NFS I/O Stats Collector (#91)

* Initial version

* Delete values for vanished mount points and  comments

collectors/nfsiostatMetric.go

@@ -0,0 +1,166 @@
+package collectors
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	cclog "github.com/ClusterCockpit/cc-metric-collector/pkg/ccLogger"
+	lp "github.com/ClusterCockpit/cc-metric-collector/pkg/ccMetric"
+)
+
+// These are the fields we read from the JSON configuration
+type NfsIOStatCollectorConfig struct {
+	ExcludeMetrics          []string `json:"exclude_metrics,omitempty"`
+	ExcludeFilesystem       []string `json:"exclude_filesystem,omitempty"`
+	UseServerAddressAsSType bool     `json:"use_server_as_stype,omitempty"`
+}
+
+// This contains all variables we need during execution and the variables
+// defined by metricCollector (name, init, ...)
+type NfsIOStatCollector struct {
+	metricCollector
+	config NfsIOStatCollectorConfig    // the configuration structure
+	meta   map[string]string           // default meta information
+	tags   map[string]string           // default tags
+	data   map[string]map[string]int64 // data storage for difference calculation
+	key    string                      // which device info should be used as subtype ID? 'server' or 'mntpoint', see NfsIOStatCollectorConfig.UseServerAddressAsSType
+}
+
+var deviceRegex = regexp.MustCompile(`device (?P<server>[^ ]+) mounted on (?P<mntpoint>[^ ]+) with fstype nfs(?P<version>\d*) statvers=[\d\.]+`)
+var bytesRegex = regexp.MustCompile(`\s+bytes:\s+(?P<nread>[^ ]+) (?P<nwrite>[^ ]+) (?P<dread>[^ ]+) (?P<dwrite>[^ ]+) (?P<nfsread>[^ ]+) (?P<nfswrite>[^ ]+) (?P<pageread>[^ ]+) (?P<pagewrite>[^ ]+)`)
+
+func resolve_regex_fields(s string, regex *regexp.Regexp) map[string]string {
+	fields := make(map[string]string)
+	groups := regex.SubexpNames()
+	for _, match := range regex.FindAllStringSubmatch(s, -1) {
+		for groupIdx, group := range match {
+			if len(groups[groupIdx]) > 0 {
+				fields[groups[groupIdx]] = group
+			}
+		}
+	}
+	return fields
+}
+
+func (m *NfsIOStatCollector) readNfsiostats() map[string]map[string]int64 {
+	data := make(map[string]map[string]int64)
+	filename := "/proc/self/mountstats"
+	stats, err := os.ReadFile(filename)
+	if err != nil {
+		return data
+	}
+
+	lines := strings.Split(string(stats), "\n")
+	var current map[string]string = nil
+	for _, l := range lines {
+		// Is this a device line with mount point, remote target and NFS version?
+		dev := resolve_regex_fields(l, deviceRegex)
+		if len(dev) > 0 {
+			if _, ok := stringArrayContains(m.config.ExcludeFilesystem, dev[m.key]); !ok {
+				current = dev
+				if len(current["version"]) == 0 {
+					current["version"] = "3"
+				}
+			}
+		}
+
+		if len(current) > 0 {
+			// Byte line parsing (if found the device for it)
+			bytes := resolve_regex_fields(l, bytesRegex)
+			if len(bytes) > 0 {
+				data[current[m.key]] = make(map[string]int64)
+				for name, sval := range bytes {
+					if _, ok := stringArrayContains(m.config.ExcludeMetrics, name); !ok {
+						val, err := strconv.ParseInt(sval, 10, 64)
+						if err == nil {
+							data[current[m.key]][name] = val
+						}
+					}
+
+				}
+				current = nil
+			}
+		}
+	}
+	return data
+}
+
+func (m *NfsIOStatCollector) Init(config json.RawMessage) error {
+	var err error = nil
+	m.name = "NfsIOStatCollector"
+	m.setup()
+	m.parallel = true
+	m.meta = map[string]string{"source": m.name, "group": "NFS", "unit": "bytes"}
+	m.tags = map[string]string{"type": "node"}
+	m.config.UseServerAddressAsSType = false
+	if len(config) > 0 {
+		err = json.Unmarshal(config, &m.config)
+		if err != nil {
+			cclog.ComponentError(m.name, "Error reading config:", err.Error())
+			return err
+		}
+	}
+	m.key = "mntpoint"
+	if m.config.UseServerAddressAsSType {
+		m.key = "server"
+	}
+	m.data = m.readNfsiostats()
+	m.init = true
+	return err
+}
+
+func (m *NfsIOStatCollector) Read(interval time.Duration, output chan lp.CCMetric) {
+	timestamp := time.Now()
+
+	// Get the current values for all mountpoints
+	newdata := m.readNfsiostats()
+
+	for mntpoint, values := range newdata {
+		// Was the mount point already present in the last iteration
+		if old, ok := m.data[mntpoint]; ok {
+			// Calculate the difference of old and new values
+			for i := range values {
+				x := values[i] - old[i]
+				y, err := lp.New(fmt.Sprintf("nfsio_%s", i), m.tags, m.meta, map[string]interface{}{"value": x}, timestamp)
+				if err == nil {
+					if strings.HasPrefix(i, "page") {
+						y.AddMeta("unit", "4K_Pages")
+					}
+					y.AddTag("stype", "filesystem")
+					y.AddTag("stype-id", mntpoint)
+					// Send it to output channel
+					output <- y
+				}
+				// Update old to the new value for the next iteration
+				old[i] = values[i]
+			}
+		} else {
+			// First time we see this mount point, store all values
+			m.data[mntpoint] = values
+		}
+	}
+	// Reset entries that do not exist anymore
+	for mntpoint := range m.data {
+		found := false
+		for new := range newdata {
+			if new == mntpoint {
+				found = true
+				break
+			}
+		}
+		if !found {
+			m.data[mntpoint] = nil
+		}
+	}
+
+}
+
+func (m *NfsIOStatCollector) Close() {
+	// Unset flag
+	m.init = false
+}

collectors/nfsiostatMetric.md

@@ -0,0 +1,27 @@
+## `nfsiostat` collector
+
+```json
+  "nfsiostat": {
+    "exclude_metrics": [
+      "nfsio_oread"
+    ],
+    "exclude_filesystems" : [
+        "/mnt",
+    ],
+    "use_server_as_stype": false
+  }
+```
+
+The `nfsiostat` collector reads data from `/proc/self/mountstats` and outputs a handful **node** metrics for each NFS filesystem. If a metric or filesystem is not required, it can be excluded from forwarding it to the sink.
+
+Metrics:
+* `nfsio_nread`: Bytes transferred by normal `read()` calls
+* `nfsio_nwrite`: Bytes transferred by normal `write()` calls
+* `nfsio_oread`: Bytes transferred by `read()` calls with `O_DIRECT`
+* `nfsio_owrite`: Bytes transferred by `write()` calls with `O_DIRECT`
+* `nfsio_pageread`: Pages transferred by `read()` calls
+* `nfsio_pagewrite`: Pages transferred by `write()` calls
+* `nfsio_nfsread`: Bytes transferred for reading from the server
+* `nfsio_nfswrite`: Pages transferred by writing to the server
+
+The `nfsiostat` collector adds the mountpoint to the tags as `stype=filesystem,stype-id=<mountpoint>`. If the server address should be used instead of the mountpoint, use the `use_server_as_stype` config setting.