Golang Wrangler.TabletManagerClient方法代码示例

func commandRestoreFromBackup(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("The RestoreFromBackup command requires the <tablet alias> argument.")
	}

	tabletAlias, err := topoproto.ParseTabletAlias(subFlags.Arg(0))
	if err != nil {
		return err
	}
	tabletInfo, err := wr.TopoServer().GetTablet(ctx, tabletAlias)
	if err != nil {
		return err
	}
	stream, err := wr.TabletManagerClient().RestoreFromBackup(ctx, tabletInfo.Tablet)
	if err != nil {
		return err
	}
	for {
		e, err := stream.Recv()
		switch err {
		case nil:
			logutil.LogEvent(wr.Logger(), e)
		case io.EOF:
			return nil
		default:
			return err
		}
	}
}

func commandDemoteMaster(wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("action DemoteMaster requires <tablet alias|zk tablet path>")
	}
	tabletAlias, err := tabletParamToTabletAlias(subFlags.Arg(0))
	if err != nil {
		return err
	}
	tabletInfo, err := wr.TopoServer().GetTablet(tabletAlias)
	if err != nil {
		return err
	}
	return wr.TabletManagerClient().DemoteMaster(tabletInfo, wr.ActionTimeout())
}

func commandDemoteMaster(ctx context.Context, wr *wrangler.Wrangler, subFlags *flag.FlagSet, args []string) error {
	if err := subFlags.Parse(args); err != nil {
		return err
	}
	if subFlags.NArg() != 1 {
		return fmt.Errorf("action DemoteMaster requires <tablet alias>")
	}
	tabletAlias, err := topoproto.ParseTabletAlias(subFlags.Arg(0))
	if err != nil {
		return err
	}
	tabletInfo, err := wr.TopoServer().GetTablet(ctx, tabletAlias)
	if err != nil {
		return err
	}
	_, err = wr.TabletManagerClient().DemoteMaster(ctx, tabletInfo.Tablet)
	return err
}

// executeFetchLoop loops over the provided insertChannel
// and sends the commands to the provided tablet.
func executeFetchLoop(wr *wrangler.Wrangler, ti *topo.TabletInfo, insertChannel chan string, abort chan struct{}) error {
	for {
		select {
		case cmd, ok := <-insertChannel:
			if !ok {
				// no more to read, we're done
				return nil
			}
			cmd = "INSERT INTO `" + ti.DbName() + "`." + cmd
			_, err := wr.TabletManagerClient().ExecuteFetch(ti, cmd, 0, false, true, 30*time.Second)
			if err != nil {
				return fmt.Errorf("ExecuteFetch failed: %v", err)
			}
		case <-abort:
			// FIXME(alainjobart): note this select case
			// could be starved here, and we might miss
			// the abort in some corner cases.
			return nil
		}
	}
}

// runSqlCommands will send the sql commands to the remote tablet.
func runSqlCommands(wr *wrangler.Wrangler, ti *topo.TabletInfo, commands []string, abort chan struct{}) error {
	for _, command := range commands {
		command, err := fillStringTemplate(command, map[string]string{"DatabaseName": ti.DbName()})
		if err != nil {
			return fmt.Errorf("fillStringTemplate failed: %v", err)
		}

		_, err = wr.TabletManagerClient().ExecuteFetch(ti, command, 0, false, true, 30*time.Second)
		if err != nil {
			return err
		}

		// check on abort
		select {
		case <-abort:
			return nil
		default:
			break
		}
	}

	return nil
}

// FindChunks returns an array of chunks to use for splitting up a table
// into multiple data chunks. It only works for tables with a primary key
// (and the primary key first column is an integer type).
// The array will always look like:
// "", "value1", "value2", ""
// A non-split tablet will just return:
// "", ""
func FindChunks(ctx context.Context, wr *wrangler.Wrangler, ti *topo.TabletInfo, td *myproto.TableDefinition, minTableSizeForSplit uint64, sourceReaderCount int) ([]string, error) {
	result := []string{"", ""}

	// eliminate a few cases we don't split tables for
	if len(td.PrimaryKeyColumns) == 0 {
		// no primary key, what can we do?
		return result, nil
	}
	if td.DataLength < minTableSizeForSplit {
		// table is too small to split up
		return result, nil
	}

