[metricbeat] first pass at adding vmstats to system/memory (elastic#1…

…3322)

*  adding vmstats to system/memory

CHANGELOG.next.asciidoc

@@ -342,6 +342,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Add `metricset.period` field with the configured fetching period. {pull}13242[13242] {issue}12616[12616]
 - Add rate metrics for ec2 metricset. {pull}13203[13203]
 - Add Performance metricset to Oracle module {pull}12547[12547]
+- Add proc/vmstat data to the system/memory metricset on linux {pull}13322[13322]
 
 *Packetbeat*
 

NOTICE.txt

@@ -820,8 +820,8 @@ Apache License 2.0
 
 --------------------------------------------------------------------
 Dependency: github.com/elastic/go-sysinfo
-Version: v1.0.2
-Revision: 06c1f463545498d8f4b378d4dcf3171794c28537
+Version: v1.1.0
+Revision: 51d9d1362d77a4792dfb39a7a19f056cdf1b9840
 License type (autodetected): Apache-2.0
 ./vendor/github.com/elastic/go-sysinfo/LICENSE.txt:
 --------------------------------------------------------------------

libbeat/metric/system/memory/memory.go

@@ -20,8 +20,12 @@
 package memory
 
 import (
+	"github.com/pkg/errors"
+
 	"github.com/elastic/beats/libbeat/common"
 	"github.com/elastic/beats/libbeat/logp"
+	sysinfo "github.com/elastic/go-sysinfo"
+	sysinfotypes "github.com/elastic/go-sysinfo/types"
 	sigar "github.com/elastic/gosigar"
 )
 
@@ -148,3 +152,20 @@ func AddHugeTLBPagesPercentage(s *HugeTLBPagesStat) {
 	perc := float64(s.Total-s.Free+s.Reserved) / float64(s.Total)
 	s.UsedPercent = common.Round(perc, common.DefaultDecimalPlacesCount)
 }
+
+// GetVMStat gets linux vmstat metrics
+func GetVMStat() (*sysinfotypes.VMStatInfo, error) {
+	h, err := sysinfo.Host()
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to read self process information")
+	}
+	if vmstatHandle, ok := h.(sysinfotypes.VMStat); ok {
+		info, err := vmstatHandle.VMStat()
+		if err != nil {
+			return nil, errors.Wrap(err, "error getting VMStat info")
+		}
+		return info, nil
+	}
+	return nil, nil
+
+}

metricbeat/docs/fields.asciidoc

@@ -28371,6 +28371,42 @@ format: bytes
 
 --
 
+*`system.memory.swap.out.pages`*::
++
+--
+count of pages swapped out
+
+type: long
+
+--
+
+*`system.memory.swap.in.pages`*::
++
+--
+count of pages swapped in
+
+type: long
+
+--
+
+*`system.memory.swap.readahead.pages`*::
++
+--
+swap readahead pages
+
+type: long
+
+--
+
+*`system.memory.swap.readahead.cached`*::
++
+--
+swap readahead cache hits
+
+type: long
+
+--
+
 *`system.memory.swap.used.pct`*::
 +
 --
@@ -28473,6 +28509,30 @@ format: bytes
 
 --
 
+[float]
+=== swap.out
+
+huge pages swapped out
+
+
+*`system.memory.hugepages.swap.out.pages`*::
++
+--
+pages swapped out
+
+type: long
+
+--
+
+*`system.memory.hugepages.swap.out.fallback`*::
++
+--
+Count of huge pages that must be split before swapout
+
+type: long
+
+--
+
 [float]
 === network
 

