Add kstat-based Solaris metrics (#1197)

* collector/loadavg_solaris.go: Use libkstat to gather load averages.
* go.mod: Added go-kstat.
* boot_time_solaris.go: Added.
* cpu_solaris.go: Added.
* README.md: Updated entries for Solaris.
* collector/zfs_solaris.go: Added.
* CHANGELOG.md: Added note about kstat-based Solaris metrics.

Signed-off-by: Jonathan Davies <jpds@protonmail.com>

9 files changed, 583 insertions, 14 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a01241b..86d380a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@
 * [CHANGE] Add a limit to the number of in-flight requests #1166
 * [ENHANCEMENT] Add Infiniband counters #1120
 * [FEATURE] Add a flag to disable exporter metrics #1148
+* [FEATURE] Add kstat-based Solaris metrics for boottime, cpu and zfs collectors #1197
 
 ## 0.17.0 / 2018-11-30
 
diff --git a/README.md b/README.md
index 4416325..9066d85 100644
--- a/README.md
+++ b/README.md
@@ -29,9 +29,9 @@ Name     | Description | OS
 arp | Exposes ARP statistics from `/proc/net/arp`. | Linux
 bcache | Exposes bcache statistics from `/sys/fs/bcache/`. | Linux
 bonding | Exposes the number of configured and active slaves of Linux bonding interfaces. | Linux
-boottime | Exposes system boot time derived from the `kern.boottime` sysctl. | Darwin, Dragonfly, FreeBSD, NetBSD, OpenBSD
+boottime | Exposes system boot time derived from the `kern.boottime` sysctl. | Darwin, Dragonfly, FreeBSD, NetBSD, OpenBSD, Solaris
 conntrack | Shows conntrack statistics (does nothing if no `/proc/sys/net/netfilter/` present). | Linux
-cpu | Exposes CPU statistics | Darwin, Dragonfly, FreeBSD, Linux
+cpu | Exposes CPU statistics | Darwin, Dragonfly, FreeBSD, Linux, Solaris
 diskstats | Exposes disk I/O statistics. | Darwin, Linux
 edac | Exposes error detection and correction statistics. | Linux
 entropy | Exposes available entropy. | Linux
@@ -57,7 +57,7 @@ timex | Exposes selected adjtimex(2) system call stats. | Linux
 uname | Exposes system information as provided by the uname system call. | Linux
 vmstat | Exposes statistics from `/proc/vmstat`. | Linux
 xfs | Exposes XFS runtime statistics. | Linux (kernel 4.4+)
-zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics. | [Linux](http://zfsonlinux.org/)
+zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics. | [Linux](http://zfsonlinux.org/), Solaris
 
 ### Disabled by default
 
diff --git a/collector/boot_time_solaris.go b/collector/boot_time_solaris.go
new file mode 100644
index 0000000..ea0c50a
--- /dev/null
+++ b/collector/boot_time_solaris.go
@@ -0,0 +1,66 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build solaris
+// +build !noboottime
+
+package collector
+
+import (
+        "github.com/prometheus/client_golang/prometheus"
+        "github.com/siebenmann/go-kstat"
+)
+
+type bootTimeCollector struct {
+        boottime typedDesc
+}
+
+func init() {
+        registerCollector("boottime", defaultEnabled, newBootTimeCollector)
+}
+
+func newBootTimeCollector() (Collector, error) {
+        return &bootTimeCollector{
+                boottime: typedDesc{
+                        prometheus.NewDesc(
+                                prometheus.BuildFQName(namespace, "", "boot_time_seconds"),
+                                "Unix time of last boot, including microseconds.",
+                                nil, nil,
+                        ), prometheus.GaugeValue},
+        }, nil
+}
+
+// newBootTimeCollector returns a new Collector exposing system boot time on Solaris systems.
