get_uuid ~__context ~self:sr);
end else begin
raise (Api_errors.Server_error
(Api_errors.sr_operation_not_supported,[]))
end
@@ -1385,6 +1386,7 @@
assert_bacon_mode ~__context ~host;
let sr = Db.Host.get_local_cache_sr ~__context ~self:host in
Db.Host.set_local_cache_sr ~__context ~self:host ~value:Ref.null;
+ Monitor.unset_cache_sr ();
try Db.SR.set_local_cache_enabled ~__context ~self:sr ~value:false with
_ -> ()
xen-api2.hg-2.patch
Description: Text Data
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