khenaidoo | ffe076b | 2019-01-15 16:08:08 -0500 | [diff] [blame^] | 1 | // Copyright 2015 The Prometheus Authors |
| 2 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 3 | // you may not use this file except in compliance with the License. |
| 4 | // You may obtain a copy of the License at |
| 5 | // |
| 6 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 7 | // |
| 8 | // Unless required by applicable law or agreed to in writing, software |
| 9 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 10 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 11 | // See the License for the specific language governing permissions and |
| 12 | // limitations under the License. |
| 13 | |
| 14 | package prometheus |
| 15 | |
| 16 | import ( |
| 17 | "errors" |
| 18 | "os" |
| 19 | |
| 20 | "github.com/prometheus/procfs" |
| 21 | ) |
| 22 | |
| 23 | type processCollector struct { |
| 24 | collectFn func(chan<- Metric) |
| 25 | pidFn func() (int, error) |
| 26 | reportErrors bool |
| 27 | cpuTotal *Desc |
| 28 | openFDs, maxFDs *Desc |
| 29 | vsize, maxVsize *Desc |
| 30 | rss *Desc |
| 31 | startTime *Desc |
| 32 | } |
| 33 | |
| 34 | // ProcessCollectorOpts defines the behavior of a process metrics collector |
| 35 | // created with NewProcessCollector. |
| 36 | type ProcessCollectorOpts struct { |
| 37 | // PidFn returns the PID of the process the collector collects metrics |
| 38 | // for. It is called upon each collection. By default, the PID of the |
| 39 | // current process is used, as determined on construction time by |
| 40 | // calling os.Getpid(). |
| 41 | PidFn func() (int, error) |
| 42 | // If non-empty, each of the collected metrics is prefixed by the |
| 43 | // provided string and an underscore ("_"). |
| 44 | Namespace string |
| 45 | // If true, any error encountered during collection is reported as an |
| 46 | // invalid metric (see NewInvalidMetric). Otherwise, errors are ignored |
| 47 | // and the collected metrics will be incomplete. (Possibly, no metrics |
| 48 | // will be collected at all.) While that's usually not desired, it is |
| 49 | // appropriate for the common "mix-in" of process metrics, where process |
| 50 | // metrics are nice to have, but failing to collect them should not |
| 51 | // disrupt the collection of the remaining metrics. |
| 52 | ReportErrors bool |
| 53 | } |
| 54 | |
| 55 | // NewProcessCollector returns a collector which exports the current state of |
| 56 | // process metrics including CPU, memory and file descriptor usage as well as |
| 57 | // the process start time. The detailed behavior is defined by the provided |
| 58 | // ProcessCollectorOpts. The zero value of ProcessCollectorOpts creates a |
| 59 | // collector for the current process with an empty namespace string and no error |
| 60 | // reporting. |
| 61 | // |
| 62 | // Currently, the collector depends on a Linux-style proc filesystem and |
| 63 | // therefore only exports metrics for Linux. |
| 64 | // |
| 65 | // Note: An older version of this function had the following signature: |
| 66 | // |
| 67 | // NewProcessCollector(pid int, namespace string) Collector |
| 68 | // |
| 69 | // Most commonly, it was called as |
| 70 | // |
| 71 | // NewProcessCollector(os.Getpid(), "") |
| 72 | // |
| 73 | // The following call of the current version is equivalent to the above: |
| 74 | // |
| 75 | // NewProcessCollector(ProcessCollectorOpts{}) |
| 76 | func NewProcessCollector(opts ProcessCollectorOpts) Collector { |
| 77 | ns := "" |
| 78 | if len(opts.Namespace) > 0 { |
| 79 | ns = opts.Namespace + "_" |
| 80 | } |
| 81 | |
| 82 | c := &processCollector{ |
| 83 | reportErrors: opts.ReportErrors, |
| 84 | cpuTotal: NewDesc( |
| 85 | ns+"process_cpu_seconds_total", |