	// get the min and max of the leading column of the primary key
	query := fmt.Sprintf("SELECT MIN(%v), MAX(%v) FROM %v.%v", td.PrimaryKeyColumns[0], td.PrimaryKeyColumns[0], ti.DbName(), td.Name)
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	qr, err := wr.TabletManagerClient().ExecuteFetchAsApp(shortCtx, ti, query, 1, true)
	cancel()
	if err != nil {
		return nil, fmt.Errorf("ExecuteFetchAsApp: %v", err)
	}
	if len(qr.Rows) != 1 {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot get min and max", td.Name)
		return result, nil
	}
	if qr.Rows[0][0].IsNull() || qr.Rows[0][1].IsNull() {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, min or max is NULL: %v %v", td.Name, qr.Rows[0][0], qr.Rows[0][1])
		return result, nil
	}
	switch qr.Fields[0].Type {
	case mproto.VT_TINY, mproto.VT_SHORT, mproto.VT_LONG, mproto.VT_LONGLONG, mproto.VT_INT24:
		minNumeric := sqltypes.MakeNumeric(qr.Rows[0][0].Raw())
		maxNumeric := sqltypes.MakeNumeric(qr.Rows[0][1].Raw())
		if (qr.Fields[0].Flags & mproto.VT_UNSIGNED_FLAG) == 0 {
			// signed values, use int64
			min, err := minNumeric.ParseInt64()
			if err != nil {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
				return result, nil
			}
			max, err := maxNumeric.ParseInt64()
			if err != nil {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
				return result, nil
			}
			interval := (max - min) / int64(sourceReaderCount)
			if interval == 0 {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
				return result, nil
			}

			result = make([]string, sourceReaderCount+1)
			result[0] = ""
			result[sourceReaderCount] = ""
			for i := int64(1); i < int64(sourceReaderCount); i++ {
				result[i] = fmt.Sprintf("%v", min+interval*i)
			}
			return result, nil
		}

		// unsigned values, use uint64
		min, err := minNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
			return result, nil
		}
		max, err := maxNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
			return result, nil
		}
		interval := (max - min) / uint64(sourceReaderCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
			return result, nil
		}

		result = make([]string, sourceReaderCount+1)
		result[0] = ""
		result[sourceReaderCount] = ""
		for i := uint64(1); i < uint64(sourceReaderCount); i++ {
			result[i] = fmt.Sprintf("%v", min+interval*i)
		}
		return result, nil

	case mproto.VT_FLOAT, mproto.VT_DOUBLE:
		min, err := strconv.ParseFloat(qr.Rows[0][0].String(), 64)
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, qr.Rows[0][0], err)
			return result, nil
		}
		max, err := strconv.ParseFloat(qr.Rows[0][1].String(), 64)
		if err != nil {
//.........这里部分代码省略.........

// executeFetchWithRetries will attempt to run ExecuteFetch for a single command, with a reasonably small timeout.
// If will keep retrying the ExecuteFetch (for a finite but longer duration) if it fails due to a timeout or a
// retriable application error.
//
// executeFetchWithRetries will also re-resolve the topology after errors, to be resistant to a reparent.
// It takes in a tablet record that it will initially attempt to write to, and will return the final tablet
// record that it used.
func executeFetchWithRetries(ctx context.Context, wr *wrangler.Wrangler, ti *topo.TabletInfo, r Resolver, shard string, command string) (*topo.TabletInfo, error) {
	retryDuration := 2 * time.Hour
	// We should keep retrying up until the retryCtx runs out
	retryCtx, retryCancel := context.WithTimeout(ctx, retryDuration)
	defer retryCancel()
	// Is this current attempt a retry of a previous attempt?
	isRetry := false
	for {
		tryCtx, cancel := context.WithTimeout(retryCtx, 2*time.Minute)
		_, err := wr.TabletManagerClient().ExecuteFetchAsApp(tryCtx, ti, command, 0, false)
		cancel()
		if err == nil {
			// success!
			return ti, nil
		}
		// If the ExecuteFetch call failed because of an application error, we will try to figure out why.
		// We need to extract the MySQL error number, and will attempt to retry if we think the error is recoverable.
		match := errExtract.FindStringSubmatch(err.Error())
		var errNo string
		if len(match) == 2 {
			errNo = match[1]
		}
		switch {
		case wr.TabletManagerClient().IsTimeoutError(err):
			wr.Logger().Warningf("ExecuteFetch failed on %v; will retry because it was a timeout error: %v", ti, err)
			statsRetryCounters.Add("TimeoutError", 1)
		case errNo == "1290":
			wr.Logger().Warningf("ExecuteFetch failed on %v; will reresolve and retry because it's due to a MySQL read-only error: %v", ti, err)
			statsRetryCounters.Add("ReadOnly", 1)
		case errNo == "2002" || errNo == "2006":
			wr.Logger().Warningf("ExecuteFetch failed on %v; will reresolve and retry because it's due to a MySQL connection error: %v", ti, err)
			statsRetryCounters.Add("ConnectionError", 1)
		case errNo == "1062":
			if !isRetry {
				return ti, fmt.Errorf("ExecuteFetch failed on %v on the first attempt; not retrying as this is not a recoverable error: %v", ti, err)
			}
			wr.Logger().Infof("ExecuteFetch failed on %v with a duplicate entry error; marking this as a success, because of the likelihood that this query has already succeeded before being retried: %v", ti, err)
			return ti, nil
		default:
			// Unknown error
			return ti, err
		}
		t := time.NewTimer(*executeFetchRetryTime)
		// don't leak memory if the timer isn't triggered
		defer t.Stop()

