ZFS Collector: Add fm functionality

Signed-Off-By: Joe Handzik <joseph.t.handzik@hpe.com>

collector/fixtures/e2e-output.txt

@@ -2383,6 +2383,18 @@ node_zfsFetch_stride_hits 7.06799e+06
 # HELP node_zfsFetch_stride_misses kstat.zfs.misc.zfetchstats.stride_misses
 # TYPE node_zfsFetch_stride_misses untyped
 node_zfsFetch_stride_misses 0
+# HELP node_zfsFm_erpt-dropped kstat.zfs.misc.fm.erpt-dropped
+# TYPE node_zfsFm_erpt-dropped untyped
+node_zfsFm_erpt-dropped 18
+# HELP node_zfsFm_erpt-set-failed kstat.zfs.misc.fm.erpt-set-failed
+# TYPE node_zfsFm_erpt-set-failed untyped
+node_zfsFm_erpt-set-failed 0
+# HELP node_zfsFm_fmri-set-failed kstat.zfs.misc.fm.fmri-set-failed
+# TYPE node_zfsFm_fmri-set-failed untyped
+node_zfsFm_fmri-set-failed 0
+# HELP node_zfsFm_payload-set-failed kstat.zfs.misc.fm.payload-set-failed
+# TYPE node_zfsFm_payload-set-failed untyped
+node_zfsFm_payload-set-failed 0
 # HELP node_zfsVdevCache_delegations kstat.zfs.misc.vdev_cache_stats.delegations
 # TYPE node_zfsVdevCache_delegations untyped
 node_zfsVdevCache_delegations 40

collector/fixtures/proc/spl/kstat/zfs/fm

@@ -0,0 +1,6 @@
+0 1 0x01 4 192 8007255140 354329591145385
+name                            type data
+erpt-dropped                    4    18
+erpt-set-failed                 4    0
+fmri-set-failed                 4    0
+payload-set-failed              4    0

collector/zfs.go

@@ -35,6 +35,7 @@ type zfsSubsystemName string
 
 const (
 	arc            = zfsSubsystemName("zfsArc")
+	fm             = zfsSubsystemName("zfsFm")
 	vdevCache      = zfsSubsystemName("zfsVdevCache")
 	xuio           = zfsSubsystemName("zfsXuio")
 	zfetch         = zfsSubsystemName("zfsFetch")
@@ -91,6 +92,10 @@ func (c *zfsCollector) Update(ch chan<- prometheus.Metric) (err error) {
 	err = c.updateXuioStats(ch)
 	if err != nil { return err }
 
+	// Fm
+	err = c.updateFm(ch)
+	if err != nil { return err }
+
 	// Pool stats
 	return c.updatePoolStats(ch)
 }

collector/zfs_linux.go

@@ -29,6 +29,7 @@ import (
 const (
 	zfsProcpathBase      = "spl/kstat/zfs/"
 	zfsArcstatsExt       = "arcstats"
+	zfsFmExt             = "fm"
 	zfsFetchstatsExt     = "zfetchstats"
 	zfsVdevCacheStatsExt = "vdev_cache_stats"
 	zfsXuioStatsExt      = "xuio_stats"
@@ -104,6 +105,18 @@ func (c *zfsCollector) updateXuioStats(ch chan<- prometheus.Metric) (err error)
 	})
 }
 
+func (c *zfsCollector) updateFm(ch chan<- prometheus.Metric) (err error) {
+	file, err := c.openProcFile(filepath.Join(zfsProcpathBase, zfsFmExt))
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	return c.parseProcfsFile(file, zfsFmExt, func(s zfsSysctl, v zfsMetricValue) {
+		ch <- c.constSysctlMetric(fm, s, v)
+	})
+}
+
 func (c *zfsCollector) parseProcfsFile(reader io.Reader, fmt_ext string, handler func(zfsSysctl, zfsMetricValue)) (err error) {
 	scanner := bufio.NewScanner(reader)
 

collector/zfs_linux_test.go

@@ -197,3 +197,39 @@ func TestXuioStatsParsing(t *testing.T) {
 		t.Fatal("XuioStats parsing handler was not called for some expected sysctls")
 	}
 }
+
+func TestFmParsing(t *testing.T) {
+	fmFile, err := os.Open("fixtures/proc/spl/kstat/zfs/fm")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fmFile.Close()
+
+	c := zfsCollector{}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	handlerCalled := false
+	err = c.parseProcfsFile(fmFile, "fm", func(s zfsSysctl, v zfsMetricValue) {
+
+		if s != zfsSysctl("kstat.zfs.misc.fm.erpt-dropped") {
+			return
+		}
+
+		handlerCalled = true
+
+		if v != zfsMetricValue(18) {
+			t.Fatalf("Incorrect value parsed from procfs data")
+		}
+
+	})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !handlerCalled {
+		t.Fatal("Fm parsing handler was not called for some expected sysctls")
+	}
+}