milvus/internal/datacoord/segment_manager.go
congqixia f5451d12f3
Refactor datacoord allocator (#7226)
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>
2021-08-23 17:59:51 +08:00

498 lines
14 KiB
Go

// Copyright (C) 2019-2020 Zilliz. All rights reserved.
// 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 datacoord
import (
"context"
"fmt"
"sync"
"time"
"go.uber.org/zap"
"github.com/milvus-io/milvus/internal/log"
"github.com/milvus-io/milvus/internal/msgstream"
"github.com/milvus-io/milvus/internal/proto/commonpb"
"github.com/milvus-io/milvus/internal/proto/internalpb"
"github.com/milvus-io/milvus/internal/util/trace"
"github.com/milvus-io/milvus/internal/util/tsoutil"
"github.com/milvus-io/milvus/internal/proto/datapb"
)
const segmentMaxLifetime = 24 * time.Hour
// Manager manage segment related operations.
type Manager interface {
// AllocSegment allocate rows and record the allocation.
AllocSegment(ctx context.Context, collectionID, partitionID UniqueID, channelName string, requestRows int64) ([]*Allocation, error)
// DropSegment drop the segment from allocator.
DropSegment(ctx context.Context, segmentID UniqueID)
// SealAllSegments sealed all segmetns of collection with collectionID and return sealed segments
SealAllSegments(ctx context.Context, collectionID UniqueID) ([]UniqueID, error)
// GetFlushableSegments return flushable segment ids
GetFlushableSegments(ctx context.Context, channel string, ts Timestamp) ([]UniqueID, error)
// ExpireAllocations notify segment status to expire old allocations
ExpireAllocations(channel string, ts Timestamp) error
}
// allcation entry for segment Allocation record
type Allocation struct {
SegmentID UniqueID
NumOfRows int64
ExpireTime Timestamp
}
// SegmentManager handles segment related logic
type SegmentManager struct {
meta *meta
mu sync.RWMutex
allocator allocator
helper allocHelper
segments []UniqueID
estimatePolicy calUpperLimitPolicy
allocPolicy AllocatePolicy
segmentSealPolicies []segmentSealPolicy
channelSealPolicies []channelSealPolicy
flushPolicy flushPolicy
allocPool sync.Pool
}
type allocHelper struct {
afterCreateSegment func(segment *datapb.SegmentInfo) error
}
// allocOption allction option applies to `SegmentManager`
type allocOption interface {
apply(manager *SegmentManager)
}
// allocFunc function shortcut for allocOption
type allocFunc func(manager *SegmentManager)
// implement allocOption
func (f allocFunc) apply(manager *SegmentManager) {
f(manager)
}
// get allocOption with allocHelper setting
func withAllocHelper(helper allocHelper) allocOption {
return allocFunc(func(manager *SegmentManager) { manager.helper = helper })
}
// get default allocHelper, which does nothing
func defaultAllocHelper() allocHelper {
return allocHelper{
afterCreateSegment: func(segment *datapb.SegmentInfo) error { return nil },
}
}
// get allocOption with estimatePolicy
func withCalUpperLimitPolicy(policy calUpperLimitPolicy) allocOption {
return allocFunc(func(manager *SegmentManager) { manager.estimatePolicy = policy })
}
// get allocOption with allocPolicy
func withAllocPolicy(policy AllocatePolicy) allocOption {
return allocFunc(func(manager *SegmentManager) { manager.allocPolicy = policy })
}
// get allocOption with segmentSealPolicies
func withSegmentSealPolices(policies ...segmentSealPolicy) allocOption {
return allocFunc(func(manager *SegmentManager) {
// do override instead of append, to override default options
manager.segmentSealPolicies = policies
})
}
// get allocOption with channelSealPolicies
func withChannelSealPolices(policies ...channelSealPolicy) allocOption {
return allocFunc(func(manager *SegmentManager) {
// do override instead of append, to override default options
manager.channelSealPolicies = policies
})
}
// get allocOption with flushPolicy
func withFlushPolicy(policy flushPolicy) allocOption {
return allocFunc(func(manager *SegmentManager) { manager.flushPolicy = policy })
}
func defaultCalUpperLimitPolicy() calUpperLimitPolicy {
return calBySchemaPolicy
}
func defaultAlocatePolicy() AllocatePolicy {
return AllocatePolicyV1
}
func defaultSegmentSealPolicy() []segmentSealPolicy {
return []segmentSealPolicy{
sealByLifetimePolicy(segmentMaxLifetime),
getSegmentCapacityPolicy(Params.SegmentSealProportion),
}
}
func defaultFlushPolicy() flushPolicy {
return flushPolicyV1
}
// newSegmentManager should be the only way to retrieve SegmentManager
func newSegmentManager(meta *meta, allocator allocator, opts ...allocOption) *SegmentManager {
manager := &SegmentManager{
meta: meta,
allocator: allocator,
helper: defaultAllocHelper(),
segments: make([]UniqueID, 0),
estimatePolicy: defaultCalUpperLimitPolicy(),
allocPolicy: defaultAlocatePolicy(),
segmentSealPolicies: defaultSegmentSealPolicy(), // default only segment size policy
channelSealPolicies: []channelSealPolicy{}, // no default channel seal policy
