open-consul/vendor/github.com/prometheus/procfs/mountstats.go

607 lines
18 KiB
Go

// Copyright 2018 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.
package procfs
// While implementing parsing of /proc/[pid]/mountstats, this blog was used
// heavily as a reference:
// https://utcc.utoronto.ca/~cks/space/blog/linux/NFSMountstatsIndex
//
// Special thanks to Chris Siebenmann for all of his posts explaining the
// various statistics available for NFS.
import (
"bufio"
"fmt"
"io"
"strconv"
"strings"
"time"
)
// Constants shared between multiple functions.
const (
deviceEntryLen = 8
fieldBytesLen = 8
fieldEventsLen = 27
statVersion10 = "1.0"
statVersion11 = "1.1"
fieldTransport10TCPLen = 10
fieldTransport10UDPLen = 7
fieldTransport11TCPLen = 13
fieldTransport11UDPLen = 10
)
// A Mount is a device mount parsed from /proc/[pid]/mountstats.
type Mount struct {
// Name of the device.
Device string
// The mount point of the device.
Mount string
// The filesystem type used by the device.
Type string
// If available additional statistics related to this Mount.
// Use a type assertion to determine if additional statistics are available.
Stats MountStats
}
// A MountStats is a type which contains detailed statistics for a specific
// type of Mount.
type MountStats interface {
mountStats()
}
// A MountStatsNFS is a MountStats implementation for NFSv3 and v4 mounts.
type MountStatsNFS struct {
// The version of statistics provided.
StatVersion string
// The age of the NFS mount.
Age time.Duration
// Statistics related to byte counters for various operations.
Bytes NFSBytesStats
// Statistics related to various NFS event occurrences.
Events NFSEventsStats
// Statistics broken down by filesystem operation.
Operations []NFSOperationStats
// Statistics about the NFS RPC transport.
Transport NFSTransportStats
}
// mountStats implements MountStats.
func (m MountStatsNFS) mountStats() {}
// A NFSBytesStats contains statistics about the number of bytes read and written
// by an NFS client to and from an NFS server.
type NFSBytesStats struct {
// Number of bytes read using the read() syscall.
Read uint64
// Number of bytes written using the write() syscall.
Write uint64
// Number of bytes read using the read() syscall in O_DIRECT mode.
DirectRead uint64
// Number of bytes written using the write() syscall in O_DIRECT mode.
DirectWrite uint64
// Number of bytes read from the NFS server, in total.
ReadTotal uint64
// Number of bytes written to the NFS server, in total.
WriteTotal uint64
// Number of pages read directly via mmap()'d files.
ReadPages uint64
// Number of pages written directly via mmap()'d files.
WritePages uint64
}
// A NFSEventsStats contains statistics about NFS event occurrences.
type NFSEventsStats struct {
// Number of times cached inode attributes are re-validated from the server.
InodeRevalidate uint64
// Number of times cached dentry nodes are re-validated from the server.
DnodeRevalidate uint64
// Number of times an inode cache is cleared.
DataInvalidate uint64
// Number of times cached inode attributes are invalidated.
AttributeInvalidate uint64
// Number of times files or directories have been open()'d.
VFSOpen uint64
// Number of times a directory lookup has occurred.
VFSLookup uint64
// Number of times permissions have been checked.
VFSAccess uint64
// Number of updates (and potential writes) to pages.
VFSUpdatePage uint64
// Number of pages read directly via mmap()'d files.
VFSReadPage uint64
// Number of times a group of pages have been read.
VFSReadPages uint64
// Number of pages written directly via mmap()'d files.
VFSWritePage uint64
// Number of times a group of pages have been written.
VFSWritePages uint64
// Number of times directory entries have been read with getdents().
VFSGetdents uint64
// Number of times attributes have been set on inodes.
VFSSetattr uint64
// Number of pending writes that have been forcefully flushed to the server.
VFSFlush uint64
// Number of times fsync() has been called on directories and files.
VFSFsync uint64
// Number of times locking has been attempted on a file.
VFSLock uint64
// Number of times files have been closed and released.
VFSFileRelease uint64
// Unknown. Possibly unused.
CongestionWait uint64
// Number of times files have been truncated.
Truncation uint64
// Number of times a file has been grown due to writes beyond its existing end.
WriteExtension uint64
// Number of times a file was removed while still open by another process.
SillyRename uint64
// Number of times the NFS server gave less data than expected while reading.
