octoleo/gh-ost
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

detecting master (includes sanity checks). Introducing Applier. Creating and altering ghost table

Browse Source
This commit is contained in:
Shlomi Noach 2016-04-04 15:29:02 +02:00
parent bba352922a
commit cf87d16044
6 changed files with 163 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
go/base/context.go
View File

@ -5,7 +5,11 @@
package base
import ()
import (
"fmt"
"github.com/github/gh-osc/go/mysql"
)
type RowsEstimateMethod string
@ -18,7 +22,6 @@ const (
type MigrationContext struct {
DatabaseName string
OriginalTableName string
GhostTableName string
AlterStatement string
TableEngine string
CountTableRows bool
@ -27,6 +30,9 @@ type MigrationContext struct {
ChunkSize int
OriginalBinlogFormat string
OriginalBinlogRowImage string
AllowedRunningOnMaster bool
InspectorConnectionConfig *mysql.ConnectionConfig
MasterConnectionConfig *mysql.ConnectionConfig
}
var context *MigrationContext
@ -38,6 +44,8 @@ func init() {
func newMigrationContext() *MigrationContext {
return &MigrationContext{
ChunkSize: 1000,
InspectorConnectionConfig: mysql.NewConnectionConfig(),
MasterConnectionConfig: mysql.NewConnectionConfig(),
}
}
@ -45,7 +53,16 @@ func GetMigrationContext() *MigrationContext {
return context
}
func (this *MigrationContext) GetGhostTableName() string {
return fmt.Sprintf("_%s_New", this.OriginalTableName)
}
// RequiresBinlogFormatChange
func (this *MigrationContext) RequiresBinlogFormatChange() bool {
return this.OriginalBinlogFormat != "ROW"
}
// RequiresBinlogFormatChange
func (this *MigrationContext) IsRunningOnMaster() bool {
return this.InspectorConnectionConfig.Equals(this.MasterConnectionConfig)
}

2
go/binlog/gomysql_reader.go
View File

@ -35,7 +35,7 @@ func NewGoMySQLReader(connectionConfig *mysql.ConnectionConfig) (binlogReader *G
binlogReader.binlogSyncer = replication.NewBinlogSyncer(serverId, "mysql")
// Register slave, the MySQL master is at 127.0.0.1:3306, with user root and an empty password
err = binlogReader.binlogSyncer.RegisterSlave(connectionConfig.Hostname, uint16(connectionConfig.Port), connectionConfig.User, connectionConfig.Password)
err = binlogReader.binlogSyncer.RegisterSlave(connectionConfig.Key.Hostname, uint16(connectionConfig.Key.Port), connectionConfig.User, connectionConfig.Password)
if err != nil {
return binlogReader, err
}