+// Update pushes boot time onto ch
+func (c *bootTimeCollector) Update(ch chan<- prometheus.Metric) error {
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        ks, err := tok.Lookup("unix", 0, "system_misc")
+        if err != nil {
+                return err
+        }
+
+        v, err := ks.GetNamed("boot_time")
+        if err != nil {
+                return err
+        }
+
+        ch <- c.boottime.mustNewConstMetric(float64(v.UintVal))
+
+        return nil
+}
diff --git a/collector/cpu_solaris.go b/collector/cpu_solaris.go
new file mode 100644
index 0000000..f60aeb3
--- /dev/null
+++ b/collector/cpu_solaris.go
@@ -0,0 +1,140 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build solaris
+// +build !nocpu
+
+package collector
+
+import (
+        "fmt"
+        "strconv"
+
+        "github.com/prometheus/client_golang/prometheus"
+        "github.com/siebenmann/go-kstat"
+)
+
+// #include <unistd.h>
+import "C"
+
+type cpuCollector struct {
+        cpu        typedDesc
+        cpuFreq    *prometheus.Desc
+        cpuFreqMax *prometheus.Desc
+}
+
+func init() {
+        registerCollector("cpu", defaultEnabled, NewCpuCollector)
+}
+
+func NewCpuCollector() (Collector, error) {
+        return &cpuCollector{
+                cpu: typedDesc{nodeCPUSecondsDesc, prometheus.CounterValue},
+                cpuFreq: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "frequency_hertz"),
+                        "Current cpu thread frequency in hertz.",
+                        []string{"cpu"}, nil,
+                ),
+                cpuFreqMax: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "frequency_max_hertz"),
+                        "Maximum cpu thread frequency in hertz.",
+                        []string{"cpu"}, nil,
+                ),
+        }, nil
+}
+
+func (c *cpuCollector) Update(ch chan<- prometheus.Metric) error {
+        if err := c.updateCPUstats(ch); err != nil {
+                return err
+        }
+        if err := c.updateCPUfreq(ch); err != nil {
+                return err
+        }
+        return nil
+}
+
+func (c *cpuCollector) updateCPUstats(ch chan<- prometheus.Metric) error {
+        ncpus := C.sysconf(C._SC_NPROCESSORS_ONLN)
+
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        for cpu := 0; cpu < int(ncpus); cpu++ {
+                ksCPU, err := tok.Lookup("cpu", cpu, "sys")
+                if err != nil {
+                        return err
+                }
+
+                for k, v := range map[string]string{
+                        "idle":   "cpu_ticks_idle",
+                        "kernel": "cpu_ticks_kernel",
+                        "user":   "cpu_ticks_user",
+                        "wait":   "cpu_ticks_wait",
+                } {
+                        kstatValue, err := ksCPU.GetNamed(v)
+                        if err != nil {
+                                return err
+                        }
+
+                        ch <- c.cpu.mustNewConstMetric(float64(kstatValue.UintVal), strconv.Itoa(cpu), k)
+                }
+        }
+        return nil
+}
+
+func (c *cpuCollector) updateCPUfreq(ch chan<- prometheus.Metric) error {
+        ncpus := C.sysconf(C._SC_NPROCESSORS_ONLN)
+
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        for cpu := 0; cpu < int(ncpus); cpu++ {
+                ksCPUInfo, err := tok.Lookup("cpu_info", cpu, fmt.Sprintf("cpu_info%d", cpu))
+                if err != nil {
+                        return err
+                }
+                cpuFreqV, err := ksCPUInfo.GetNamed("current_clock_Hz")
+                if err != nil {
+                        return err
+                }
+
+                cpuFreqMaxV, err := ksCPUInfo.GetNamed("clock_MHz")
+                if err != nil {
+                        return err
+                }
+
+                lcpu := strconv.Itoa(cpu)
+                ch <- prometheus.MustNewConstMetric(
+                        c.cpuFreq,
+                        prometheus.GaugeValue,
+                        float64(cpuFreqV.UintVal),
+                        lcpu,
+                )
+                // Multiply by 1e+6 to convert MHz to Hz.