metricbeat/module/system/memory/_meta/data.json

@@ -1,9 +1,5 @@
 {
     "@timestamp": "2017-10-12T08:05:34.853Z",
-    "agent": {
-        "hostname": "host.example.com",
-        "name": "host.example.com"
-    },
     "event": {
         "dataset": "system.memory",
         "duration": 115000,
@@ -18,36 +14,52 @@
     "system": {
         "memory": {
             "actual": {
-                "free": 4974256128,
+                "free": 671084544,
                 "used": {
-                    "bytes": 11597463552,
-                    "pct": 0.6998
+                    "bytes": 362037248,
+                    "pct": 0.3504
                 }
             },
-            "free": 1320112128,
+            "free": 340848640,
             "hugepages": {
                 "default_size": 2097152,
                 "free": 0,
                 "reserved": 0,
                 "surplus": 0,
+                "swap": {
+                    "out": {
+                        "fallback": 0,
+                        "pages": 0
+                    }
+                },
                 "total": 0,
                 "used": {
                     "bytes": 0,
                     "pct": 0
                 }
             },
             "swap": {
-                "free": 3482378240,
-                "total": 8589930496,
+                "free": 0,
+                "in": {
+                    "pages": 0
+                },
+                "out": {
+                    "pages": 0
+                },
+                "readahead": {
+                    "cached": 0,
+                    "pages": 0
+                },
+                "total": 0,
                 "used": {
-                    "bytes": 5107552256,
-                    "pct": 0.5946
+                    "bytes": 0,
+                    "pct": 0
                 }
             },
-            "total": 16571719680,
+            "total": 1033121792,
             "used": {
-                "bytes": 15251607552,
-                "pct": 0.9203
+                "bytes": 692273152,
+                "pct": 0.6701
             }
         }
     }

metricbeat/module/system/memory/_meta/fields.yml

@@ -79,6 +79,22 @@
           description: >
             Available swap memory.
 
+        - name: out.pages
+          type: long
+          description: count of pages swapped out
+
+        - name: in.pages
+          type: long
+          description: count of pages swapped in
+
+        - name: readahead.pages
+          type: long
+          description: swap readahead pages
+
+        - name: readahead.cached
+          type: long
+          description: swap readahead cache hits
+
         - name: used.pct
           type: scaled_float
           format: percent
@@ -131,3 +147,14 @@
           format: bytes
           description: >
             Default size for huge pages.
+
+        - name: swap.out
+          type: group
+          description: huge pages swapped out
+          fields:
+            - name: pages
+              type: long
+              description: pages swapped out
+            - name: fallback
+              type: long
+              description: Count of huge pages that must be split before swapout

metricbeat/module/system/memory/memory.go

@@ -75,6 +75,11 @@ func (m *MetricSet) Fetch(r mb.ReporterV2) error {
 		},
 	}
 
+	vmstat, err := mem.GetVMStat()
+	if err != nil {
+		return errors.Wrap(err, "VMStat")
+	}
+
 	swap := common.MapStr{
 		"total": swapStat.Total,
 		"used": common.MapStr{
@@ -83,6 +88,24 @@ func (m *MetricSet) Fetch(r mb.ReporterV2) error {
 		},
 		"free": swapStat.Free,
 	}
+
+	if vmstat != nil {
+		// Swap in and swap out numbers
+		swap["in"] = common.MapStr{
+			"pages": vmstat.Pswpin,
+		}
+		swap["out"] = common.MapStr{
+			"pages": vmstat.Pswpout,
+		}
+		//Swap readahead
+		//See https://www.kernel.org/doc/ols/2007/ols2007v2-pages-273-284.pdf
+		swap["readahead"] = common.MapStr{
+			"pages":  vmstat.SwapRa,
+			"cached": vmstat.SwapRaHit,
+		}
+
+	}
+
 	memory["swap"] = swap
 
 	hugePagesStat, err := mem.GetHugeTLBPages()
@@ -91,7 +114,7 @@ func (m *MetricSet) Fetch(r mb.ReporterV2) error {
 	}
 	if hugePagesStat != nil {
 		mem.AddHugeTLBPagesPercentage(hugePagesStat)
-		memory["hugepages"] = common.MapStr{
+		thp := common.MapStr{
 			"total": hugePagesStat.Total,
 			"used": common.MapStr{
 				"bytes": hugePagesStat.TotalAllocatedSize,
@@ -102,6 +125,15 @@ func (m *MetricSet) Fetch(r mb.ReporterV2) error {
 			"surplus":      hugePagesStat.Surplus,
 			"default_size": hugePagesStat.DefaultSize,
 		}
+		if vmstat != nil {
+			thp["swap"] = common.MapStr{
+				"out": common.MapStr{
+					"pages":    vmstat.ThpSwpout,
+					"fallback": vmstat.ThpSwpoutFallback,
+				},
+			}
+		}
+		memory["hugepages"] = thp
 	}
 
 	r.Event(mb.Event{