/* Copyright 2016 GitHub Inc. See https://github.com/github/gh-ost/blob/master/LICENSE */ package logic import ( gosql "database/sql" "fmt" "reflect" "strings" "sync/atomic" "time" "github.com/github/gh-ost/go/base" "github.com/github/gh-ost/go/mysql" "github.com/github/gh-ost/go/sql" "github.com/outbrain/golib/log" "github.com/outbrain/golib/sqlutils" ) const startSlavePostWaitMilliseconds = 500 * time.Millisecond // Inspector reads data from the read-MySQL-server (typically a replica, but can be the master) // It is used for gaining initial status and structure, and later also follow up on progress and changelog type Inspector struct { connectionConfig *mysql.ConnectionConfig db *gosql.DB informationSchemaDb *gosql.DB migrationContext *base.MigrationContext } func NewInspector(migrationContext *base.MigrationContext) *Inspector { return &Inspector{ connectionConfig: migrationContext.InspectorConnectionConfig, migrationContext: migrationContext, } } func (this *Inspector) InitDBConnections() (err error) { inspectorUri := this.connectionConfig.GetDBUri(this.migrationContext.DatabaseName) if this.db, _, err = mysql.GetDB(this.migrationContext.Uuid, inspectorUri); err != nil { return err } informationSchemaUri := this.connectionConfig.GetDBUri("information_schema") if this.informationSchemaDb, _, err = mysql.GetDB(this.migrationContext.Uuid, informationSchemaUri); err != nil { return err } if err := this.validateConnection(); err != nil { return err } if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform && !this.migrationContext.AzureMySQL { if impliedKey, err := mysql.GetInstanceKey(this.db); err != nil { return err } else { this.connectionConfig.ImpliedKey = impliedKey } } if err := this.validateGrants(); err != nil { return err } if err := this.validateBinlogs(); err != nil { return err } if err := this.applyBinlogFormat(); err != nil { return err } log.Infof("Inspector initiated on %+v, version %+v", this.connectionConfig.ImpliedKey, this.migrationContext.InspectorMySQLVersion) return nil } func (this *Inspector) ValidateOriginalTable() (err error) { if err := this.validateTable(); err != nil { return err } if err := this.validateTableForeignKeys(this.migrationContext.DiscardForeignKeys); err != nil { return err } if err := this.validateTableTriggers(); err != nil { return err } if err := this.estimateTableRowsViaExplain(); err != nil { return err } return nil } func (this *Inspector) InspectTableColumnsAndUniqueKeys(tableName string) (columns *sql.ColumnList, virtualColumns *sql.ColumnList, uniqueKeys [](*sql.UniqueKey), err error) { uniqueKeys, err = this.getCandidateUniqueKeys(tableName) if err != nil { return columns, virtualColumns, uniqueKeys, err } if len(uniqueKeys) == 0 { return columns, virtualColumns, uniqueKeys, fmt.Errorf("No PRIMARY nor UNIQUE key found in table! Bailing out") } columns, virtualColumns, err = mysql.GetTableColumns(this.db, this.migrationContext.DatabaseName, tableName) if err != nil { return columns, virtualColumns, uniqueKeys, err } return columns, virtualColumns, uniqueKeys, nil } func (this *Inspector) InspectOriginalTable() (err error) { this.migrationContext.OriginalTableColumns, this.migrationContext.OriginalTableVirtualColumns, this.migrationContext.OriginalTableUniqueKeys, err = this.InspectTableColumnsAndUniqueKeys(this.migrationContext.OriginalTableName) if err != nil { return err } return nil } // inspectOriginalAndGhostTables compares original and ghost tables to see whether the migration // makes sense and is valid. It extracts the list of shared columns and the chosen migration unique key func (this *Inspector) inspectOriginalAndGhostTables() (err error) { originalNamesOnApplier := this.migrationContext.OriginalTableColumnsOnApplier.Names() originalNames := this.migrationContext.OriginalTableColumns.Names() if !reflect.DeepEqual(originalNames, originalNamesOnApplier) { return fmt.Errorf("It seems like table structure is not identical between master and replica. This scenario is not