+                ch <- prometheus.MustNewConstMetric(
+                        c.cpuFreqMax,
+                        prometheus.GaugeValue,
+                        float64(cpuFreqMaxV.IntVal)*1e+6,
+                        lcpu,
+                )
+        }
+        return nil
+}
diff --git a/collector/loadavg_solaris.go b/collector/loadavg_solaris.go
index 42ddc59..1ef8d31 100644
--- a/collector/loadavg_solaris.go
+++ b/collector/loadavg_solaris.go
@@ -16,21 +16,49 @@
 package collector
 
 import (
-        "errors"
+        "fmt"
+        "strconv"
+
+        "github.com/siebenmann/go-kstat"
 )
 
-/*
-// Ensure "hrtime_t" is defined for sys/loadavg.h
-#include <sys/time.h>
-#include <sys/loadavg.h>
-*/
+// #include <sys/param.h>
 import "C"
 
+func kstatToFloat(ks *kstat.KStat, kstatKey string) float64 {
+        kstatValue, err := ks.GetNamed(kstatKey)
+
+        if err != nil {
+                panic(err)
+        }
+
+        kstatLoadavg, err := strconv.ParseFloat(
+                fmt.Sprintf("%.2f", float64(kstatValue.UintVal)/C.FSCALE), 64)
+
+        if err != nil {
+                panic(err)
+        }
+
+        return kstatLoadavg
+}
+
 func getLoad() ([]float64, error) {
-        var loadavg [3]C.double
-        samples := C.getloadavg(&loadavg[0], 3)
-        if samples != 3 {
-                return nil, errors.New("failed to get load average")
+        tok, err := kstat.Open()
+        if err != nil {
+                panic(err)
         }
-        return []float64{float64(loadavg[0]), float64(loadavg[1]), float64(loadavg[2])}, nil
+
+        defer tok.Close()
+
+        ks, err := tok.Lookup("unix", 0, "system_misc")
+
+        if err != nil {
+                panic(err)
+        }
+
+        loadavg1Min := kstatToFloat(ks, "avenrun_1min")
+        loadavg5Min := kstatToFloat(ks, "avenrun_5min")
+        loadavg15Min := kstatToFloat(ks, "avenrun_15min")
+
+        return []float64{loadavg1Min, loadavg5Min, loadavg15Min}, nil
 }
diff --git a/collector/zfs_solaris.go b/collector/zfs_solaris.go
new file mode 100644
index 0000000..5bf2235
--- /dev/null
+++ b/collector/zfs_solaris.go
@@ -0,0 +1,329 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build solaris
+
+package collector
+
+import (
+        "strings"
+
+        "github.com/prometheus/client_golang/prometheus"
+        "github.com/siebenmann/go-kstat"
+)
+
+type zfsCollector struct {
+        abdstatsLinearCount          *prometheus.Desc
+        abdstatsLinearDataSize       *prometheus.Desc
+        abdstatsScatterChunkWaste    *prometheus.Desc
+        abdstatsScatterCount         *prometheus.Desc
+        abdstatsScatterDataSize      *prometheus.Desc
+        abdstatsStructSize           *prometheus.Desc
+        arcstatsAnonSize             *prometheus.Desc
+        arcstatsC                    *prometheus.Desc
+        arcstatsCMax                 *prometheus.Desc
+        arcstatsCMin                 *prometheus.Desc
+        arcstatsDataSize             *prometheus.Desc
+        arcstatsDemandDataHits       *prometheus.Desc
+        arcstatsDemandDataMisses     *prometheus.Desc
+        arcstatsDemandMetadataHits   *prometheus.Desc
+        arcstatsDemandMetadataMisses *prometheus.Desc
+        arcstatsHeaderSize           *prometheus.Desc
+        arcstatsHits                 *prometheus.Desc
+        arcstatsMisses               *prometheus.Desc
+        arcstatsMFUGhostHits         *prometheus.Desc
+        arcstatsMFUGhostSize         *prometheus.Desc
+        arcstatsMFUSize              *prometheus.Desc
+        arcstatsMRUGhostHits         *prometheus.Desc
+        arcstatsMRUGhostSize         *prometheus.Desc
+        arcstatsMRUSize              *prometheus.Desc
+        arcstatsOtherSize            *prometheus.Desc
+        arcstatsP                    *prometheus.Desc
+        arcstatsSize                 *prometheus.Desc
+        zfetchstatsHits              *prometheus.Desc
+        zfetchstatsMisses            *prometheus.Desc
+}
+
+const (
+        zfsCollectorSubsystem = "zfs"
+)
+
+func init() {
+        registerCollector("zfs", defaultEnabled, NewZfsCollector)
+}
+
+func NewZfsCollector() (Collector, error) {