15
go/cmd/gh-osc/main.go
View File

@ -13,13 +13,11 @@ import (
"github.com/github/gh-osc/go/base"
"github.com/github/gh-osc/go/binlog"
"github.com/github/gh-osc/go/logic"
"github.com/github/gh-osc/go/mysql"
"github.com/outbrain/golib/log"
)
// main is the application's entry point. It will either spawn a CLI or HTTP itnerfaces.
func main() {
var connectionConfig mysql.ConnectionConfig
migrationContext := base.GetMigrationContext()
// mysqlBasedir := flag.String("mysql-basedir", "", "the --basedir config for MySQL (auto-detected if not given)")
@ -27,15 +25,16 @@ func main() {
internalExperiment := flag.Bool("internal-experiment", false, "issue an internal experiment")
binlogFile := flag.String("binlog-file", "", "Name of binary log file")
flag.StringVar(&connectionConfig.Hostname, "host", "127.0.0.1", "MySQL hostname (preferably a replica, not the master)")
flag.IntVar(&connectionConfig.Port, "port", 3306, "MySQL port (preferably a replica, not the master)")
flag.StringVar(&connectionConfig.User, "user", "root", "MySQL user")
flag.StringVar(&connectionConfig.Password, "password", "", "MySQL password")
flag.StringVar(&migrationContext.InspectorConnectionConfig.Key.Hostname, "host", "127.0.0.1", "MySQL hostname (preferably a replica, not the master)")
flag.IntVar(&migrationContext.InspectorConnectionConfig.Key.Port, "port", 3306, "MySQL port (preferably a replica, not the master)")
flag.StringVar(&migrationContext.InspectorConnectionConfig.User, "user", "root", "MySQL user")
flag.StringVar(&migrationContext.InspectorConnectionConfig.Password, "password", "", "MySQL password")
flag.StringVar(&migrationContext.DatabaseName, "database", "", "database name (mandatory)")
flag.StringVar(&migrationContext.OriginalTableName, "table", "", "table name (mandatory)")
flag.StringVar(&migrationContext.AlterStatement, "alter", "", "alter statement (mandatory)")
flag.BoolVar(&migrationContext.CountTableRows, "exact-rowcount", false, "actually count table rows as opposed to estimate them (results in more accurate progress estimation)")
flag.BoolVar(&migrationContext.AllowedRunningOnMaster, "allow-on-master", false, "allow this migration to run directly on master. Preferably it would run on a replica")
quiet := flag.Bool("quiet", false, "quiet")
verbose := flag.Bool("verbose", false, "verbose")
@ -83,14 +82,14 @@ func main() {
var err error
//binlogReader = binlog.NewMySQLBinlogReader(*mysqlBasedir, *mysqlDatadir)
binlogReader, err = binlog.NewGoMySQLReader(&connectionConfig)
binlogReader, err = binlog.NewGoMySQLReader(migrationContext.InspectorConnectionConfig)
if err != nil {
log.Fatale(err)
}
binlogReader.ReadEntries(*binlogFile, 0, 0)
return
}
migrator := logic.NewMigrator(&connectionConfig)
migrator := logic.NewMigrator()
err := migrator.Migrate()
if err != nil {
log.Fatale(err)

