Files
tidb/executor/importer/chunk_process.go

278 lines
7.2 KiB
Go

// Copyright 2023 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package importer
import (
"context"
"io"
"time"
"github.com/docker/go-units"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/br/pkg/lightning/backend"
"github.com/pingcap/tidb/br/pkg/lightning/backend/kv"
"github.com/pingcap/tidb/br/pkg/lightning/checkpoints"
"github.com/pingcap/tidb/br/pkg/lightning/common"
"github.com/pingcap/tidb/br/pkg/lightning/log"
"github.com/pingcap/tidb/br/pkg/lightning/mydump"
verify "github.com/pingcap/tidb/br/pkg/lightning/verification"
"github.com/pingcap/tidb/executor/asyncloaddata"
"github.com/pingcap/tidb/tablecodec"
"github.com/tikv/client-go/v2/tikv"
"go.uber.org/zap"
"golang.org/x/sync/errgroup"
)
// constants, make it a variable for test
var (
maxKVQueueSize = 32 // Cache at most this number of rows before blocking the encode loop
MinDeliverBytes uint64 = 96 * units.KiB // 96 KB (data + index). batch at least this amount of bytes to reduce number of messages
// see default for tikv-importer.max-kv-pairs
MinDeliverRowCnt = 4096
)
type deliveredRow struct {
kvs *kv.Pairs // if kvs is nil, this indicated we've got the last message.
// end offset in data file after encode this row.
offset int64
}
type deliverResult struct {
err error
}
type deliverKVBatch struct {
dataKVs kv.Pairs
indexKVs kv.Pairs
dataChecksum *verify.KVChecksum
indexChecksum *verify.KVChecksum
codec tikv.Codec
}
func newDeliverKVBatch(codec tikv.Codec) *deliverKVBatch {
return &deliverKVBatch{
dataChecksum: verify.NewKVChecksumWithKeyspace(codec),
indexChecksum: verify.NewKVChecksumWithKeyspace(codec),
codec: codec,
}
}
func (b *deliverKVBatch) reset() {
b.dataKVs.Clear()
b.indexKVs.Clear()
b.dataChecksum = verify.NewKVChecksumWithKeyspace(b.codec)
b.indexChecksum = verify.NewKVChecksumWithKeyspace(b.codec)
}
func (b *deliverKVBatch) size() uint64 {
return b.dataChecksum.SumSize() + b.indexChecksum.SumSize()
}
func (b *deliverKVBatch) add(kvs *kv.Pairs) {
for _, pair := range kvs.Pairs {
if tablecodec.IsRecordKey(pair.Key) {
b.dataKVs.Pairs = append(b.dataKVs.Pairs, pair)
b.dataChecksum.UpdateOne(pair)
} else {
b.indexKVs.Pairs = append(b.indexKVs.Pairs, pair)
b.indexChecksum.UpdateOne(pair)
}
}
// the related buf is shared, so we only need to set it into one of the kvs so it can be released
if kvs.BytesBuf != nil {
b.dataKVs.BytesBuf = kvs.BytesBuf
b.dataKVs.MemBuf = kvs.MemBuf
}
}
// chunkProcessor process data chunk, it encodes and writes KV to local disk.
