ZFS Collector: Add zfetchstats functionality

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

1 files changed, 24 insertions, 10 deletions

diff --git a/collector/zfs_linux.go b/collector/zfs_linux.go
index 17cfcae..02404a4 100644
--- a/collector/zfs_linux.go
+++ b/collector/zfs_linux.go
@@ -15,10 +15,10 @@ package collector
 
 import (
         "bufio"
-        "errors"
         "fmt"
         "io"
         "os"
+        "path/filepath"
         "strconv"
         "strings"
 
@@ -27,31 +27,45 @@ import (
 )
 
 const (
-        zfsArcstatsProcpath = "spl/kstat/zfs/arcstats"
+        zfsProcpathBase  = "spl/kstat/zfs/"
+        zfsArcstatsExt   = "arcstats"
+        zfsFetchstatsExt = "zfetchstats"
 )
 
-func (c *zfsCollector) openArcstatsFile() (file *os.File, err error) {
-        file, err = os.Open(procFilePath(zfsArcstatsProcpath))
+func (c *zfsCollector) openProcFile(path string) (file *os.File, err error) {
+        file, err = os.Open(procFilePath(path))
         if err != nil {
-                log.Debugf("Cannot open %q for reading. Is the kernel module loaded?", procFilePath(zfsArcstatsProcpath))
+                log.Debugf("Cannot open %q for reading. Is the kernel module loaded?", procFilePath(path))
                 err = zfsNotAvailableError
         }
         return
 }
 
 func (c *zfsCollector) updateArcstats(ch chan<- prometheus.Metric) (err error) {
-        file, err := c.openArcstatsFile()
+        file, err := c.openProcFile(filepath.Join(zfsProcpathBase, zfsArcstatsExt))
         if err != nil {
                 return err
         }
         defer file.Close()
 
-        return c.parseArcstatsProcfsFile(file, func(s zfsSysctl, v zfsMetricValue) {
+        return c.parseProcfsFile(file, zfsArcstatsExt, func(s zfsSysctl, v zfsMetricValue) {
                 ch <- c.constSysctlMetric(arc, s, v)
         })
 }
 
-func (c *zfsCollector) parseArcstatsProcfsFile(reader io.Reader, handler func(zfsSysctl, zfsMetricValue)) (err error) {
+func (c *zfsCollector) updateZfetchstats(ch chan<- prometheus.Metric) (err error) {
+        file, err := c.openProcFile(filepath.Join(zfsProcpathBase, zfsFetchstatsExt))
+        if err != nil {
+                return err
+        }
+        defer file.Close()
+
+        return c.parseProcfsFile(file, zfsFetchstatsExt, func(s zfsSysctl, v zfsMetricValue) {
+                ch <- c.constSysctlMetric(zfetch, s, v)
+        })
+}
+
+func (c *zfsCollector) parseProcfsFile(reader io.Reader, fmt_ext string, handler func(zfsSysctl, zfsMetricValue)) (err error) {
         scanner := bufio.NewScanner(reader)
 
         parseLine := false
@@ -69,7 +83,7 @@ func (c *zfsCollector) parseArcstatsProcfsFile(reader io.Reader, handler func(zf
                         continue
                 }
 
-                key := fmt.Sprintf("kstat.zfs.misc.arcstats.%s", parts[0])
+                key := fmt.Sprintf("kstat.zfs.misc.%s.%s", fmt_ext, parts[0])
 
                 value, err := strconv.Atoi(parts[2])
                 if err != nil {
@@ -79,7 +93,7 @@ func (c *zfsCollector) parseArcstatsProcfsFile(reader io.Reader, handler func(zf
 
         }
         if !parseLine {
-                return errors.New("did not parse a single arcstat metric")
+                return fmt.Errorf("did not parse a single %q metric", fmt_ext)
         }
 
         return scanner.Err()