74
go/logic/inspect.go
View File

@ -26,15 +26,15 @@ type Inspector struct {
migrationContext *base.MigrationContext
}
func NewInspector(connectionConfig *mysql.ConnectionConfig) *Inspector {
func NewInspector() *Inspector {
return &Inspector{
connectionConfig: connectionConfig,
connectionConfig: base.GetMigrationContext().InspectorConnectionConfig,
migrationContext: base.GetMigrationContext(),
}
}
func (this *Inspector) InitDBConnections() (err error) {
inspectorUri := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", this.connectionConfig.User, this.connectionConfig.Password, this.connectionConfig.Hostname, this.connectionConfig.Port, this.migrationContext.DatabaseName)
inspectorUri := this.connectionConfig.GetDBUri(this.migrationContext.DatabaseName)
if this.db, _, err = sqlutils.GetDB(inspectorUri); err != nil {
return err
}
@ -59,7 +59,6 @@ func (this *Inspector) InitDBConnections() (err error) {
return err
}
}
return nil
}
@ -76,15 +75,15 @@ func (this *Inspector) InspectTables() (err error) {
// validateConnection issues a simple can-connect to MySQL
func (this *Inspector) validateConnection() error {
query := `select @@port`
query := `select @@global.port`
var port int
if err := this.db.QueryRow(query).Scan(&port); err != nil {
return err
}
if port != this.connectionConfig.Port {
if port != this.connectionConfig.Key.Port {
return fmt.Errorf("Unexpected database port reported: %+v", port)
}
log.Infof("connection validated on port %+v", port)
log.Infof("connection validated on %+v", this.connectionConfig.Key)
return nil
}
@ -116,7 +115,7 @@ func (this *Inspector) validateGrants() error {
return nil
})
if err != nil {
return log.Errore(err)
return err
}
if foundAll {
@ -138,10 +137,10 @@ func (this *Inspector) validateBinlogs() error {
return err
}
if !hasBinaryLogs {
return fmt.Errorf("%s:%d must have binary logs enabled", this.connectionConfig.Hostname, this.connectionConfig.Port)
return fmt.Errorf("%s:%d must have binary logs enabled", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
}
if !logSlaveUpdates {
return fmt.Errorf("%s:%d must have log_slave_updates enabled", this.connectionConfig.Hostname, this.connectionConfig.Port)
return fmt.Errorf("%s:%d must have log_slave_updates enabled", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
}
if this.migrationContext.RequiresBinlogFormatChange() {
query := fmt.Sprintf(`show /* gh-osc */ slave hosts`)
@ -151,12 +150,12 @@ func (this *Inspector) validateBinlogs() error {
return nil
})
if err != nil {
return log.Errore(err)
return err
}
if countReplicas > 0 {
return fmt.Errorf("%s:%d has %s binlog_format, but I'm too scared to change it to ROW because it has replicas. Bailing out", this.connectionConfig.Hostname, this.connectionConfig.Port, this.migrationContext.OriginalBinlogFormat)
return fmt.Errorf("%s:%d has %s binlog_format, but I'm too scared to change it to ROW because it has replicas. Bailing out", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogFormat)
}
log.Infof("%s:%d has %s binlog_format. I will change it to ROW for the duration of this migration.", this.connectionConfig.Hostname, this.connectionConfig.Port, this.migrationContext.OriginalBinlogFormat)
log.Infof("%s:%d has %s binlog_format. I will change it to ROW for the duration of this migration.", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogFormat)
}
query = `select @@global.binlog_row_image`
if err := this.db.QueryRow(query).Scan(&this.migrationContext.OriginalBinlogRowImage); err != nil {
@ -164,7 +163,7 @@ func (this *Inspector) validateBinlogs() error {
this.migrationContext.OriginalBinlogRowImage = ""
}
log.Infof("binary logs validated on %s:%d", this.connectionConfig.Hostname, this.connectionConfig.Port)
log.Infof("binary logs validated on %s:%d", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
return nil
}
@ -185,7 +184,7 @@ func (this *Inspector) validateTable() error {
return nil
})
if err != nil {
return log.Errore(err)
return err
}
if !tableFound {
return log.Errorf("Cannot find table %s.%s!", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
@ -207,7 +206,7 @@ func (this *Inspector) estimateTableRowsViaExplain() error {
return nil
})
if err != nil {
return log.Errore(err)
return err
}
if !outputFound {
return log.Errorf("Cannot run EXPLAIN on %s.%s!", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
@ -308,7 +307,7 @@ func (this *Inspector) getSharedUniqueKeys() (uniqueKeys [](*sql.UniqueKey), err
if err != nil {
return uniqueKeys, err
}
ghostUniqueKeys, err := this.getCandidateUniqueKeys(this.migrationContext.GhostTableName)
ghostUniqueKeys, err := this.getCandidateUniqueKeys(this.migrationContext.GetGhostTableName())
if err != nil {
return uniqueKeys, err
}
@ -323,3 +322,44 @@ func (this *Inspector) getSharedUniqueKeys() (uniqueKeys [](*sql.UniqueKey), err
}
return uniqueKeys, nil
}
func (this *Inspector) getMasterConnectionConfig() (masterConfig *mysql.ConnectionConfig, err error) {
visitedKeys := mysql.NewInstanceKeyMap()
return getMasterConnectionConfigSafe(this.connectionConfig, this.migrationContext.DatabaseName, visitedKeys)
}
func getMasterConnectionConfigSafe(connectionConfig *mysql.ConnectionConfig, databaseName string, visitedKeys *mysql.InstanceKeyMap) (masterConfig *mysql.ConnectionConfig, err error) {
log.Debugf("Looking for master on %+v", connectionConfig.Key)
currentUri := connectionConfig.GetDBUri(databaseName)
db, _, err := sqlutils.GetDB(currentUri)
if err != nil {
return nil, err
}
hasMaster := false
masterConfig = connectionConfig.Duplicate()
err = sqlutils.QueryRowsMap(db, `show slave status`, func(rowMap sqlutils.RowMap) error {
masterKey := mysql.InstanceKey{
Hostname: rowMap.GetString("Master_Host"),
Port: rowMap.GetInt("Master_Port"),
}
if masterKey.IsValid() {
masterConfig.Key = masterKey
hasMaster = true
}
return nil
})
if err != nil {
return nil, err
}
if hasMaster {
log.Debugf("Master of %+v is %+v", connectionConfig.Key, masterConfig.Key)
if visitedKeys.HasKey(masterConfig.Key) {
return nil, fmt.Errorf("There seems to be a master-master setup at %+v. This is unsupported. Bailing out", masterConfig.Key)
}
visitedKeys.AddKey(masterConfig.Key)
return getMasterConnectionConfigSafe(masterConfig, databaseName, visitedKeys)
}
return masterConfig, nil
}