| 86 | "Total user and system CPU time spent in seconds.", |
| 87 | nil, nil, |
| 88 | ), |
| 89 | openFDs: NewDesc( |
| 90 | ns+"process_open_fds", |
| 91 | "Number of open file descriptors.", |
| 92 | nil, nil, |
| 93 | ), |
| 94 | maxFDs: NewDesc( |
| 95 | ns+"process_max_fds", |
| 96 | "Maximum number of open file descriptors.", |
| 97 | nil, nil, |
| 98 | ), |
| 99 | vsize: NewDesc( |
| 100 | ns+"process_virtual_memory_bytes", |
| 101 | "Virtual memory size in bytes.", |
| 102 | nil, nil, |
| 103 | ), |
| 104 | maxVsize: NewDesc( |
| 105 | ns+"process_virtual_memory_max_bytes", |
| 106 | "Maximum amount of virtual memory available in bytes.", |
| 107 | nil, nil, |
| 108 | ), |
| 109 | rss: NewDesc( |
| 110 | ns+"process_resident_memory_bytes", |
| 111 | "Resident memory size in bytes.", |
| 112 | nil, nil, |
| 113 | ), |
| 114 | startTime: NewDesc( |
| 115 | ns+"process_start_time_seconds", |
| 116 | "Start time of the process since unix epoch in seconds.", |
| 117 | nil, nil, |
| 118 | ), |
| 119 | } |
| 120 | |
| 121 | if opts.PidFn == nil { |
| 122 | pid := os.Getpid() |
| 123 | c.pidFn = func() (int, error) { return pid, nil } |
| 124 | } else { |
| 125 | c.pidFn = opts.PidFn |
| 126 | } |
| 127 | |
| 128 | // Set up process metric collection if supported by the runtime. |
| 129 | if _, err := procfs.NewStat(); err == nil { |
| 130 | c.collectFn = c.processCollect |
| 131 | } else { |
| 132 | c.collectFn = func(ch chan<- Metric) { |
| 133 | c.reportError(ch, nil, errors.New("process metrics not supported on this platform")) |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | return c |
| 138 | } |
| 139 | |
| 140 | // Describe returns all descriptions of the collector. |
| 141 | func (c *processCollector) Describe(ch chan<- *Desc) { |
| 142 | ch <- c.cpuTotal |
| 143 | ch <- c.openFDs |
| 144 | ch <- c.maxFDs |
| 145 | ch <- c.vsize |
| 146 | ch <- c.maxVsize |
| 147 | ch <- c.rss |
| 148 | ch <- c.startTime |
| 149 | } |
| 150 | |
| 151 | // Collect returns the current state of all metrics of the collector. |
| 152 | func (c *processCollector) Collect(ch chan<- Metric) { |
| 153 | c.collectFn(ch) |
| 154 | } |
| 155 | |
| 156 | func (c *processCollector) processCollect(ch chan<- Metric) { |
| 157 | pid, err := c.pidFn() |
| 158 | if err != nil { |
| 159 | c.reportError(ch, nil, err) |
| 160 | return |
| 161 | } |
| 162 | |
| 163 | p, err := procfs.NewProc(pid) |
| 164 | if err != nil { |
| 165 | c.reportError(ch, nil, err) |
| 166 | return |
| 167 | } |
| 168 | |
| 169 | if stat, err := p.NewStat(); err == nil { |
| 170 | ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime()) |
| 171 | ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory())) |
| 172 | ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory())) |
| 173 | if startTime, err := stat.StartTime(); err == nil { |
| 174 | ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime) |
| 175 | } else { |
| 176 | c.reportError(ch, c.startTime, err) |
| 177 | } |
| 178 | } else { |
| 179 | c.reportError(ch, nil, err) |
| 180 | } |
| 181 | |
| 182 | if fds, err := p.FileDescriptorsLen(); err == nil { |
| 183 | ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds)) |
| 184 | } else { |
| 185 | c.reportError(ch, c.openFDs, err) |
| 186 | } |
| 187 | |
| 188 | if limits, err := p.NewLimits(); err == nil { |
| 189 | ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles)) |
| 190 | ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace)) |
| 191 | } else { |
| 192 | c.reportError(ch, nil, err) |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) { |
| 197 | if !c.reportErrors { |
| 198 | return |
| 199 | } |
| 200 | if desc == nil { |
| 201 | desc = NewInvalidDesc(err) |
| 202 | } |
| 203 | ch <- NewInvalidMetric(desc, err) |
| 204 | } |