supported.") } this.migrationContext.GhostTableColumns, this.migrationContext.GhostTableVirtualColumns, this.migrationContext.GhostTableUniqueKeys, err = this.InspectTableColumnsAndUniqueKeys(this.migrationContext.GetGhostTableName()) if err != nil { return err } sharedUniqueKeys, err := this.getSharedUniqueKeys(this.migrationContext.OriginalTableUniqueKeys, this.migrationContext.GhostTableUniqueKeys) if err != nil { return err } for i, sharedUniqueKey := range sharedUniqueKeys { this.applyColumnTypes(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, &sharedUniqueKey.Columns) uniqueKeyIsValid := true for _, column := range sharedUniqueKey.Columns.Columns() { switch column.Type { case sql.FloatColumnType: { log.Warning("Will not use %+v as shared key due to FLOAT data type", sharedUniqueKey.Name) uniqueKeyIsValid = false } case sql.JSONColumnType: { // Noteworthy that at this time MySQL does not allow JSON indexing anyhow, but this code // will remain in place to potentially handle the future case where JSON is supported in indexes. log.Warning("Will not use %+v as shared key due to JSON data type", sharedUniqueKey.Name) uniqueKeyIsValid = false } } } if uniqueKeyIsValid { this.migrationContext.UniqueKey = sharedUniqueKeys[i] break } } if this.migrationContext.UniqueKey == nil { return fmt.Errorf("No shared unique key can be found after ALTER! Bailing out") } log.Infof("Chosen shared unique key is %s", this.migrationContext.UniqueKey.Name) if this.migrationContext.UniqueKey.HasNullable { if this.migrationContext.NullableUniqueKeyAllowed { log.Warningf("Chosen key (%s) has nullable columns. You have supplied with --allow-nullable-unique-key and so this migration proceeds. As long as there aren't NULL values in this key's column, migration should be fine. NULL values will corrupt migration's data", this.migrationContext.UniqueKey) } else { return fmt.Errorf("Chosen key (%s) has nullable columns. Bailing out. To force this operation to continue, supply --allow-nullable-unique-key flag. Only do so if you are certain there are no actual NULL values in this key. As long as there aren't, migration should be fine. NULL values in columns of this key will corrupt migration's data", this.migrationContext.UniqueKey) } } this.migrationContext.SharedColumns, this.migrationContext.MappedSharedColumns = this.getSharedColumns(this.migrationContext.OriginalTableColumns, this.migrationContext.GhostTableColumns, this.migrationContext.OriginalTableVirtualColumns, this.migrationContext.GhostTableVirtualColumns, this.migrationContext.ColumnRenameMap) log.Infof("Shared columns are %s", this.migrationContext.SharedColumns) // By fact that a non-empty unique key exists we also know the shared columns are non-empty // This additional step looks at which columns are unsigned. We could have merged this within // the `getTableColumns()` function, but it's a later patch and introduces some complexity; I feel // comfortable in doing this as a separate step. this.applyColumnTypes(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, this.migrationContext.OriginalTableColumns, this.migrationContext.SharedColumns, &this.migrationContext.UniqueKey.Columns) this.applyColumnTypes(this.migrationContext.DatabaseName, this.migrationContext.GetGhostTableName(), this.migrationContext.GhostTableColumns, this.migrationContext.MappedSharedColumns) for i := range this.migrationContext.SharedColumns.Columns() { column := this.migrationContext.SharedColumns.Columns()[i] mappedColumn := this.migrationContext.MappedSharedColumns.Columns()[i] if column.Name == mappedColumn.Name && column.Type == sql.DateTimeColumnType && mappedColumn.Type == sql.TimestampColumnType { this.migrationContext.MappedSharedColumns.SetConvertDatetimeToTimestamp(column.Name, this.migrationContext.ApplierTimeZone) } } for _, column := range this.migrationContext.UniqueKey.Columns.Columns() { if this.migrationContext.MappedSharedColumns.HasTimezoneConversion(column.Name) { return fmt.Errorf("No support at this time for converting a column from DATETIME to TIMESTAMP that is also