-
Notifications
You must be signed in to change notification settings - Fork 288
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
scheduler(ticdc): split span by region written keys (#8496)
ref #7720
- Loading branch information
Showing
21 changed files
with
681 additions
and
33 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,150 @@ | ||
| // 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, | ||
| // See the License for the specific language governing permissions and | ||
| // limitations under the License. | ||
|
|
||
| package keyspan | ||
|
|
||
| import ( | ||
| "context" | ||
| "encoding/hex" | ||
|
|
||
| "github.com/pingcap/log" | ||
| "github.com/pingcap/tiflow/cdc/model" | ||
| "github.com/pingcap/tiflow/cdc/processor/tablepb" | ||
| "github.com/pingcap/tiflow/pkg/config" | ||
| "github.com/pingcap/tiflow/pkg/pdutil" | ||
| "go.uber.org/zap" | ||
| ) | ||
|
|
||
| type writeSplitter struct { | ||
| changefeedID model.ChangeFeedID | ||
| pdAPIClient pdutil.PDAPIClient | ||
| } | ||
|
|
||
| func newWriteSplitter( | ||
| changefeedID model.ChangeFeedID, pdAPIClient pdutil.PDAPIClient, | ||
| ) *writeSplitter { | ||
| return &writeSplitter{ | ||
| changefeedID: changefeedID, | ||
| pdAPIClient: pdAPIClient, | ||
| } | ||
| } | ||
|
|
||
| func (m *writeSplitter) split( | ||
| ctx context.Context, span tablepb.Span, totalCaptures int, | ||
| config *config.ChangefeedSchedulerConfig, | ||
| ) []tablepb.Span { | ||
| if config.WriteKeyThreshold == 0 { | ||
| return nil | ||
| } | ||
| regions, err := m.pdAPIClient.ScanRegions(ctx, span) | ||
| if err != nil { | ||
| // Skip split. | ||
| return nil | ||
| } | ||
| if totalCaptures <= 1 { | ||
| return []tablepb.Span{span} | ||
| } | ||
| info := splitRegionsByWrittenKeys(span.TableID, regions, config.WriteKeyThreshold, totalCaptures) | ||
| log.Info("schedulerv3: split span by written keys", | ||
| zap.Ints("counts", info.Counts), | ||
| zap.Ints("weights", info.Weights), | ||
| zap.String("span", span.String())) | ||
| return info.Spans | ||
| } | ||
|
|
||
| type splitRegionsInfo struct { | ||
| Counts []int | ||
| Weights []int | ||
| Spans []tablepb.Span | ||
| } | ||
|
|
||
| // splitRegionsByWrittenKeys returns a slice of regions that evenly split the range by write keys. | ||
| func splitRegionsByWrittenKeys( | ||
| tableID model.TableID, regions []pdutil.RegionInfo, writeKeyThreshold int, pages int, | ||
| ) *splitRegionsInfo { | ||
| decodeKey := func(hexkey string) []byte { | ||
| key, _ := hex.DecodeString(hexkey) | ||
| return key | ||
| } | ||
| totalWriteNormalized := uint64(0) | ||
| totalWrite := totalWriteNormalized | ||
| for i := range regions { | ||
| totalWrite += regions[i].WrittenKeys | ||
| // Override 0 to 1 to reflect the baseline cost of a region. | ||
| // Also it makes split evenly when there is no write. | ||
| regions[i].WrittenKeys++ | ||
| totalWriteNormalized += regions[i].WrittenKeys | ||
| } | ||
| if totalWrite < uint64(writeKeyThreshold) { | ||
| return &splitRegionsInfo{ | ||
| Counts: []int{len(regions)}, | ||
| Weights: []int{int(totalWriteNormalized)}, | ||
| Spans: []tablepb.Span{{ | ||
| TableID: tableID, | ||
| StartKey: tablepb.Key(decodeKey(regions[0].StartKey)), | ||
| EndKey: tablepb.Key(decodeKey(regions[len(regions)-1].EndKey)), | ||
| }}, | ||
| } | ||
| } | ||
|
|
||
| writtenKeysPerPage := totalWriteNormalized / uint64(pages) | ||
| counts := make([]int, 0, pages) | ||
| weights := make([]int, 0, pages) | ||
| spans := make([]tablepb.Span, 0, pages) | ||
| accWrittenKeys, pageWrittenKeys := uint64(0), uint64(0) | ||
| pageStartIdx, pageLastIdx := 0, 0 | ||
| for i := 1; i < pages; i++ { | ||
| for idx := pageStartIdx; idx < len(regions); idx++ { | ||
| restPages := pages - i | ||
| restRegions := len(regions) - idx | ||
| pageLastIdx = idx | ||
| currentWrittenKeys := regions[idx].WrittenKeys | ||
| if (idx > pageStartIdx) && | ||
| ((restPages >= restRegions) || | ||
| (accWrittenKeys+currentWrittenKeys > writtenKeysPerPage)) { | ||
| spans = append(spans, tablepb.Span{ | ||
| TableID: tableID, | ||
| StartKey: tablepb.Key(decodeKey(regions[pageStartIdx].StartKey)), | ||
| EndKey: tablepb.Key(decodeKey(regions[idx-1].EndKey)), | ||
| }) | ||
| counts = append(counts, idx-pageStartIdx) | ||
| weights = append(weights, int(pageWrittenKeys)) | ||
| pageWrittenKeys = 0 | ||
| pageStartIdx = idx | ||
| writtenKeysPerPage = (totalWriteNormalized - accWrittenKeys) / uint64(restPages) | ||
| accWrittenKeys = 0 | ||
| break | ||
| } | ||
| pageWrittenKeys += currentWrittenKeys | ||
| accWrittenKeys += currentWrittenKeys | ||
| } | ||
| } | ||
| // Always end with the last region. | ||
| spans = append(spans, tablepb.Span{ | ||
| TableID: tableID, | ||
| StartKey: tablepb.Key(decodeKey(regions[pageLastIdx].StartKey)), | ||
| EndKey: tablepb.Key(decodeKey(regions[len(regions)-1].EndKey)), | ||
| }) | ||
| counts = append(counts, len(regions)-pageLastIdx) | ||
| pageWrittenKeys = 0 | ||
| for idx := pageLastIdx; idx < len(regions); idx++ { | ||
| pageWrittenKeys += regions[idx].WrittenKeys | ||
| } | ||
| weights = append(weights, int(pageWrittenKeys)) | ||
|
|
||
| return &splitRegionsInfo{ | ||
| Counts: counts, | ||
| Weights: weights, | ||
| Spans: spans, | ||
| } | ||
| } |
Oops, something went wrong.