/usr/share/gocode/src/github.com/influxdata/influxdb/services/snapshotter/service.go is in golang-github-influxdb-influxdb-dev 1.1.1+dfsg1-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 | package snapshotter // import "github.com/influxdata/influxdb/services/snapshotter"
import (
"bytes"
"encoding"
"encoding/binary"
"encoding/json"
"fmt"
"io"
"log"
"net"
"os"
"strings"
"sync"
"time"
"github.com/influxdata/influxdb"
"github.com/influxdata/influxdb/services/meta"
"github.com/influxdata/influxdb/tsdb"
)
const (
// MuxHeader is the header byte used for the TCP muxer.
MuxHeader = 3
// BackupMagicHeader is the first 8 bytes used to identify and validate
// a metastore backup file
BackupMagicHeader = 0x59590101
)
// Service manages the listener for the snapshot endpoint.
type Service struct {
wg sync.WaitGroup
err chan error
Node *influxdb.Node
MetaClient interface {
encoding.BinaryMarshaler
Database(name string) *meta.DatabaseInfo
}
TSDBStore *tsdb.Store
Listener net.Listener
Logger *log.Logger
}
// NewService returns a new instance of Service.
func NewService() *Service {
return &Service{
err: make(chan error),
Logger: log.New(os.Stderr, "[snapshot] ", log.LstdFlags),
}
}
// Open starts the service.
func (s *Service) Open() error {
s.Logger.Println("Starting snapshot service")
s.wg.Add(1)
go s.serve()
return nil
}
// Close implements the Service interface.
func (s *Service) Close() error {
if s.Listener != nil {
s.Listener.Close()
}
s.wg.Wait()
return nil
}
// SetLogOutput sets the writer to which all logs are written. It must not be
// called after Open is called.
func (s *Service) SetLogOutput(w io.Writer) {
s.Logger = log.New(w, "[snapshot] ", log.LstdFlags)
}
// Err returns a channel for fatal out-of-band errors.
func (s *Service) Err() <-chan error { return s.err }
// serve serves snapshot requests from the listener.
func (s *Service) serve() {
defer s.wg.Done()
for {
// Wait for next connection.
conn, err := s.Listener.Accept()
if err != nil && strings.Contains(err.Error(), "connection closed") {
s.Logger.Println("snapshot listener closed")
return
} else if err != nil {
s.Logger.Println("error accepting snapshot request: ", err.Error())
continue
}
// Handle connection in separate goroutine.
s.wg.Add(1)
go func(conn net.Conn) {
defer s.wg.Done()
defer conn.Close()
if err := s.handleConn(conn); err != nil {
s.Logger.Println(err)
}
}(conn)
}
}
// handleConn processes conn. This is run in a separate goroutine.
func (s *Service) handleConn(conn net.Conn) error {
r, err := s.readRequest(conn)
if err != nil {
return fmt.Errorf("read request: %s", err)
}
switch r.Type {
case RequestShardBackup:
if err := s.TSDBStore.BackupShard(r.ShardID, r.Since, conn); err != nil {
return err
}
case RequestMetastoreBackup:
if err := s.writeMetaStore(conn); err != nil {
return err
}
case RequestDatabaseInfo:
return s.writeDatabaseInfo(conn, r.Database)
case RequestRetentionPolicyInfo:
return s.writeRetentionPolicyInfo(conn, r.Database, r.RetentionPolicy)
default:
return fmt.Errorf("request type unknown: %v", r.Type)
}
return nil
}
func (s *Service) writeMetaStore(conn net.Conn) error {
// Retrieve and serialize the current meta data.
metaBlob, err := s.MetaClient.MarshalBinary()
if err != nil {
return fmt.Errorf("marshal meta: %s", err)
}
var nodeBytes bytes.Buffer
if err := json.NewEncoder(&nodeBytes).Encode(s.Node); err != nil {
return err
}
var numBytes [24]byte
binary.BigEndian.PutUint64(numBytes[:8], BackupMagicHeader)
binary.BigEndian.PutUint64(numBytes[8:16], uint64(len(metaBlob)))
binary.BigEndian.PutUint64(numBytes[16:24], uint64(nodeBytes.Len()))
// backup header followed by meta blob length
if _, err := conn.Write(numBytes[:16]); err != nil {
return err
}
if _, err := conn.Write(metaBlob); err != nil {
return err
}
if _, err := conn.Write(numBytes[16:24]); err != nil {
return err
}
if _, err := nodeBytes.WriteTo(conn); err != nil {
return err
}
return nil
}
// writeDatabaseInfo will write the relative paths of all shards in the database on
// this server into the connection
func (s *Service) writeDatabaseInfo(conn net.Conn, database string) error {
res := Response{}
db := s.MetaClient.Database(database)
if db == nil {
return influxdb.ErrDatabaseNotFound(database)
}
for _, rp := range db.RetentionPolicies {
for _, sg := range rp.ShardGroups {
for _, sh := range sg.Shards {
// ignore if the shard isn't on the server
if s.TSDBStore.Shard(sh.ID) == nil {
continue
}
path, err := s.TSDBStore.ShardRelativePath(sh.ID)
if err != nil {
return err
}
res.Paths = append(res.Paths, path)
}
}
}
if err := json.NewEncoder(conn).Encode(res); err != nil {
return fmt.Errorf("encode resonse: %s", err.Error())
}
return nil
}
// writeDatabaseInfo will write the relative paths of all shards in the retention policy on
// this server into the connection
func (s *Service) writeRetentionPolicyInfo(conn net.Conn, database, retentionPolicy string) error {
res := Response{}
db := s.MetaClient.Database(database)
if db == nil {
return influxdb.ErrDatabaseNotFound(database)
}
var ret *meta.RetentionPolicyInfo
for _, rp := range db.RetentionPolicies {
if rp.Name == retentionPolicy {
ret = &rp
break
}
}
if ret == nil {
return influxdb.ErrRetentionPolicyNotFound(retentionPolicy)
}
for _, sg := range ret.ShardGroups {
for _, sh := range sg.Shards {
// ignore if the shard isn't on the server
if s.TSDBStore.Shard(sh.ID) == nil {
continue
}
path, err := s.TSDBStore.ShardRelativePath(sh.ID)
if err != nil {
return err
}
res.Paths = append(res.Paths, path)
}
}
if err := json.NewEncoder(conn).Encode(res); err != nil {
return fmt.Errorf("encode resonse: %s", err.Error())
}
return nil
}
// readRequest Unmarshals a request object from the conn
func (s *Service) readRequest(conn net.Conn) (Request, error) {
var r Request
if err := json.NewDecoder(conn).Decode(&r); err != nil {
return r, err
}
return r, nil
}
type RequestType uint8
const (
RequestShardBackup RequestType = iota
RequestMetastoreBackup
RequestDatabaseInfo
RequestRetentionPolicyInfo
)
// Request represents a request for a specific backup or for information
// about the shards on this server for a database or retention policy
type Request struct {
Type RequestType
Database string
RetentionPolicy string
ShardID uint64
Since time.Time
}
// Response contains the relative paths for all the shards on this server
// that are in the requested database or retention policy
type Response struct {
Paths []string
}
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