38
go/logic/migrator.go
View File

@ -6,28 +6,54 @@
package logic
import (
"github.com/github/gh-osc/go/mysql"
"fmt"
"github.com/github/gh-osc/go/base"
"github.com/outbrain/golib/log"
)
// Migrator is the main schema migration flow manager.
type Migrator struct {
connectionConfig *mysql.ConnectionConfig
inspector *Inspector
applier *Applier
migrationContext *base.MigrationContext
}
func NewMigrator(connectionConfig *mysql.ConnectionConfig) *Migrator {
func NewMigrator() *Migrator {
return &Migrator{
connectionConfig: connectionConfig,
inspector: NewInspector(connectionConfig),
migrationContext: base.GetMigrationContext(),
}
}
func (this *Migrator) Migrate() error {
func (this *Migrator) Migrate() (err error) {
this.inspector = NewInspector()
if err := this.inspector.InitDBConnections(); err != nil {
return err
}
if this.migrationContext.MasterConnectionConfig, err = this.inspector.getMasterConnectionConfig(); err != nil {
return err
}
if this.migrationContext.IsRunningOnMaster() && !this.migrationContext.AllowedRunningOnMaster {
return fmt.Errorf("It seems like this migration attempt to run directly on master. Preferably it would be executed on a replica (and this reduces load from the master). To proceed please provide --allow-on-master")
}
log.Infof("Master found to be %+v", this.migrationContext.MasterConnectionConfig.Key)
if err := this.inspector.InspectTables(); err != nil {
return err
}
this.applier = NewApplier()
if err := this.applier.InitDBConnections(); err != nil {
return err
}
if err := this.applier.CreateGhostTable(); err != nil {
log.Errorf("Unable to create ghost table, see further error details. Perhaps a previous migration failed without dropping the table? Bailing out")
return err
}
if err := this.applier.AlterGhost(); err != nil {
log.Errorf("Unable to ALTER ghost table, see further error details. Bailing out")
return err
}
return nil
}

38
go/mysql/connection.go
View File

@ -5,10 +5,44 @@
package mysql
import (
"fmt"
)
// ConnectionConfig is the minimal configuration required to connect to a MySQL server
type ConnectionConfig struct {
Hostname string
Port int
Key InstanceKey
User string
Password string
}
func NewConnectionConfig() *ConnectionConfig {
config := &ConnectionConfig{
Key: InstanceKey{},
}
return config
}
func (this *ConnectionConfig) Duplicate() *ConnectionConfig {
config := &ConnectionConfig{
Key: InstanceKey{
Hostname: this.Key.Hostname,
Port: this.Key.Port,
},
User: this.User,
Password: this.Password,
}
return config
}
func (this *ConnectionConfig) String() string {
return fmt.Sprintf("%s, user=%s", this.Key.DisplayString(), this.User)
}
func (this *ConnectionConfig) Equals(other *ConnectionConfig) bool {
return this.Key.Equals(&other.Key)
}
func (this *ConnectionConfig) GetDBUri(databaseName string) string {
return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", this.User, this.Password, this.Key.Hostname, this.Key.Port, databaseName)
}