part of the chosen unique key. Column: %s, key: %s", column.Name, this.migrationContext.UniqueKey.Name) } } return nil } // validateConnection issues a simple can-connect to MySQL func (this *Inspector) validateConnection() error { if len(this.connectionConfig.Password) > mysql.MaxReplicationPasswordLength { return fmt.Errorf("MySQL replication length limited to 32 characters. See https://dev.mysql.com/doc/refman/5.7/en/assigning-passwords.html") } version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext) this.migrationContext.InspectorMySQLVersion = version return err } // validateGrants verifies the user by which we're executing has necessary grants // to do its thing. func (this *Inspector) validateGrants() error { query := `show /* gh-ost */ grants for current_user()` foundAll := false foundSuper := false foundReplicationClient := false foundReplicationSlave := false foundDBAll := false err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error { for _, grantData := range rowMap { grant := grantData.String if strings.Contains(grant, `GRANT ALL PRIVILEGES ON *.*`) { foundAll = true } if strings.Contains(grant, `SUPER`) && strings.Contains(grant, ` ON *.*`) { foundSuper = true } if strings.Contains(grant, `REPLICATION CLIENT`) && strings.Contains(grant, ` ON *.*`) { foundReplicationClient = true } if strings.Contains(grant, `REPLICATION SLAVE`) && strings.Contains(grant, ` ON *.*`) { foundReplicationSlave = true } if strings.Contains(grant, fmt.Sprintf("GRANT ALL PRIVILEGES ON `%s`.*", this.migrationContext.DatabaseName)) { foundDBAll = true } if strings.Contains(grant, fmt.Sprintf("GRANT ALL PRIVILEGES ON `%s`.*", strings.Replace(this.migrationContext.DatabaseName, "_", "\\_", -1))) { foundDBAll = true } if base.StringContainsAll(grant, `ALTER`, `CREATE`, `DELETE`, `DROP`, `INDEX`, `INSERT`, `LOCK TABLES`, `SELECT`, `TRIGGER`, `UPDATE`, ` ON *.*`) { foundDBAll = true } if base.StringContainsAll(grant, `ALTER`, `CREATE`, `DELETE`, `DROP`, `INDEX`, `INSERT`, `LOCK TABLES`, `SELECT`, `TRIGGER`, `UPDATE`, fmt.Sprintf(" ON `%s`.*", this.migrationContext.DatabaseName)) { foundDBAll = true } } return nil }) if err != nil { return err } this.migrationContext.HasSuperPrivilege = foundSuper if foundAll { log.Infof("User has ALL privileges") return nil } if foundSuper && foundReplicationSlave && foundDBAll { log.Infof("User has SUPER, REPLICATION SLAVE privileges, and has ALL privileges on %s.*", sql.EscapeName(this.migrationContext.DatabaseName)) return nil } if foundReplicationClient && foundReplicationSlave && foundDBAll { log.Infof("User has REPLICATION CLIENT, REPLICATION SLAVE privileges, and has ALL privileges on %s.*", sql.EscapeName(this.migrationContext.DatabaseName)) return nil } log.Debugf("Privileges: Super: %t, REPLICATION CLIENT: %t, REPLICATION SLAVE: %t, ALL on *.*: %t, ALL on %s.*: %t", foundSuper, foundReplicationClient, foundReplicationSlave, foundAll, sql.EscapeName(this.migrationContext.DatabaseName), foundDBAll) return log.Errorf("User has insufficient privileges for migration. Needed: SUPER|REPLICATION CLIENT, REPLICATION SLAVE and ALL on %s.*", sql.EscapeName(this.migrationContext.DatabaseName)) } // restartReplication is required so that we are _certain_ the binlog format and // row image settings have actually been applied to the replication thread. // It is entirely possible, for example, that the replication is using 'STATEMENT' // binlog format even as the variable says 'ROW' func (this *Inspector) restartReplication() error { log.Infof("Restarting replication on %s:%d to make sure binlog settings apply to replication thread", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) masterKey, _ := mysql.GetMasterKeyFromSlaveStatus(this.connectionConfig) if masterKey == nil { // This is not a replica return nil } var stopError, startError error _, stopError = sqlutils.ExecNoPrepare(this.db, `stop slave`) _, startError = sqlutils.ExecNoPrepare(this.db, `start slave`) if stopError != nil { return stopError } if startError != nil { return startError } time.Sleep(startSlavePostWaitMilliseconds) log.Debugf("Replication restarted") return nil } // applyBinlogFormat sets ROW binlog format and restarts replication to make // the replication thread apply it. func (this *Inspector) applyBinlogFormat() error { if this.migrationContext.RequiresBinlogFormatChange() { if !this.migrationContext.SwitchToRowBinlogFormat { return fmt.Errorf("Existing binlog_format is %s. Am not switching it to ROW unless you specify --switch-to-rbr", this.migrationContext.OriginalBinlogFormat) } if _, err := sqlutils.ExecNoPrepare(this.db, `set global binlog_format='ROW'`); err != nil { return err } if _, err := sqlutils.ExecNoPrepare(this.db, `set session binlog_format='ROW'`); err != nil { return err } if err := this.restartReplication(); err != nil { return err } log.Debugf("'ROW' binlog format applied") return nil } // We already have RBR, no explicit switch if !this.migrationContext.AssumeRBR { if err := this.restartReplication(); err != nil { return err } } return nil } // validateBinlogs checks that binary log configuration is good to go func (this *Inspector) validateBinlogs() error { query := `select @@global.log_bin, @@global.binlog_format` var hasBinaryLogs bool if err := this.db.QueryRow(query).Scan(&hasBinaryLogs, &this.migrationContext.OriginalBinlogFormat); err != nil { return err } if !hasBinaryLogs { return fmt.Errorf("%s:%d must have binary logs enabled", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) } if this.migrationContext.RequiresBinlogFormatChange() { if !this.migrationContext.SwitchToRowBinlogFormat { return fmt.Errorf("You must be using ROW binlog format. I can switch it for you, provided --switch-to-rbr and that %s:%d doesn't have replicas", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) } query := fmt.Sprintf(`show /* gh-ost */ slave hosts`) countReplicas := 0 err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error { countReplicas++ return nil }) if err != nil { 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.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogFormat) } log.Infof("%s:%d has %s binlog_format. I will change it to ROW, and will NOT change it back, even in the event of failure.", 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 { // Only as of 5.6. We wish to support 5.5 as well this.migrationContext.OriginalBinlogRowImage = "FULL" } this.migrationContext.OriginalBinlogRowImage = strings.ToUpper(this.migrationContext.OriginalBinlogRowImage) if this.migrationContext.OriginalBinlogRowImage != "FULL" { return fmt.Errorf("%s:%d has '%s' binlog_row_image, and only 'FULL' is supported. This operation cannot proceed. You may `set global binlog_row_image='full'` and try again", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogRowImage) } log.Infof("binary logs validated on %s:%d", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) return nil } // validateLogSlaveUpdates checks that binary log log_slave_updates is set. This test is not required when migrating on replica or when migrating directly on master func (this *Inspector) validateLogSlaveUpdates() error { query := `select @@global.log_slave_updates` var logSlaveUpdates bool if err := this.db.QueryRow(query).Scan(&logSlaveUpdates); err != nil { return err } if logSlaveUpdates { log.Infof("log_slave_updates validated on %s:%d", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) return nil } if this.migrationContext.IsTungsten { log.Warningf("log_slave_updates not found on %s:%d, but --tungsten provided, so I'm proceeding", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) return nil } if this.migrationContext.TestOnReplica || this.migrationContext.MigrateOnReplica { return fmt.Errorf("%s:%d must have log_slave_updates enabled for testing/migrating on replica", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) } if this.migrationContext.InspectorIsAlsoApplier() { log.Warningf("log_slave_updates not found on %s:%d, but executing directly on master, so I'm proceeding", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) return