// open opens the the in-memory or file-based database.
func (s *Store) open() (*sql.DB, error) {
var db *sql.DB
var err error
if !s.dbConf.Memory {
// as it will be rebuilt from (possibly) a snapshot and committed log entries.
if err := os.Remove(s.dbPath); err != nil && !os.IsNotExist(err) {
return nil, err
}
db, err = sql.OpenWithDSN(s.dbPath, s.dbConf.DSN)
if err != nil {
return nil, err
}
s.logger.Println("SQLite database opened at", s.dbPath)
} else {
db, err = sql.OpenInMemoryWithDSN(s.dbConf.DSN)
if err != nil {
return nil, err
}
s.logger.Println("SQLite in-memory database opened")
}
return db, nil
}
// Open opens the store. If enableSingle is set, and there are no existing peers,
// then this node becomes the first node, and therefore leader, of the cluster.
func (s *Store) Open(enableSingle bool) error {
if err := os.MkdirAll(s.raftDir, 0755); err != nil {
return err
}
// Create the database. Unless it's a memory-based database, it must be deleted
var db *sql.DB
var err error
if !s.dbConf.Memory {
// as it will be rebuilt from (possibly) a snapshot and committed log entries.
if err := os.Remove(s.dbPath); err != nil && !os.IsNotExist(err) {
return err
}
db, err = sql.OpenWithDSN(s.dbPath, s.dbConf.DSN)
if err != nil {
return err
}
s.logger.Println("SQLite database opened at", s.dbPath)
} else {
db, err = sql.OpenInMemoryWithDSN(s.dbConf.DSN)
if err != nil {
return err
}
s.logger.Println("SQLite in-memory database opened")
}
s.db = db
// Setup Raft configuration.
config := raft.DefaultConfig()
// Check for any existing peers.
peers, err := readPeersJSON(filepath.Join(s.raftDir, "peers.json"))
if err != nil {
return err
}
s.joinRequired = len(peers) <= 1
// Allow the node to entry single-mode, potentially electing itself, if
// explicitly enabled and there is only 1 node in the cluster already.
if enableSingle && len(peers) <= 1 {
s.logger.Println("enabling single-node mode")
config.EnableSingleNode = true
config.DisableBootstrapAfterElect = false
}
// Setup Raft communication.
transport := raft.NewNetworkTransport(s.raftTransport, 3, 10*time.Second, os.Stderr)
// Create peer storage.
peerStore := raft.NewJSONPeers(s.raftDir, transport)
// Create the snapshot store. This allows Raft to truncate the log.
snapshots, err := raft.NewFileSnapshotStore(s.raftDir, retainSnapshotCount, os.Stderr)
if err != nil {
return fmt.Errorf("file snapshot store: %s", err)
}
// Create the log store and stable store.
logStore, err := raftboltdb.NewBoltStore(filepath.Join(s.raftDir, "raft.db"))
if err != nil {
return fmt.Errorf("new bolt store: %s", err)
}
// Instantiate the Raft system.
ra, err := raft.NewRaft(config, s, logStore, logStore, snapshots, peerStore, transport)
if err != nil {
return fmt.Errorf("new raft: %s", err)
}
s.raft = ra
return nil
}