ShortRead uint64
// Number of times the NFS server wrote less data than expected while writing.
ShortWrite uint64
// Number of times the NFS server indicated EJUKEBOX; retrieving data from
// offline storage.
JukeboxDelay uint64
// Number of NFS v4.1+ pNFS reads.
PNFSRead uint64
// Number of NFS v4.1+ pNFS writes.
PNFSWrite uint64
}
// A NFSOperationStats contains statistics for a single operation.
type NFSOperationStats struct {
// The name of the operation.
Operation string
// Number of requests performed for this operation.
Requests uint64
// Number of times an actual RPC request has been transmitted for this operation.
Transmissions uint64
// Number of times a request has had a major timeout.
MajorTimeouts uint64
// Number of bytes sent for this operation, including RPC headers and payload.
BytesSent uint64
// Number of bytes received for this operation, including RPC headers and payload.
BytesReceived uint64
// Duration all requests spent queued for transmission before they were sent.
CumulativeQueueTime time.Duration
// Duration it took to get a reply back after the request was transmitted.
CumulativeTotalResponseTime time.Duration
// Duration from when a request was enqueued to when it was completely handled.
CumulativeTotalRequestTime time.Duration
}
// A NFSTransportStats contains statistics for the NFS mount RPC requests and
// responses.
type NFSTransportStats struct {
// The transport protocol used for the NFS mount.
Protocol string
// The local port used for the NFS mount.
Port uint64
// Number of times the client has had to establish a connection from scratch
// to the NFS server.
Bind uint64
// Number of times the client has made a TCP connection to the NFS server.
Connect uint64
// Duration (in jiffies, a kernel internal unit of time) the NFS mount has
// spent waiting for connections to the server to be established.
ConnectIdleTime uint64
// Duration since the NFS mount last saw any RPC traffic.
IdleTime time.Duration
// Number of RPC requests for this mount sent to the NFS server.
Sends uint64
// Number of RPC responses for this mount received from the NFS server.
Receives uint64
// Number of times the NFS server sent a response with a transaction ID
// unknown to this client.
BadTransactionIDs uint64
// A running counter, incremented on each request as the current difference
// ebetween sends and receives.
CumulativeActiveRequests uint64
// A running counter, incremented on each request by the current backlog
// queue size.
CumulativeBacklog uint64
// Stats below only available with stat version 1.1.
// Maximum number of simultaneously active RPC requests ever used.
MaximumRPCSlotsUsed uint64
// A running counter, incremented on each request as the current size of the
// sending queue.
CumulativeSendingQueue uint64
// A running counter, incremented on each request as the current size of the
// pending queue.
CumulativePendingQueue uint64
}
// parseMountStats parses a /proc/[pid]/mountstats file and returns a slice
// of Mount structures containing detailed information about each mount.
// If available, statistics for each mount are parsed as well.
func parseMountStats(r io.Reader) ([]*Mount, error) {
const (
device = "device"
statVersionPrefix = "statvers="
nfs3Type = "nfs"
nfs4Type = "nfs4"
)
var mounts []*Mount
s := bufio.NewScanner(r)
for s.Scan() {
// Only look for device entries in this function
ss := strings.Fields(string(s.Bytes()))
if len(ss) == 0 || ss[0] != device {
continue
}
m, err := parseMount(ss)
if err != nil {
return nil, err
}
// Does this mount also possess statistics information?
if len(ss) > deviceEntryLen {
// Only NFSv3 and v4 are supported for parsing statistics
if m.Type != nfs3Type && m.Type != nfs4Type {
return nil, fmt.Errorf("cannot parse MountStats for fstype %q", m.Type)
}
statVersion := strings.TrimPrefix(ss[8], statVersionPrefix)
stats, err := parseMountStatsNFS(s, statVersion)
if err != nil {
return nil, err
}
m.Stats = stats
}
mounts = append(mounts, m)
}
return mounts, s.Err()
}
// parseMount parses an entry in /proc/[pid]/mountstats in the format:
// device [device] mounted on [mount] with fstype [type]
func parseMount(ss []string) (*Mount, error) {
if len(ss) < deviceEntryLen {
return nil, fmt.Errorf("invalid device entry: %v", ss)
}
// Check for specific words appearing at specific indices to ensure
// the format is consistent with what we expect
format := []struct {
i int
s string
}{
{i: 0, s: "device"},
{i: 2, s: "mounted"},
{i: 3, s: "on"},
{i: 5, s: "with"},
{i: 6, s: "fstype"},
}
for _, f := range format {
if ss[f.i] != f.s {
return nil, fmt.Errorf("invalid device entry: %v", ss)
}
}
return &Mount{
Device: ss[1],
Mount: ss[4],
Type: ss[7],
}, nil
}
// parseMountStatsNFS parses a MountStatsNFS by scanning additional information
// related to NFS statistics.