+        return &zfsCollector{
+                abdstatsLinearCount: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_linear_count_total"),
+                        "ZFS ARC buffer data linear count", nil, nil,
+                ),
+                abdstatsLinearDataSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_linear_data_bytes"),
+                        "ZFS ARC buffer data linear data size", nil, nil,
+                ),
+                abdstatsScatterChunkWaste: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_scatter_chunk_waste_bytes"),
+                        "ZFS ARC buffer data scatter chunk waste", nil, nil,
+                ),
+                abdstatsScatterCount: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_scatter_count_total"),
+                        "ZFS ARC buffer data scatter count", nil, nil,
+                ),
+                abdstatsScatterDataSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_scatter_data_bytes"),
+                        "ZFS ARC buffer data scatter data size", nil, nil,
+                ),
+                abdstatsStructSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "abdstats_struct_bytes"),
+                        "ZFS ARC buffer data struct size", nil, nil,
+                ),
+                arcstatsAnonSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_anon_bytes"),
+                        "ZFS ARC anon size", nil, nil,
+                ),
+                arcstatsC: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_c_bytes"),
+                        "ZFS ARC target size", nil, nil,
+                ),
+                arcstatsCMax: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_c_max_bytes"),
+                        "ZFS ARC maximum size", nil, nil,
+                ),
+                arcstatsCMin: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_c_min_bytes"),
+                        "ZFS ARC minimum size", nil, nil,
+                ),
+                arcstatsDataSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_data_bytes"),
+                        "ZFS ARC data size", nil, nil,
+                ),
+                arcstatsDemandDataHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_demand_data_hits_total"),
+                        "ZFS ARC demand data hits", nil, nil,
+                ),
+                arcstatsDemandDataMisses: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_demand_data_misses_total"),
+                        "ZFS ARC demand data misses", nil, nil,
+                ),
+                arcstatsDemandMetadataHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_demand_metadata_hits_total"),
+                        "ZFS ARC demand metadata hits", nil, nil,
+                ),
+                arcstatsDemandMetadataMisses: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_demand_metadata_misses_total"),
+                        "ZFS ARC demand metadata misses", nil, nil,
+                ),
+                arcstatsHeaderSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_hdr_bytes"),
+                        "ZFS ARC header size", nil, nil,
+                ),
+                arcstatsHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_hits_total"),
+                        "ZFS ARC hits", nil, nil,
+                ),
+                arcstatsMisses: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_misses_total"),
+                        "ZFS ARC misses", nil, nil,
+                ),
+                arcstatsMFUGhostHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mfu_ghost_hits_total"),
+                        "ZFS ARC MFU ghost hits", nil, nil,
+                ),
+                arcstatsMFUGhostSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mfu_ghost_size"),
+                        "ZFS ARC MFU ghost size", nil, nil,
+                ),
+                arcstatsMFUSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mfu_bytes"),
+                        "ZFS ARC MFU size", nil, nil,
+                ),
+                arcstatsMRUGhostHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mru_ghost_hits_total"),
