ZFS Collector: Add zil functionality

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

collector/fixtures/e2e-output.txt

@@ -2383,6 +2383,45 @@ 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_zfsZil_zil_commit_count kstat.zfs.misc.zil.zil_commit_count
+# TYPE node_zfsZil_zil_commit_count untyped
+node_zfsZil_zil_commit_count 10
+# HELP node_zfsZil_zil_commit_writer_count kstat.zfs.misc.zil.zil_commit_writer_count
+# TYPE node_zfsZil_zil_commit_writer_count untyped
+node_zfsZil_zil_commit_writer_count 0
+# HELP node_zfsZil_zil_itx_copied_bytes kstat.zfs.misc.zil.zil_itx_copied_bytes
+# TYPE node_zfsZil_zil_itx_copied_bytes untyped
+node_zfsZil_zil_itx_copied_bytes 0
+# HELP node_zfsZil_zil_itx_copied_count kstat.zfs.misc.zil.zil_itx_copied_count
+# TYPE node_zfsZil_zil_itx_copied_count untyped
+node_zfsZil_zil_itx_copied_count 0
+# HELP node_zfsZil_zil_itx_count kstat.zfs.misc.zil.zil_itx_count
+# TYPE node_zfsZil_zil_itx_count untyped
+node_zfsZil_zil_itx_count 0
+# HELP node_zfsZil_zil_itx_indirect_bytes kstat.zfs.misc.zil.zil_itx_indirect_bytes
+# TYPE node_zfsZil_zil_itx_indirect_bytes untyped
+node_zfsZil_zil_itx_indirect_bytes 0
+# HELP node_zfsZil_zil_itx_indirect_count kstat.zfs.misc.zil.zil_itx_indirect_count
+# TYPE node_zfsZil_zil_itx_indirect_count untyped
+node_zfsZil_zil_itx_indirect_count 0
+# HELP node_zfsZil_zil_itx_metaslab_normal_bytes kstat.zfs.misc.zil.zil_itx_metaslab_normal_bytes
+# TYPE node_zfsZil_zil_itx_metaslab_normal_bytes untyped
+node_zfsZil_zil_itx_metaslab_normal_bytes 0
+# HELP node_zfsZil_zil_itx_metaslab_normal_count kstat.zfs.misc.zil.zil_itx_metaslab_normal_count
+# TYPE node_zfsZil_zil_itx_metaslab_normal_count untyped
+node_zfsZil_zil_itx_metaslab_normal_count 0
+# HELP node_zfsZil_zil_itx_metaslab_slog_bytes kstat.zfs.misc.zil.zil_itx_metaslab_slog_bytes
+# TYPE node_zfsZil_zil_itx_metaslab_slog_bytes untyped
+node_zfsZil_zil_itx_metaslab_slog_bytes 0
+# HELP node_zfsZil_zil_itx_metaslab_slog_count kstat.zfs.misc.zil.zil_itx_metaslab_slog_count
+# TYPE node_zfsZil_zil_itx_metaslab_slog_count untyped
+node_zfsZil_zil_itx_metaslab_slog_count 0
+# HELP node_zfsZil_zil_itx_needcopy_bytes kstat.zfs.misc.zil.zil_itx_needcopy_bytes
+# TYPE node_zfsZil_zil_itx_needcopy_bytes untyped
+node_zfsZil_zil_itx_needcopy_bytes 0
+# HELP node_zfsZil_zil_itx_needcopy_count kstat.zfs.misc.zil.zil_itx_needcopy_count
+# TYPE node_zfsZil_zil_itx_needcopy_count untyped
+node_zfsZil_zil_itx_needcopy_count 0
 # HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.
 # TYPE process_cpu_seconds_total counter
 # HELP process_max_fds Maximum number of open file descriptors.

collector/fixtures/proc/spl/kstat/zfs/zil

@@ -0,0 +1,15 @@
+7 1 0x01 13 624 8012538347 351689526932992
+name                            type data
+zil_commit_count                4    10
+zil_commit_writer_count         4    0
+zil_itx_count                   4    0
+zil_itx_indirect_count          4    0
+zil_itx_indirect_bytes          4    0
+zil_itx_copied_count            4    0
+zil_itx_copied_bytes            4    0
+zil_itx_needcopy_count          4    0
+zil_itx_needcopy_bytes          4    0
+zil_itx_metaslab_normal_count   4    0
+zil_itx_metaslab_normal_bytes   4    0
+zil_itx_metaslab_slog_count     4    0
+zil_itx_metaslab_slog_bytes     4    0

collector/zfs.go

@@ -36,6 +36,7 @@ type zfsSubsystemName string
 const (
 	arc            = zfsSubsystemName("zfsArc")
 	zfetch         = zfsSubsystemName("zfsFetch")
+	zil            = zfsSubsystemName("zfsZil")
 	zpoolSubsystem = zfsSubsystemName("zfsPool")
 )
 
@@ -76,6 +77,10 @@ func (c *zfsCollector) Update(ch chan<- prometheus.Metric) (err error) {
 	err = c.updateZfetchstats(ch)
 	if err != nil { return err }
 
+	// Zil
+	err = c.updateZil(ch)
+	if err != nil { return err }
+
 	// Pool stats
 	return c.updatePoolStats(ch)
 }

collector/zfs_linux.go

@@ -30,6 +30,7 @@ const (
 	zfsProcpathBase  = "spl/kstat/zfs/"
 	zfsArcstatsExt   = "arcstats"
 	zfsFetchstatsExt = "zfetchstats"
+	zfsZilExt        = "zil"
 )
 
 func (c *zfsCollector) openProcFile(path string) (file *os.File, err error) {
@@ -65,6 +66,18 @@ func (c *zfsCollector) updateZfetchstats(ch chan<- prometheus.Metric) (err error
 	})
 }
 
+func (c *zfsCollector) updateZil(ch chan<- prometheus.Metric) (err error) {
+	file, err := c.openProcFile(filepath.Join(zfsProcpathBase, zfsZilExt))
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	return c.parseProcfsFile(file, zfsZilExt, func(s zfsSysctl, v zfsMetricValue) {
+		ch <- c.constSysctlMetric(zil, 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

@@ -89,3 +89,39 @@ func TestZfetchstatsParsing(t *testing.T) {
 		t.Fatal("Zfetchstats parsing handler was not called for some expected sysctls")
 	}
 }
+
+func TestZilParsing(t *testing.T) {
+	zilFile, err := os.Open("fixtures/proc/spl/kstat/zfs/zil")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer zilFile.Close()
+
+	c := zfsCollector{}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	handlerCalled := false
+	err = c.parseProcfsFile(zilFile, "zil", func(s zfsSysctl, v zfsMetricValue) {
+
+		if s != zfsSysctl("kstat.zfs.misc.zil.zil_commit_count") {
+			return
+		}
+
+		handlerCalled = true
+
+		if v != zfsMetricValue(10) {
+			t.Fatalf("Incorrect value parsed from procfs data")
+		}
+
+	})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !handlerCalled {
+		t.Fatal("Zil parsing handler was not called for some expected sysctls")
+	}
+}