func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, error) {
// Field indicators for parsing specific types of data
const (
fieldAge = "age:"
fieldBytes = "bytes:"
fieldEvents = "events:"
fieldPerOpStats = "per-op"
fieldTransport = "xprt:"
)
stats := &MountStatsNFS{
StatVersion: statVersion,
}
for s.Scan() {
ss := strings.Fields(string(s.Bytes()))
if len(ss) == 0 {
break
}
if len(ss) < 2 {
return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
}
switch ss[0] {
case fieldAge:
// Age integer is in seconds
d, err := time.ParseDuration(ss[1] + "s")
if err != nil {
return nil, err
}
stats.Age = d
case fieldBytes:
bstats, err := parseNFSBytesStats(ss[1:])
if err != nil {
return nil, err
}
stats.Bytes = *bstats
case fieldEvents:
estats, err := parseNFSEventsStats(ss[1:])
if err != nil {
return nil, err
}
stats.Events = *estats
case fieldTransport:
if len(ss) < 3 {
return nil, fmt.Errorf("not enough information for NFS transport stats: %v", ss)
}
tstats, err := parseNFSTransportStats(ss[1:], statVersion)
if err != nil {
return nil, err
}
stats.Transport = *tstats
}
// When encountering "per-operation statistics", we must break this
// loop and parse them separately to ensure we can terminate parsing
// before reaching another device entry; hence why this 'if' statement
// is not just another switch case
if ss[0] == fieldPerOpStats {
break
}
}
if err := s.Err(); err != nil {
return nil, err
}
// NFS per-operation stats appear last before the next device entry
perOpStats, err := parseNFSOperationStats(s)
if err != nil {
return nil, err
}
stats.Operations = perOpStats
return stats, nil
}
// parseNFSBytesStats parses a NFSBytesStats line using an input set of
// integer fields.
func parseNFSBytesStats(ss []string) (*NFSBytesStats, error) {
if len(ss) != fieldBytesLen {
return nil, fmt.Errorf("invalid NFS bytes stats: %v", ss)
}
ns := make([]uint64, 0, fieldBytesLen)
for _, s := range ss {
n, err := strconv.ParseUint(s, 10, 64)
if err != nil {
return nil, err
}
ns = append(ns, n)
}
return &NFSBytesStats{
Read: ns[0],
Write: ns[1],
DirectRead: ns[2],
DirectWrite: ns[3],
ReadTotal: ns[4],
WriteTotal: ns[5],
ReadPages: ns[6],
WritePages: ns[7],
}, nil
}
// parseNFSEventsStats parses a NFSEventsStats line using an input set of
// integer fields.
func parseNFSEventsStats(ss []string) (*NFSEventsStats, error) {
if len(ss) != fieldEventsLen {
return nil, fmt.Errorf("invalid NFS events stats: %v", ss)
}
ns := make([]uint64, 0, fieldEventsLen)
for _, s := range ss {
n, err := strconv.ParseUint(s, 10, 64)
if err != nil {
return nil, err
}
ns = append(ns, n)
}
return &NFSEventsStats{
InodeRevalidate: ns[0],
DnodeRevalidate: ns[1],
DataInvalidate: ns[2],
AttributeInvalidate: ns[3],
VFSOpen: ns[4],
VFSLookup: ns[5],
VFSAccess: ns[6],
VFSUpdatePage: ns[7],
VFSReadPage: ns[8],
VFSReadPages: ns[9],
VFSWritePage: ns[10],
VFSWritePages: ns[11],
VFSGetdents: ns[12],
VFSSetattr: ns[13],
VFSFlush: ns[14],
VFSFsync: ns[15],
VFSLock: ns[16],
VFSFileRelease: ns[17],
CongestionWait: ns[18],
Truncation: ns[19],
WriteExtension: ns[20],
SillyRename: ns[21],
ShortRead: ns[22],
ShortWrite: ns[23],
JukeboxDelay: ns[24],
PNFSRead: ns[25],
PNFSWrite: ns[26],
}, nil
}
// parseNFSOperationStats parses a slice of NFSOperationStats by scanning
// additional information about per-operation statistics until an empty
// line is reached.