		select {
		case <-retryCtx.Done():
			if retryCtx.Err() == context.DeadlineExceeded {
				return ti, fmt.Errorf("failed to connect to destination tablet %v after retrying for %v", ti, retryDuration)
			}
			return ti, fmt.Errorf("interrupted while trying to run %v on tablet %v", command, ti)
		case <-t.C:
			// Re-resolve and retry 30s after the failure
			err = r.ResolveDestinationMasters(ctx)
			if err != nil {
				return ti, fmt.Errorf("unable to re-resolve masters for ExecuteFetch, due to: %v", err)
			}
			ti, err = r.GetDestinationMaster(shard)
			if err != nil {
				// At this point, we probably don't have a valid tablet record to return
				return nil, fmt.Errorf("unable to run ExecuteFetch due to: %v", err)
			}
		}
		isRetry = true
	}
}

// generateChunks returns an array of chunks to use for splitting up a table
// into multiple data chunks. It only works for tables with a primary key
// whose first column is a numeric type.
func generateChunks(ctx context.Context, wr *wrangler.Wrangler, tablet *topodatapb.Tablet, td *tabletmanagerdatapb.TableDefinition, chunkCount, minRowsPerChunk int) ([]chunk, error) {
	if len(td.PrimaryKeyColumns) == 0 {
		// No explicit primary key. Cannot chunk the rows then.
		wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks because it has no primary key columns. This will reduce the performance of the clone.", td.Name)
		return singleCompleteChunk, nil
	}
	if td.RowCount < 2*uint64(minRowsPerChunk) {
		// The automatic adjustment of "chunkCount" based on "minRowsPerChunk"
		// below would set "chunkCount" to less than 2 i.e. 1 or 0 chunks.
		// In practice in this case there should be exactly one chunk.
		// Return early in this case and notice the user about this.
		wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks because it has only %d rows.", td.Name, td.RowCount)
		return singleCompleteChunk, nil
	}
	if chunkCount == 1 {
		return singleCompleteChunk, nil
	}

	// Get the MIN and MAX of the leading column of the primary key.
	query := fmt.Sprintf("SELECT MIN(%v), MAX(%v) FROM %v.%v", escape(td.PrimaryKeyColumns[0]), escape(td.PrimaryKeyColumns[0]), escape(topoproto.TabletDbName(tablet)), escape(td.Name))
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	qr, err := wr.TabletManagerClient().ExecuteFetchAsApp(shortCtx, tablet, true, []byte(query), 1)
	cancel()
	if err != nil {
		return nil, fmt.Errorf("Cannot determine MIN and MAX of the first primary key column. ExecuteFetchAsApp: %v", err)
	}
	if len(qr.Rows) != 1 {
		return nil, fmt.Errorf("Cannot determine MIN and MAX of the first primary key column. Zero rows were returned for the following query: %v", query)
	}

	result := sqltypes.Proto3ToResult(qr)
	min := result.Rows[0][0].ToNative()
	max := result.Rows[0][1].ToNative()

	if min == nil || max == nil {
		wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks, min or max is NULL: %v", td.Name, qr.Rows[0])
		return singleCompleteChunk, nil
	}