+                        "ZFS ARC MRU ghost hits", nil, nil,
+                ),
+                arcstatsMRUGhostSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mru_ghost_bytes"),
+                        "ZFS ARC MRU ghost size", nil, nil,
+                ),
+                arcstatsMRUSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_mru_bytes"),
+                        "ZFS ARC MRU size", nil, nil,
+                ),
+                arcstatsOtherSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_other_bytes"),
+                        "ZFS ARC other size", nil, nil,
+                ),
+                arcstatsP: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_p_bytes"),
+                        "ZFS ARC MRU target size", nil, nil,
+                ),
+                arcstatsSize: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "arcstats_size_bytes"),
+                        "ZFS ARC size", nil, nil,
+                ),
+                zfetchstatsHits: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "zfetchstats_hits_total"),
+                        "ZFS cache fetch hits", nil, nil,
+                ),
+                zfetchstatsMisses: prometheus.NewDesc(
+                        prometheus.BuildFQName(namespace, zfsCollectorSubsystem, "zfetchstats_misses_total"),
+                        "ZFS cache fetch misses", nil, nil,
+                ),
+        }, nil
+}
+
+func (c *zfsCollector) updateZfsAbdStats(ch chan<- prometheus.Metric) error {
+        var metricType prometheus.ValueType
+
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        ksZFSInfo, err := tok.Lookup("zfs", 0, "abdstats")
+        if err != nil {
+                return err
+        }
+
+        for k, v := range map[string]*prometheus.Desc{
+                "linear_cnt":          c.abdstatsLinearCount,
+                "linear_data_size":    c.abdstatsLinearDataSize,
+                "scatter_chunk_waste": c.abdstatsScatterChunkWaste,
+                "scatter_cnt":         c.abdstatsScatterCount,
+                "scatter_data_size":   c.abdstatsScatterDataSize,
+                "struct_size":         c.abdstatsStructSize,
+        } {
+                ksZFSInfoValue, err := ksZFSInfo.GetNamed(k)
+                if err != nil {
+                        return err
+                }
+
+                if strings.HasSuffix(k, "_cnt") {
+                        metricType = prometheus.CounterValue
+                } else {
+                        metricType = prometheus.GaugeValue
+                }
+
+                ch <- prometheus.MustNewConstMetric(
+                        v,
+                        metricType,
+                        float64(ksZFSInfoValue.UintVal),
+                )
+        }
+
+        return nil
+}
+
+func (c *zfsCollector) updateZfsArcStats(ch chan<- prometheus.Metric) error {
+        var metricType prometheus.ValueType
+
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        ksZFSInfo, err := tok.Lookup("zfs", 0, "arcstats")
+        if err != nil {
+                return err
+        }
+
+        for k, v := range map[string]*prometheus.Desc{
+                "anon_size":              c.arcstatsAnonSize,
+                "c":                      c.arcstatsC,
+                "c_max":                  c.arcstatsCMax,
+                "c_min":                  c.arcstatsCMin,
+                "data_size":              c.arcstatsDataSize,
+                "demand_data_hits":       c.arcstatsDemandDataHits,
+                "demand_data_misses":     c.arcstatsDemandDataMisses,
+                "demand_metadata_hits":   c.arcstatsDemandMetadataHits,
+                "demand_metadata_misses": c.arcstatsDemandMetadataMisses,
+                "hdr_size":               c.arcstatsHeaderSize,
+                "hits":                   c.arcstatsHits,
+                "misses":                 c.arcstatsMisses,
+                "mfu_ghost_hits":         c.arcstatsMFUGhostHits,
+                "mfu_ghost_size":         c.arcstatsMFUGhostSize,
+                "mfu_size":               c.arcstatsMFUSize,
+                "mru_ghost_hits":         c.arcstatsMRUGhostHits,
