Add Linux SAS metrics

This adds metrics for SAS (Serial-Attached SCSI) devices.

Issue prometheus#2386

collector/sas_linux.go

@@ -0,0 +1,215 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !nocpu
+// +build !nocpu
+
+package collector
+
+// Exported metrics, from /sys/class/sas_phy/<name>/*:
+//
+// - invalid_dword_count
+// - loss_of_dword_sync_count
+// - negotiated_linkrate
+// - phy_reset_problem_count
+// - running_disparity_error_count
+//
+// Four of these are counters, one is a gauge.
+
+import (
+	"fmt"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs/sysfs"
+)
+
+type sasCollector struct {
+	fs sysfs.FS
+
+	sasInvalidDword          *prometheus.Desc
+	sasLossOfDwordSync       *prometheus.Desc
+	sasNegotiatedLinkrate    *prometheus.Desc
+	sasPhyResetProblem       *prometheus.Desc
+	sasRunningDisparityError *prometheus.Desc
+
+	logger log.Logger
+}
+
+const sasCollectorSubsystem = "sas"
+
+func init() {
+	registerCollector("sas", defaultEnabled, NewSASCollector)
+}
+
+// NewSASCollector returns a new Collector exposing SAS storage statistics.
+func NewSASCollector(logger log.Logger) (Collector, error) {
+	fs, err := sysfs.NewFS(*sysPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open procfs: %w", err)
+	}
+	c := &sasCollector{
+		fs: fs,
+		sasInvalidDword: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, sasCollectorSubsystem, "phy_invalid_dword"),
+			"SAS PHY count of invalid dwords.",
+			[]string{"phy", "port", "host", "expander", "block_device", "sas_address"}, nil,
+		),
+		sasLossOfDwordSync: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, sasCollectorSubsystem, "phy_loss_of_dword_sync"),
+			"SAS PHY count of lost dword sync.",
+			[]string{"phy", "port", "host", "expander", "block_device", "sas_address"}, nil,
+		),
+		sasNegotiatedLinkrate: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, sasCollectorSubsystem, "phy_negotiated_linkrate"),
+			"SAS PHY negotiated link rate in Gbps.",
+			[]string{"phy", "port", "host", "expander", "block_device", "sas_address"}, nil,
+		),
+		sasPhyResetProblem: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, sasCollectorSubsystem, "phy_reset_problem"),
+			"SAS PHY count of reset problems.",
+			[]string{"phy", "port", "host", "expander", "block_device", "sas_address"}, nil,
+		),
+		sasRunningDisparityError: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, sasCollectorSubsystem, "phy_running_disparity_error"),
+			"SAS PHY count of running disparity errors.",
+			[]string{"phy", "port", "host", "expander", "block_device", "sas_address"}, nil,
+		),
+		logger: logger,
+	}
+
+	return c, nil
+}
+
+// Update implements Collector and exposes cpu related metrics from /proc/stat and /sys/.../cpu/.
+func (s *sasCollector) Update(ch chan<- prometheus.Metric) error {
+	sasEndDevices, err := s.fs.SASEndDeviceClass()
+	if err != nil {
+		return err
+	}
+
+	sasExpanders, err := s.fs.SASExpanderClass()
+	if err != nil {
+		return err
+	}
+
+	sasHosts, err := s.fs.SASHostClass()
+	if err != nil {
+		return err
+	}
+
+	sasPhys, err := s.fs.SASPhyClass()
+	if err != nil {
+		return err
+	}
+
+	sasPorts, err := s.fs.SASPortClass()
+	if err != nil {
+		return err
+	}
+
+	for _, phy := range sasPhys {
+		// One per SAS link in the system.
+		phyName := phy.Name
+		portName := phy.SASPort
+		sasAddress := phy.SASAddress
+		hostName := ""
+		expanderName := ""
+		blockDeviceName := ""
+
+		// Check to see if this Phy is connected directly to a SAS host (~controller card)
+		host := sasHosts.GetByPhy(phyName)
+		if host != nil {
+			hostName = host.Name
+		}
+
+		expander := sasExpanders.GetByPhy(phyName)
+		if expander != nil {
+			expanderName = expander.Name
+
+			// If we didn't find a host name before, then maybe it's connected
+			// host -> expander -> Phy.  So try checking the expander's Ports?
+			// TODO: Do this recursively for nested expanders.
+			if hostName == "" {
+				port := sasPorts.GetByExpander(expanderName)
+				if port != nil {
+					host := sasHosts.GetByPort(port.Name)
+					if host != nil {
+						hostName = host.Name
+					}
+				}
+			}
+
+		}
+
+		// This is the best mapping that I've found for phy->blockDevice.  Yes, it's horrible.
+		port := sasPorts.GetByName(portName)
+		if port != nil {
+			for _, portEndDevice := range port.EndDevices {
+				endDevice := sasEndDevices.GetByName(portEndDevice)
+				if endDevice != nil {
+					if len(endDevice.BlockDevices) > 0 {
+						blockDeviceName = endDevice.BlockDevices[0]
+					}
+				}
+			}
+		}
+
+		ch <- prometheus.MustNewConstMetric(s.sasInvalidDword,
+			prometheus.CounterValue,
+			float64(phy.InvalidDwordCount),
+			phyName,
+			portName,
+			hostName,
+			expanderName,
+			blockDeviceName,
+			sasAddress)
+		ch <- prometheus.MustNewConstMetric(s.sasLossOfDwordSync,
+			prometheus.CounterValue,
+			float64(phy.LossOfDwordSyncCount),
+			phyName,
+			portName,
+			hostName,
+			expanderName,
+			blockDeviceName,
+			sasAddress)
+		ch <- prometheus.MustNewConstMetric(s.sasNegotiatedLinkrate,
+			prometheus.GaugeValue,
+			float64(phy.NegotiatedLinkrate),
+			phyName,
+			portName,
+			hostName,
+			expanderName,
+			blockDeviceName,
+			sasAddress)
+		ch <- prometheus.MustNewConstMetric(s.sasPhyResetProblem,
+			prometheus.CounterValue,
+			float64(phy.PhyResetProblemCount),
+			phyName,
+			portName,
+			hostName,
+			expanderName,
+			blockDeviceName,
+			sasAddress)
+		ch <- prometheus.MustNewConstMetric(s.sasRunningDisparityError,
+			prometheus.CounterValue,
+			float64(phy.RunningDisparityErrorCount),
+			phyName,
+			portName,
+			hostName,
+			expanderName,
+			blockDeviceName,
+			sasAddress)
+	}
+	return nil
+}