	// Determine the average number of rows per chunk for the given chunkCount.
	avgRowsPerChunk := td.RowCount / uint64(chunkCount)
	if avgRowsPerChunk < uint64(minRowsPerChunk) {
		// Reduce the chunkCount to fulfill minRowsPerChunk.
		newChunkCount := td.RowCount / uint64(minRowsPerChunk)
		wr.Logger().Infof("table=%v: Reducing the number of chunks from the default %d to %d to make sure that each chunk has at least %d rows.", td.Name, chunkCount, newChunkCount, minRowsPerChunk)
		chunkCount = int(newChunkCount)
	}

	// TODO(mberlin): Write a unit test for this part of the function.
	var interval interface{}
	chunks := make([]chunk, chunkCount)
	switch min := min.(type) {
	case int64:
		max := max.(int64)
		interval = (max - min) / int64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}
	case uint64:
		max := max.(uint64)
		interval = (max - min) / uint64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}
	case float64:
		max := max.(float64)
		interval = (max - min) / float64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}
	default:
		wr.Logger().Infof("table=%v: Not splitting the table into multiple chunks, primary key not numeric.", td.Name)
		return singleCompleteChunk, nil
	}

	// Create chunks.
	start := min
	for i := 0; i < chunkCount; i++ {
		end := add(start, interval)
		chunk, err := toChunk(start, end, i+1, chunkCount)
		if err != nil {
			return nil, err
		}
		chunks[i] = chunk
		start = end
	}

	// Clear out the MIN and MAX on the first and last chunk respectively
	// because other shards might have smaller or higher values than the one we
	// looked at.
	chunks[0].start = sqltypes.NULL
	chunks[chunkCount-1].end = sqltypes.NULL
	return chunks, nil
}

// generateChunks returns an array of chunks to use for splitting up a table
// into multiple data chunks. It only works for tables with a primary key
// whose first column is a numeric type.
func generateChunks(ctx context.Context, wr *wrangler.Wrangler, tablet *topodatapb.Tablet, td *tabletmanagerdatapb.TableDefinition, minTableSizeForSplit uint64, chunkCount int) ([]chunk, error) {
	if len(td.PrimaryKeyColumns) == 0 {
		// No explicit primary key. Cannot chunk the rows then.
		return singleCompleteChunk, nil
	}
	if td.DataLength < minTableSizeForSplit {
		// Table is too small to split up.
		return singleCompleteChunk, nil
	}
	if chunkCount == 1 {
		return singleCompleteChunk, nil
	}

	// Get the MIN and MAX of the leading column of the primary key.
	query := fmt.Sprintf("SELECT MIN(%v), MAX(%v) FROM %v.%v", td.PrimaryKeyColumns[0], td.PrimaryKeyColumns[0], topoproto.TabletDbName(tablet), td.Name)
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	qr, err := wr.TabletManagerClient().ExecuteFetchAsApp(shortCtx, tablet, true, []byte(query), 1)
	cancel()
	if err != nil {
		return nil, fmt.Errorf("Cannot determine MIN and MAX of the first primary key column. ExecuteFetchAsApp: %v", err)
	}
	if len(qr.Rows) != 1 {
		return nil, fmt.Errorf("Cannot determine MIN and MAX of the first primary key column. Zero rows were returned for the following query: %v", query)
	}

	result := sqltypes.Proto3ToResult(qr)
	min := result.Rows[0][0].ToNative()
	max := result.Rows[0][1].ToNative()

	if min == nil || max == nil {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, min or max is NULL: %v", td.Name, qr.Rows[0])
		return singleCompleteChunk, nil
	}