func parseNFSOperationStats(s *bufio.Scanner) ([]NFSOperationStats, error) {
const (
// Number of expected fields in each per-operation statistics set
numFields = 9
)
var ops []NFSOperationStats
for s.Scan() {
ss := strings.Fields(string(s.Bytes()))
if len(ss) == 0 {
// Must break when reading a blank line after per-operation stats to
// enable top-level function to parse the next device entry
break
}
if len(ss) != numFields {
return nil, fmt.Errorf("invalid NFS per-operations stats: %v", ss)
}
// Skip string operation name for integers
ns := make([]uint64, 0, numFields-1)
for _, st := range ss[1:] {
n, err := strconv.ParseUint(st, 10, 64)
if err != nil {
return nil, err
}
ns = append(ns, n)
}
ops = append(ops, NFSOperationStats{
Operation: strings.TrimSuffix(ss[0], ":"),
Requests: ns[0],
Transmissions: ns[1],
MajorTimeouts: ns[2],
BytesSent: ns[3],
BytesReceived: ns[4],
CumulativeQueueTime: time.Duration(ns[5]) * time.Millisecond,
CumulativeTotalResponseTime: time.Duration(ns[6]) * time.Millisecond,
CumulativeTotalRequestTime: time.Duration(ns[7]) * time.Millisecond,
})
}
return ops, s.Err()
}
// parseNFSTransportStats parses a NFSTransportStats line using an input set of
// integer fields matched to a specific stats version.
func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats, error) {
// Extract the protocol field. It is the only string value in the line
protocol := ss[0]
ss = ss[1:]
switch statVersion {
case statVersion10:
var expectedLength int
if protocol == "tcp" {
expectedLength = fieldTransport10TCPLen
} else if protocol == "udp" {
expectedLength = fieldTransport10UDPLen
} else {
return nil, fmt.Errorf("invalid NFS protocol \"%s\" in stats 1.0 statement: %v", protocol, ss)
}
if len(ss) != expectedLength {
return nil, fmt.Errorf("invalid NFS transport stats 1.0 statement: %v", ss)
}
case statVersion11:
var expectedLength int
if protocol == "tcp" {
expectedLength = fieldTransport11TCPLen
} else if protocol == "udp" {
expectedLength = fieldTransport11UDPLen
} else {
return nil, fmt.Errorf("invalid NFS protocol \"%s\" in stats 1.1 statement: %v", protocol, ss)
}
if len(ss) != expectedLength {
return nil, fmt.Errorf("invalid NFS transport stats 1.1 statement: %v", ss)
}
default:
return nil, fmt.Errorf("unrecognized NFS transport stats version: %q", statVersion)
}
// Allocate enough for v1.1 stats since zero value for v1.1 stats will be okay
// in a v1.0 response. Since the stat length is bigger for TCP stats, we use
// the TCP length here.
//
// Note: slice length must be set to length of v1.1 stats to avoid a panic when
// only v1.0 stats are present.
// See: https://github.com/prometheus/node_exporter/issues/571.
ns := make([]uint64, fieldTransport11TCPLen)
for i, s := range ss {
n, err := strconv.ParseUint(s, 10, 64)
if err != nil {
return nil, err
}
ns[i] = n
}
// The fields differ depending on the transport protocol (TCP or UDP)
// From https://utcc.utoronto.ca/%7Ecks/space/blog/linux/NFSMountstatsXprt
//
// For the udp RPC transport there is no connection count, connect idle time,
// or idle time (fields #3, #4, and #5); all other fields are the same. So
// we set them to 0 here.
if protocol == "udp" {
ns = append(ns[:2], append(make([]uint64, 3), ns[2:]...)...)
}
return &NFSTransportStats{
Protocol: protocol,
Port: ns[0],
Bind: ns[1],
Connect: ns[2],
ConnectIdleTime: ns[3],
IdleTime: time.Duration(ns[4]) * time.Second,
Sends: ns[5],
Receives: ns[6],
BadTransactionIDs: ns[7],
CumulativeActiveRequests: ns[8],
CumulativeBacklog: ns[9],
MaximumRPCSlotsUsed: ns[10],
CumulativeSendingQueue: ns[11],
CumulativePendingQueue: ns[12],
}, nil
}