ZFS Collector: Add xuio_stats functionality

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

collector/fixtures/e2e-output.txt

@@ -2392,6 +2392,24 @@ node_zfsVdevCache_hits 0
 # HELP node_zfsVdevCache_misses kstat.zfs.misc.vdev_cache_stats.misses
 # TYPE node_zfsVdevCache_misses untyped
 node_zfsVdevCache_misses 0
+# HELP node_zfsXuio_onloan_read_buf kstat.zfs.misc.xuio_stats.onloan_read_buf
+# TYPE node_zfsXuio_onloan_read_buf untyped
+node_zfsXuio_onloan_read_buf 32
+# HELP node_zfsXuio_onloan_write_buf kstat.zfs.misc.xuio_stats.onloan_write_buf
+# TYPE node_zfsXuio_onloan_write_buf untyped
+node_zfsXuio_onloan_write_buf 0
+# HELP node_zfsXuio_read_buf_copied kstat.zfs.misc.xuio_stats.read_buf_copied
+# TYPE node_zfsXuio_read_buf_copied untyped
+node_zfsXuio_read_buf_copied 0
+# HELP node_zfsXuio_read_buf_nocopy kstat.zfs.misc.xuio_stats.read_buf_nocopy
+# TYPE node_zfsXuio_read_buf_nocopy untyped
+node_zfsXuio_read_buf_nocopy 0
+# HELP node_zfsXuio_write_buf_copied kstat.zfs.misc.xuio_stats.write_buf_copied
+# TYPE node_zfsXuio_write_buf_copied untyped
+node_zfsXuio_write_buf_copied 0
+# HELP node_zfsXuio_write_buf_nocopy kstat.zfs.misc.xuio_stats.write_buf_nocopy
+# TYPE node_zfsXuio_write_buf_nocopy untyped
+node_zfsXuio_write_buf_nocopy 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

collector/fixtures/proc/spl/kstat/zfs/xuio_stats

@@ -0,0 +1,8 @@
+2 1 0x01 6 288 8009100742 353415816865654
+name                            type data
+onloan_read_buf                 4    32
+onloan_write_buf                4    0
+read_buf_copied                 4    0
+read_buf_nocopy                 4    0
+write_buf_copied                4    0
+write_buf_nocopy                4    0

collector/zfs.go

@@ -36,6 +36,7 @@ type zfsSubsystemName string
 const (
 	arc            = zfsSubsystemName("zfsArc")
 	vdevCache      = zfsSubsystemName("zfsVdevCache")
+	xuio           = zfsSubsystemName("zfsXuio")
 	zfetch         = zfsSubsystemName("zfsFetch")
 	zil            = zfsSubsystemName("zfsZil")
 	zpoolSubsystem = zfsSubsystemName("zfsPool")
@@ -86,6 +87,10 @@ func (c *zfsCollector) Update(ch chan<- prometheus.Metric) (err error) {
 	err = c.updateVdevCacheStats(ch)
 	if err != nil { return err }
 
+	// XuioStats
+	err = c.updateXuioStats(ch)
+	if err != nil { return err }
+
 	// Pool stats
 	return c.updatePoolStats(ch)
 }

collector/zfs_linux.go

@@ -31,6 +31,7 @@ const (
 	zfsArcstatsExt       = "arcstats"
 	zfsFetchstatsExt     = "zfetchstats"
 	zfsVdevCacheStatsExt = "vdev_cache_stats"
+	zfsXuioStatsExt      = "xuio_stats"
 	zfsZilExt            = "zil"
 )
 
@@ -91,6 +92,18 @@ func (c *zfsCollector) updateVdevCacheStats(ch chan<- prometheus.Metric) (err er
 	})
 }
 
+func (c *zfsCollector) updateXuioStats(ch chan<- prometheus.Metric) (err error) {
+	file, err := c.openProcFile(filepath.Join(zfsProcpathBase, zfsXuioStatsExt))
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	return c.parseProcfsFile(file, zfsXuioStatsExt, func(s zfsSysctl, v zfsMetricValue) {
+		ch <- c.constSysctlMetric(xuio, 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

@@ -161,3 +161,39 @@ func TestVdevCacheStatsParsing(t *testing.T) {
 		t.Fatal("VdevCacheStats parsing handler was not called for some expected sysctls")
 	}
 }
+
+func TestXuioStatsParsing(t *testing.T) {
+	xuioStatsFile, err := os.Open("fixtures/proc/spl/kstat/zfs/xuio_stats")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer xuioStatsFile.Close()
+
+	c := zfsCollector{}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	handlerCalled := false
+	err = c.parseProcfsFile(xuioStatsFile, "xuio_stats", func(s zfsSysctl, v zfsMetricValue) {
+
+		if s != zfsSysctl("kstat.zfs.misc.xuio_stats.onloan_read_buf") {
+			return
+		}
+
+		handlerCalled = true
+
+		if v != zfsMetricValue(32) {
+			t.Fatalf("Incorrect value parsed from procfs data")
+		}
+
+	})
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !handlerCalled {
+		t.Fatal("XuioStats parsing handler was not called for some expected sysctls")
+	}
+}