flushPolicy: defaultFlushPolicy(),
allocPool: sync.Pool{
New: func() interface{} {
return &Allocation{}
},
},
}
for _, opt := range opts {
opt.apply(manager)
}
manager.loadSegmentsFromMeta()
return manager
}
// loadSegmentsFromMeta generate corresponding segment status for each segment from meta
func (s *SegmentManager) loadSegmentsFromMeta() {
segments := s.meta.GetUnFlushedSegments()
segmentsID := make([]UniqueID, 0, len(segments))
for _, segment := range segments {
segmentsID = append(segmentsID, segment.GetID())
}
s.segments = segmentsID
}
// getAllocation unified way to retrieve allocation struct
func (s *SegmentManager) getAllocation(numOfRows int64) *Allocation {
v := s.allocPool.Get()
if v == nil {
return &Allocation{
NumOfRows: numOfRows,
}
}
a, ok := v.(*Allocation)
if !ok {
a = &Allocation{}
}
a.NumOfRows = numOfRows
return a
}
// putAllocation put allocation for recycling
func (s *SegmentManager) putAllocation(a *Allocation) {
s.allocPool.Put(a)
}
// AllocSegment allocate segment per request collcation, partication, channel and rows
func (s *SegmentManager) AllocSegment(ctx context.Context, collectionID UniqueID,
partitionID UniqueID, channelName string, requestRows int64) ([]*Allocation, error) {
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
s.mu.Lock()
defer s.mu.Unlock()
// filter segments
segments := make([]*SegmentInfo, 0)
for _, segmentID := range s.segments {
segment := s.meta.GetSegment(segmentID)
if segment == nil {
log.Warn("Failed to get seginfo from meta", zap.Int64("id", segmentID))
continue
}
if segment.State == commonpb.SegmentState_Sealed || segment.CollectionID != collectionID ||
segment.PartitionID != partitionID || segment.InsertChannel != channelName {
continue
}
segments = append(segments, segment)
}
// apply allocate policy
maxCountPerSegment, err := s.estimateMaxNumOfRows(collectionID)
if err != nil {
return nil, err
}
newSegmentAllocations, existedSegmentAllocations := s.allocPolicy(segments,
requestRows, int64(maxCountPerSegment))
// create new segments and add allocations
expireTs, err := s.genExpireTs(ctx)
if err != nil {
return nil, err
}
for _, allocation := range newSegmentAllocations {
segment, err := s.openNewSegment(ctx, collectionID, partitionID, channelName)
if err != nil {
return nil, err
}
allocation.ExpireTime = expireTs
allocation.SegmentID = segment.GetID()
if err := s.meta.AddAllocation(segment.GetID(), allocation); err != nil {
return nil, err
}
}
for _, allocation := range existedSegmentAllocations {
allocation.ExpireTime = expireTs
if err := s.meta.AddAllocation(allocation.SegmentID, allocation); err != nil {
return nil, err
}
}
allocations := append(newSegmentAllocations, existedSegmentAllocations...)
return allocations, nil
}
func (s *SegmentManager) genExpireTs(ctx context.Context) (Timestamp, error) {
ts, err := s.allocator.allocTimestamp(ctx)
if err != nil {
return 0, err
}
physicalTs, logicalTs := tsoutil.ParseTS(ts)
expirePhysicalTs := physicalTs.Add(time.Duration(Params.SegAssignmentExpiration) * time.Millisecond)
expireTs := tsoutil.ComposeTS(expirePhysicalTs.UnixNano()/int64(time.Millisecond), int64(logicalTs))
return expireTs, nil
}
func (s *SegmentManager) openNewSegment(ctx context.Context, collectionID UniqueID, partitionID UniqueID, channelName string) (*SegmentInfo, error) {
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
id, err := s.allocator.allocID(ctx)
if err != nil {
return nil, err
}
maxNumOfRows, err := s.estimateMaxNumOfRows(collectionID)
if err != nil {
return nil, err
}
segmentInfo := &datapb.SegmentInfo{
ID: id,
CollectionID: collectionID,
PartitionID: partitionID,
InsertChannel: channelName,
NumOfRows: 0,
State: commonpb.SegmentState_Growing,
MaxRowNum: int64(maxNumOfRows),
LastExpireTime: 0,
StartPosition: &internalpb.MsgPosition{
ChannelName: channelName,
MsgID: []byte{},
MsgGroup: "",
Timestamp: 0,
},
}
segment := NewSegmentInfo(segmentInfo)
if err := s.meta.AddSegment(segment); err != nil {
return nil, err
}
s.segments = append(s.segments, id)
log.Debug("datacoord: estimateTotalRows: ",
zap.Int64("CollectionID", segmentInfo.CollectionID),
zap.Int64("SegmentID", segmentInfo.ID),
zap.Int("Rows", maxNumOfRows),
zap.String("Channel", segmentInfo.InsertChannel))
s.helper.afterCreateSegment(segmentInfo)
return segment, nil
}
func (s *SegmentManager) estimateMaxNumOfRows(collectionID UniqueID) (int, error) {
collMeta := s.meta.GetCollection(collectionID)
if collMeta == nil {
return -1, fmt.Errorf("Failed to get collection %d", collectionID)
}
return s.estimatePolicy(collMeta.Schema)
}
func (s *SegmentManager) DropSegment(ctx context.Context, segmentID UniqueID) {
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
s.mu.Lock()
defer s.mu.Unlock()
for i, id := range s.segments {
if id == segmentID {
s.segments = append(s.segments[:i], s.segments[i+1:]...)