+                "mru_ghost_size":         c.arcstatsMRUGhostSize,
+                "mru_size":               c.arcstatsMRUSize,
+                "other_size":             c.arcstatsOtherSize,
+                "p":                      c.arcstatsP,
+                "size":                   c.arcstatsSize,
+        } {
+                ksZFSInfoValue, err := ksZFSInfo.GetNamed(k)
+                if err != nil {
+                        return err
+                }
+
+                if strings.HasSuffix(k, "_hits") || strings.HasSuffix(k, "_misses") {
+                        metricType = prometheus.CounterValue
+                } else {
+                        metricType = prometheus.GaugeValue
+                }
+
+                ch <- prometheus.MustNewConstMetric(
+                        v,
+                        metricType,
+                        float64(ksZFSInfoValue.UintVal),
+                )
+        }
+
+        return nil
+}
+
+func (c *zfsCollector) updateZfsFetchStats(ch chan<- prometheus.Metric) error {
+        tok, err := kstat.Open()
+        if err != nil {
+                return err
+        }
+
+        defer tok.Close()
+
+        ksZFSInfo, err := tok.Lookup("zfs", 0, "zfetchstats")
+
+        for k, v := range map[string]*prometheus.Desc{
+                "hits":   c.zfetchstatsHits,
+                "misses": c.zfetchstatsMisses,
+        } {
+                ksZFSInfoValue, err := ksZFSInfo.GetNamed(k)
+                if err != nil {
+                        return err
+                }
+
+                ch <- prometheus.MustNewConstMetric(
+                        v,
+                        prometheus.CounterValue,
+                        float64(ksZFSInfoValue.UintVal),
+                )
+        }
+
+        return nil
+}
+
+func (c *zfsCollector) Update(ch chan<- prometheus.Metric) error {
+        if err := c.updateZfsAbdStats(ch); err != nil {
+                return err
+        }
+        if err := c.updateZfsArcStats(ch); err != nil {
+                return err
+        }
+        if err := c.updateZfsFetchStats(ch); err != nil {
+                return err
+        }
+        return nil
+}
diff --git a/go.mod b/go.mod
index 223925a..8b80a61 100644
--- a/go.mod
+++ b/go.mod
@@ -22,6 +22,7 @@ require (
         github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
         github.com/prometheus/common v0.0.0-20181015124227-bcb74de08d37
         github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d
+        github.com/siebenmann/go-kstat v0.0.0-20160321171754-d34789b79745
         github.com/sirupsen/logrus v1.1.1 // indirect
         github.com/soundcloud/go-runit v0.0.0-20150630195641-06ad41a06c4a
         golang.org/x/crypto v0.0.0-20181009213950-7c1a557ab941 // indirect
diff --git a/go.sum b/go.sum
index 2de8dba..8fec81b 100644
--- a/go.sum
+++ b/go.sum
@@ -45,6 +45,8 @@ github.com/prometheus/common v0.0.0-20181015124227-bcb74de08d37 h1:Y7YdJ9Xb3MoQO
 github.com/prometheus/common v0.0.0-20181015124227-bcb74de08d37/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d h1:GoAlyOgbOEIFdaDqxJVlbOQ1DtGmZWs/Qau0hIlk+WQ=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/siebenmann/go-kstat v0.0.0-20160321171754-d34789b79745 h1:IuH7WumZNax0D+rEqmy2TyhKCzrtMGqbZO0b8rO00JA=
+github.com/siebenmann/go-kstat v0.0.0-20160321171754-d34789b79745/go.mod h1:G81aIFAMS9ECrwBYR9YxhlPjWgrItd+Kje78O6+uqm8=
 github.com/sirupsen/logrus v1.1.1 h1:VzGj7lhU7KEB9e9gMpAV/v5XT2NVSvLJhJLCWbnkgXg=
 github.com/sirupsen/logrus v1.1.1/go.mod h1:zrgwTnHtNr00buQ1vSptGe8m1f/BbgsPukg8qsT7A+A=
 github.com/soundcloud/go-runit v0.0.0-20150630195641-06ad41a06c4a h1:os5OBNhwOwybXZMNLqT96XqtjdTtwRFw2w08uluvNeI=
diff --git a/vendor/modules.txt b/vendor/modules.txt
index d048101..dbd7d5f 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -50,6 +50,8 @@ github.com/prometheus/procfs/nfs
 github.com/prometheus/procfs/sysfs
 github.com/prometheus/procfs/xfs
 github.com/prometheus/procfs/internal/util
+# github.com/siebenmann/go-kstat v0.0.0-20160321171754-d34789b79745
+github.com/siebenmann/go-kstat
 # github.com/sirupsen/logrus v1.1.1
 github.com/sirupsen/logrus
 # github.com/soundcloud/go-runit v0.0.0-20150630195641-06ad41a06c4a