nil } return fmt.Errorf("%s:%d must have log_slave_updates enabled for executing migration", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port) } // validateTable makes sure the table we need to operate on actually exists func (this *Inspector) validateTable() error { query := fmt.Sprintf(`show /* gh-ost */ table status from %s like '%s'`, sql.EscapeName(this.migrationContext.DatabaseName), this.migrationContext.OriginalTableName) tableFound := false err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error { this.migrationContext.TableEngine = rowMap.GetString("Engine") this.migrationContext.RowsEstimate = rowMap.GetInt64("Rows") this.migrationContext.UsedRowsEstimateMethod = base.TableStatusRowsEstimate if rowMap.GetString("Comment") == "VIEW" { return fmt.Errorf("%s.%s is a VIEW, not a real table. Bailing out", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } tableFound = true return nil }) if err != nil { return err } if !tableFound { return log.Errorf("Cannot find table %s.%s!", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } log.Infof("Table found. Engine=%s", this.migrationContext.TableEngine) log.Debugf("Estimated number of rows via STATUS: %d", this.migrationContext.RowsEstimate) return nil } // validateTableForeignKeys makes sure no foreign keys exist on the migrated table func (this *Inspector) validateTableForeignKeys(allowChildForeignKeys bool) error { if this.migrationContext.SkipForeignKeyChecks { log.Warning("--skip-foreign-key-checks provided: will not check for foreign keys") return nil } query := ` SELECT SUM(REFERENCED_TABLE_NAME IS NOT NULL AND TABLE_SCHEMA=? AND TABLE_NAME=?) as num_child_side_fk, SUM(REFERENCED_TABLE_NAME IS NOT NULL AND REFERENCED_TABLE_SCHEMA=? AND REFERENCED_TABLE_NAME=?) as num_parent_side_fk FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_NAME IS NOT NULL AND ((TABLE_SCHEMA=? AND TABLE_NAME=?) OR (REFERENCED_TABLE_SCHEMA=? AND REFERENCED_TABLE_NAME=?) ) ` numParentForeignKeys := 0 numChildForeignKeys := 0 err := sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error { numChildForeignKeys = m.GetInt("num_child_side_fk") numParentForeignKeys = m.GetInt("num_parent_side_fk") return nil }, this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, ) if err != nil { return err } if numParentForeignKeys > 0 { return log.Errorf("Found %d parent-side foreign keys on %s.%s. Parent-side foreign keys are not supported. Bailing out", numParentForeignKeys, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } if numChildForeignKeys > 0 { if allowChildForeignKeys { log.Debugf("Foreign keys found and will be dropped, as per given --discard-foreign-keys flag") return nil } return log.Errorf("Found %d child-side foreign keys on %s.%s. Child-side foreign keys are not supported. Bailing out", numChildForeignKeys, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } log.Debugf("Validated no foreign keys exist on table") return nil } // validateTableTriggers makes sure no triggers exist on the migrated table func (this *Inspector) validateTableTriggers() error { query := ` SELECT COUNT(*) AS num_triggers FROM INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_SCHEMA=? AND EVENT_OBJECT_TABLE=? ` numTriggers := 0 err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error { numTriggers = rowMap.GetInt("num_triggers") return nil }, this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, ) if err != nil { return err } if numTriggers > 0 { return log.Errorf("Found triggers on %s.%s. Triggers are not supported at this time. Bailing out", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } log.Debugf("Validated no triggers exist on table") return nil } // estimateTableRowsViaExplain estimates number of rows on original table func (this *Inspector) estimateTableRowsViaExplain() error { query := fmt.Sprintf(`explain select /* gh-ost */ * from %s.