	// TODO(mberlin): Write a unit test for this part of the function.
	chunks := make([]chunk, chunkCount)
	switch min := min.(type) {
	case int64:
		max := max.(int64)
		interval := (max - min) / int64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}

		start := min
		for i := 0; i < chunkCount; i++ {
			end := start + interval
			chunk, err := toChunk(start, end)
			if err != nil {
				return nil, err
			}
			chunks[i] = chunk
			start = end
		}
	case uint64:
		max := max.(uint64)
		interval := (max - min) / uint64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}

		start := min
		for i := 0; i < chunkCount; i++ {
			end := start + interval
			chunk, err := toChunk(start, end)
			if err != nil {
				return nil, err
			}
			chunks[i] = chunk
			start = end
		}
	case float64:
		max := max.(float64)
		interval := (max - min) / float64(chunkCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v to %v", td.Name, min, max)
			return singleCompleteChunk, nil
		}

		start := min
		for i := 0; i < chunkCount; i++ {
			end := start + interval
			chunk, err := toChunk(start, end)
			if err != nil {
				return nil, err
			}
			chunks[i] = chunk
			start = end
		}
	default:
		wr.Logger().Infof("Not splitting table %v into multiple chunks, primary key not numeric.", td.Name)
		return singleCompleteChunk, nil
	}

	// Clear out the MIN and MAX on the first and last chunk respectively
//.........这里部分代码省略.........

// FindChunks returns an array of chunks to use for splitting up a table
// into multiple data chunks. It only works for tables with a primary key
// (and the primary key first column is an integer type).
// The array will always look like:
// "", "value1", "value2", ""
// A non-split tablet will just return:
// "", ""
func FindChunks(ctx context.Context, wr *wrangler.Wrangler, ti *topo.TabletInfo, td *tabletmanagerdatapb.TableDefinition, minTableSizeForSplit uint64, sourceReaderCount int) ([]string, error) {
	result := []string{"", ""}

	// eliminate a few cases we don't split tables for
	if len(td.PrimaryKeyColumns) == 0 {
		// no primary key, what can we do?
		return result, nil
	}
	if td.DataLength < minTableSizeForSplit {
		// table is too small to split up
		return result, nil
	}

	// get the min and max of the leading column of the primary key
	query := fmt.Sprintf("SELECT MIN(%v), MAX(%v) FROM %v.%v", td.PrimaryKeyColumns[0], td.PrimaryKeyColumns[0], ti.DbName(), td.Name)
	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
	qr, err := wr.TabletManagerClient().ExecuteFetchAsApp(shortCtx, ti, query, 1, true)
	cancel()
	if err != nil {
		return nil, fmt.Errorf("ExecuteFetchAsApp: %v", err)
	}
	if len(qr.Rows) != 1 {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot get min and max", td.Name)
		return result, nil
	}

	// FIXME(alainjobart) this code is a bit clunky. I'd like to
	// convert the first row into an array of Values, and then
	// see which type they are and go from there. Can only happen after
	// Value has a full type.
	l0 := qr.Rows[0].Lengths[0]
	l1 := qr.Rows[0].Lengths[1]
	if l0 < 0 || l1 < 0 {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, min or max is NULL: %v", td.Name, qr.Rows[0])
		return result, nil
	}
	minValue := qr.Rows[0].Values[:l0]
	maxValue := qr.Rows[0].Values[l0 : l0+l1]
	switch {
	case sqltypes.IsSigned(qr.Fields[0].Type):
		minNumeric := sqltypes.MakeNumeric(minValue)
		maxNumeric := sqltypes.MakeNumeric(maxValue)
		min, err := minNumeric.ParseInt64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
			return result, nil
		}
		max, err := maxNumeric.ParseInt64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
			return result, nil
		}
		interval := (max - min) / int64(sourceReaderCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
			return result, nil
		}

		result = make([]string, sourceReaderCount+1)
		result[0] = ""
		result[sourceReaderCount] = ""
		for i := int64(1); i < int64(sourceReaderCount); i++ {
			result[i] = fmt.Sprintf("%v", min+interval*i)
		}
		return result, nil

	case sqltypes.IsUnsigned(qr.Fields[0].Type):
		minNumeric := sqltypes.MakeNumeric(minValue)
		maxNumeric := sqltypes.MakeNumeric(maxValue)
		min, err := minNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
			return result, nil
		}
		max, err := maxNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
			return result, nil
		}
		interval := (max - min) / uint64(sourceReaderCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
			return result, nil
		}

		result = make([]string, sourceReaderCount+1)
		result[0] = ""
		result[sourceReaderCount] = ""
		for i := uint64(1); i < uint64(sourceReaderCount); i++ {
			result[i] = fmt.Sprintf("%v", min+interval*i)
		}
		return result, nil

//.........这里部分代码省略.........