type chunkProcessor struct {
parser mydump.Parser
chunkInfo *checkpoints.ChunkCheckpoint
logger *zap.Logger
kvsCh chan []deliveredRow
dataWriter backend.EngineWriter
indexWriter backend.EngineWriter
encoder kvEncoder
kvCodec tikv.Codec
progress *asyncloaddata.Progress
startOffset int64
}
func (p *chunkProcessor) process(ctx context.Context) (err error) {
task := log.BeginTask(p.logger, "process chunk")
defer func() {
task.End(zap.ErrorLevel, err)
}()
if err2 := p.initProgress(); err2 != nil {
return err2
}
group, gCtx := errgroup.WithContext(ctx)
group.Go(func() error {
return p.deliverLoop(gCtx)
})
group.Go(func() error {
return p.encodeLoop(gCtx)
})
return group.Wait()
}
func (p *chunkProcessor) initProgress() error {
// we might skip N rows or start from checkpoint
offset, err := p.parser.ScannedPos()
if err != nil {
return errors.Trace(err)
}
p.progress.EncodeFileSize.Add(offset)
p.startOffset = offset
return nil
}
func (p *chunkProcessor) encodeLoop(ctx context.Context) error {
defer close(p.kvsCh)
send := func(kvs []deliveredRow) error {
select {
case p.kvsCh <- kvs:
return nil
case <-ctx.Done():
return ctx.Err()
}
}
var err error
reachEOF := false
for !reachEOF {
var readDur, encodeDur time.Duration
canDeliver := false
rowBatch := make([]deliveredRow, 0, MinDeliverRowCnt)
var newOffset int64
var kvSize uint64
outLoop:
for !canDeliver {
readDurStart := time.Now()
err = p.parser.ReadRow()
// todo: we can implement a ScannedPos which don't return error, will change it later.
newOffset, _ = p.parser.ScannedPos()
switch errors.Cause(err) {
case nil:
case io.EOF:
reachEOF = true
break outLoop
default:
return common.ErrEncodeKV.Wrap(err).GenWithStackByArgs(p.chunkInfo.GetKey(), newOffset)
}
readDur += time.Since(readDurStart)
encodeDurStart := time.Now()
lastRow := p.parser.LastRow()
// sql -> kv
kvs, encodeErr := p.encoder.Encode(lastRow.Row, lastRow.RowID)
encodeDur += time.Since(encodeDurStart)
if encodeErr != nil {
// todo: record and ignore encode error if user set max-errors param
err = common.ErrEncodeKV.Wrap(encodeErr).GenWithStackByArgs(p.chunkInfo.GetKey(), newOffset)
}
p.parser.RecycleRow(lastRow)
if err != nil {
return err
}
p.progress.ReadRowCnt.Inc()
rowBatch = append(rowBatch, deliveredRow{kvs: kvs, offset: newOffset})
kvSize += kvs.Size()
// pebble cannot allow > 4.0G kv in one batch.
// we will meet pebble panic when import sql file and each kv has the size larger than 4G / maxKvPairsCnt.
// so add this check.
if kvSize >= MinDeliverBytes || len(rowBatch) >= MinDeliverRowCnt {
canDeliver = true
kvSize = 0
}
}
if len(rowBatch) > 0 {
if err = send(rowBatch); err != nil {
return err
}
}
}
return nil
}
func (p *chunkProcessor) deliverLoop(ctx context.Context) error {
kvBatch := newDeliverKVBatch(p.kvCodec)
prevOffset, currOffset := p.startOffset, p.startOffset
for {
outer:
for kvBatch.size() < MinDeliverBytes {
select {
case kvPacket, ok := <-p.kvsCh:
if !ok {
break outer
}
for _, row := range kvPacket {
kvBatch.add(row.kvs)
currOffset = row.offset
}
case <-ctx.Done():
return ctx.Err()
}
}
if kvBatch.size() == 0 {
break
}
err := func() error {
// todo: disk quota related code from lightning, removed temporary
if err := p.dataWriter.AppendRows(ctx, nil, &kvBatch.dataKVs); err != nil {
if !common.IsContextCanceledError(err) {
p.logger.Error("write to data engine failed", log.ShortError(err))
}
return errors.Trace(err)
}
if err := p.indexWriter.AppendRows(ctx, nil, &kvBatch.indexKVs); err != nil {
if !common.IsContextCanceledError(err) {
p.logger.Error("write to index engine failed", log.ShortError(err))
}
return errors.Trace(err)
}
return nil
}()
if err != nil {
return err
}
p.progress.EncodeFileSize.Add(currOffset - prevOffset)
prevOffset = currOffset
p.chunkInfo.Checksum.Add(kvBatch.dataChecksum)
p.chunkInfo.Checksum.Add(kvBatch.indexChecksum)
kvBatch.reset()
}
return nil
}