%s where 1=1`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) outputFound := false err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error { this.migrationContext.RowsEstimate = rowMap.GetInt64("rows") this.migrationContext.UsedRowsEstimateMethod = base.ExplainRowsEstimate outputFound = true return nil }) if err != nil { return err } if !outputFound { return log.Errorf("Cannot run EXPLAIN on %s.%s!", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) } log.Infof("Estimated number of rows via EXPLAIN: %d", this.migrationContext.RowsEstimate) return nil } // CountTableRows counts exact number of rows on the original table func (this *Inspector) CountTableRows() error { atomic.StoreInt64(&this.migrationContext.CountingRowsFlag, 1) defer atomic.StoreInt64(&this.migrationContext.CountingRowsFlag, 0) log.Infof("As instructed, I'm issuing a SELECT COUNT(*) on the table. This may take a while") query := fmt.Sprintf(`select /* gh-ost */ count(*) as rows from %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName)) var rowsEstimate int64 if err := this.db.QueryRow(query).Scan(&rowsEstimate); err != nil { return err } atomic.StoreInt64(&this.migrationContext.RowsEstimate, rowsEstimate) this.migrationContext.UsedRowsEstimateMethod = base.CountRowsEstimate log.Infof("Exact number of rows via COUNT: %d", rowsEstimate) return nil } // applyColumnTypes func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsLists ...*sql.ColumnList) error { query := ` select * from information_schema.columns where table_schema=? and table_name=? ` err := sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error { columnName := m.GetString("COLUMN_NAME") columnType := m.GetString("COLUMN_TYPE") for _, columnsList := range columnsLists { column := columnsList.GetColumn(columnName) if column == nil { continue } if strings.Contains(columnType, "unsigned") { column.IsUnsigned = true } if strings.Contains(columnType, "mediumint") { column.Type = sql.MediumIntColumnType } if strings.Contains(columnType, "timestamp") { column.Type = sql.TimestampColumnType } if strings.Contains(columnType, "datetime") { column.Type = sql.DateTimeColumnType } if strings.Contains(columnType, "json") { column.Type = sql.JSONColumnType } if strings.Contains(columnType, "float") { column.Type = sql.FloatColumnType } if strings.HasPrefix(columnType, "enum") { column.Type = sql.EnumColumnType } if charset := m.GetString("CHARACTER_SET_NAME"); charset != "" { column.Charset = charset } } return nil }, databaseName, tableName) return err } // getCandidateUniqueKeys investigates a table and returns the list of unique keys // candidate for chunking func (this *Inspector) getCandidateUniqueKeys(tableName string) (uniqueKeys [](*sql.UniqueKey), err error) { query := ` SELECT COLUMNS.TABLE_SCHEMA, COLUMNS.TABLE_NAME, COLUMNS.COLUMN_NAME, UNIQUES.INDEX_NAME, UNIQUES.COLUMN_NAMES, UNIQUES.COUNT_COLUMN_IN_INDEX, COLUMNS.DATA_TYPE, COLUMNS.CHARACTER_SET_NAME, LOCATE('auto_increment', EXTRA) > 0 as is_auto_increment, has_nullable FROM INFORMATION_SCHEMA.COLUMNS INNER JOIN ( SELECT TABLE_SCHEMA, TABLE_NAME, INDEX_NAME, COUNT(*) AS COUNT_COLUMN_IN_INDEX, GROUP_CONCAT(COLUMN_NAME ORDER BY SEQ_IN_INDEX ASC) AS COLUMN_NAMES, SUBSTRING_INDEX(GROUP_CONCAT(COLUMN_NAME ORDER BY SEQ_IN_INDEX ASC), ',', 1) AS FIRST_COLUMN_NAME, SUM(NULLABLE='YES') > 0 AS has_nullable FROM INFORMATION_SCHEMA.STATISTICS WHERE NON_UNIQUE=0 AND TABLE_SCHEMA = ? AND TABLE_NAME = ? GROUP BY TABLE_SCHEMA, TABLE_NAME, INDEX_NAME ) AS UNIQUES ON ( COLUMNS.COLUMN_NAME = UNIQUES.FIRST_COLUMN_NAME ) WHERE COLUMNS.TABLE_SCHEMA = ? AND COLUMNS.TABLE_NAME = ? ORDER BY COLUMNS.TABLE_SCHEMA, COLUMNS.TABLE_NAME, CASE UNIQUES.INDEX_NAME WHEN 'PRIMARY' THEN 0 ELSE 1 END, CASE has_nullable WHEN 0 THEN 0 ELSE 1 END, CASE IFNULL(CHARACTER_SET_NAME, '') WHEN '' THEN 0 ELSE 1 END, CASE DATA_TYPE WHEN 'tinyint' THEN 0 WHEN 'smallint' THEN 1 WHEN 'int' THEN 2 WHEN 'bigint' THEN 3 ELSE 100 END, COUNT_COLUMN_IN_INDEX ` err = sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error { uniqueKey := &sql.UniqueKey{ Name: m.GetString("INDEX_NAME"), Columns: *sql.ParseColumnList(m.GetString("COLUMN_NAMES")), HasNullable: m.GetBool("has_nullable"), IsAutoIncrement: m.GetBool("is_auto_increment"), } uniqueKeys = append(uniqueKeys, uniqueKey) return nil }, this.migrationContext.DatabaseName, tableName, this.migrationContext.DatabaseName, tableName) if err != nil { return uniqueKeys, err } log.Debugf("Potential unique keys in %+v: %+v", tableName, uniqueKeys) return uniqueKeys, nil } // getSharedUniqueKeys returns the intersection of two given unique keys, // testing by list of columns func (this *Inspector) getSharedUniqueKeys(originalUniqueKeys, ghostUniqueKeys [](*sql.UniqueKey)) (uniqueKeys [](*sql.UniqueKey), err error) { // We actually do NOT rely on key name, just on the set of columns. This is because maybe // the ALTER is on the name itself... for _, originalUniqueKey := range originalUniqueKeys { for _, ghostUniqueKey := range ghostUniqueKeys { if originalUniqueKey.Columns.EqualsByNames(&ghostUniqueKey.Columns) { uniqueKeys = append(uniqueKeys, originalUniqueKey) } } } return uniqueKeys, nil } // getSharedColumns returns the intersection of two lists of columns in same order as the first list func (this *Inspector) getSharedColumns(originalColumns, ghostColumns *sql.ColumnList, originalVirtualColumns, ghostVirtualColumns *sql.ColumnList, columnRenameMap map[string]string) (*sql.ColumnList, *sql.ColumnList) { sharedColumnNames := []string{} for _, originalColumn := range originalColumns.Names() { isSharedColumn := false for _, ghostColumn := range ghostColumns.Names() { if strings.EqualFold(originalColumn, ghostColumn) { isSharedColumn = true break } if strings.EqualFold(columnRenameMap[originalColumn], ghostColumn) { isSharedColumn = true break } } for droppedColumn := range this.migrationContext.DroppedColumnsMap { if strings.EqualFold(originalColumn, droppedColumn) { isSharedColumn = false break } } for _, virtualColumn := range originalVirtualColumns.Names() { if strings.EqualFold(originalColumn, virtualColumn) { isSharedColumn = false } } for _, virtualColumn := range ghostVirtualColumns.Names() { if strings.EqualFold(originalColumn, virtualColumn) { isSharedColumn = false } } if isSharedColumn { sharedColumnNames = append(sharedColumnNames, originalColumn) } } mappedSharedColumnNames := []string{} for _, columnName := range sharedColumnNames { if mapped, ok := columnRenameMap[columnName]; ok { mappedSharedColumnNames = append(mappedSharedColumnNames, mapped) } else { mappedSharedColumnNames = append(mappedSharedColumnNames, columnName) } } return sql.NewColumnList(sharedColumnNames), sql.NewColumnList(mappedSharedColumnNames) } // showCreateTable returns the `show create table` statement for given table func (this *Inspector) showCreateTable(tableName string) (createTableStatement string, err error) { var dummy string query := fmt.Sprintf(`show /* gh-ost */ create table %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(tableName)) err = this.db.QueryRow(query).Scan(&dummy, &createTableStatement) return createTableStatement, err } // readChangelogState reads changelog hints func (this *Inspector) readChangelogState(hint string) (string, error) { query := fmt.Sprintf(` select hint, value from %s.%s where hint = ? and id <= 255 `, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.GetChangelogTableName()), ) result := "" err := sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error { result = m.GetString("value") return nil }, hint) return result, err } func (this *Inspector) getMasterConnectionConfig() (applierConfig *mysql.ConnectionConfig, err error) { log.Infof("Recursively searching for replication master") visitedKeys := mysql.NewInstanceKeyMap() return mysql.GetMasterConnectionConfigSafe(this.connectionConfig, visitedKeys, this.migrationContext.AllowedMasterMaster) } func (this *Inspector) getReplicationLag() (replicationLag time.Duration, err error) { replicationLag, err = mysql.GetReplicationLagFromSlaveStatus( this.informationSchemaDb, ) return replicationLag, err } func (this *Inspector) Teardown() { this.db.Close() this.informationSchemaDb.Close() return }