break
}
}
segment := s.meta.GetSegment(segmentID)
if segment == nil {
log.Warn("failed to get segment", zap.Int64("id", segmentID))
}
s.meta.SetAllocations(segmentID, []*Allocation{})
for _, allocation := range segment.allocations {
s.putAllocation(allocation)
}
}
func (s *SegmentManager) SealAllSegments(ctx context.Context, collectionID UniqueID) ([]UniqueID, error) {
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
s.mu.Lock()
defer s.mu.Unlock()
ret := make([]UniqueID, 0)
for _, id := range s.segments {
info := s.meta.GetSegment(id)
if info == nil {
log.Warn("Failed to get seg info from meta", zap.Int64("id", id))
continue
}
if info.CollectionID != collectionID {
continue
}
if info.State == commonpb.SegmentState_Sealed {
ret = append(ret, id)
continue
}
if err := s.meta.SetState(id, commonpb.SegmentState_Sealed); err != nil {
return nil, err
}
ret = append(ret, id)
}
return ret, nil
}
func (s *SegmentManager) GetFlushableSegments(ctx context.Context, channel string,
t Timestamp) ([]UniqueID, error) {
s.mu.Lock()
defer s.mu.Unlock()
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
if err := s.tryToSealSegment(t, channel); err != nil {
return nil, err
}
ret := make([]UniqueID, 0, len(s.segments))
for _, id := range s.segments {
info := s.meta.GetSegment(id)
if info == nil || info.InsertChannel != channel {
continue
}
if s.flushPolicy(info, t) {
ret = append(ret, id)
}
}
return ret, nil
}
// ExpireAllocations notify segment status to expire old allocations
func (s *SegmentManager) ExpireAllocations(channel string, ts Timestamp) error {
s.mu.Lock()
defer s.mu.Unlock()
for _, id := range s.segments {
segment := s.meta.GetSegment(id)
if segment == nil || segment.InsertChannel != channel {
continue
}
allocations := make([]*Allocation, 0, len(segment.allocations))
for i := 0; i < len(segment.allocations); i++ {
if segment.allocations[i].ExpireTime <= ts {
a := segment.allocations[i]
s.putAllocation(a)
} else {
allocations = append(allocations, segment.allocations[i])
}
}
s.meta.SetAllocations(segment.GetID(), allocations)
}
return nil
}
// tryToSealSegment applies segment & channel seal policies
func (s *SegmentManager) tryToSealSegment(ts Timestamp, channel string) error {
channelInfo := make(map[string][]*SegmentInfo)
for _, id := range s.segments {
info := s.meta.GetSegment(id)
if info == nil || info.InsertChannel != channel {
continue
}
channelInfo[info.InsertChannel] = append(channelInfo[info.InsertChannel], info)
if info.State == commonpb.SegmentState_Sealed {
continue
}
// change shouldSeal to segment seal policy logic
for _, policy := range s.segmentSealPolicies {
if policy(info, ts) {
if err := s.meta.SetState(id, commonpb.SegmentState_Sealed); err != nil {
return err
}
break
}
}
}
for channel, segmentInfos := range channelInfo {
for _, policy := range s.channelSealPolicies {
vs := policy(channel, segmentInfos, ts)
for _, info := range vs {
if info.State == commonpb.SegmentState_Sealed {
continue
}
if err := s.meta.SetState(info.GetID(), commonpb.SegmentState_Sealed); err != nil {
return err
}
}
}
}
return nil
}
// only for test
func (s *SegmentManager) SealSegment(ctx context.Context, segmentID UniqueID) error {
sp, _ := trace.StartSpanFromContext(ctx)
defer sp.Finish()
s.mu.Lock()
defer s.mu.Unlock()
if err := s.meta.SetState(segmentID, commonpb.SegmentState_Sealed); err != nil {
return err
}
return nil
}
func createNewSegmentHelper(stream msgstream.MsgStream) allocHelper {
h := allocHelper{}
h.afterCreateSegment = func(segment *datapb.SegmentInfo) error {
infoMsg := &msgstream.SegmentInfoMsg{
BaseMsg: msgstream.BaseMsg{
HashValues: []uint32{0},
},
SegmentMsg: datapb.SegmentMsg{
Base: &commonpb.MsgBase{
MsgType: commonpb.MsgType_SegmentInfo,
MsgID: 0,
Timestamp: 0,
SourceID: Params.NodeID,
},
Segment: segment,
},
}
msgPack := &msgstream.MsgPack{
Msgs: []msgstream.TsMsg{infoMsg},
}
if err := stream.Produce(msgPack); err != nil {
return err
}
return nil
}
return h
}