milvus/internal/querycoord/query_coord.go
2021-11-05 16:00:55 +08:00

430 lines
13 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 querycoord
import (
"context"
"errors"
"fmt"
"math/rand"
"strconv"
"sync"
"sync/atomic"
"time"
"github.com/golang/protobuf/proto"
"go.etcd.io/etcd/api/v3/mvccpb"
"go.uber.org/zap"
"github.com/milvus-io/milvus/internal/allocator"
etcdkv "github.com/milvus-io/milvus/internal/kv/etcd"
"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/proto/querypb"
"github.com/milvus-io/milvus/internal/types"
"github.com/milvus-io/milvus/internal/util/metricsinfo"
"github.com/milvus-io/milvus/internal/util/retry"
"github.com/milvus-io/milvus/internal/util/sessionutil"
"github.com/milvus-io/milvus/internal/util/tsoutil"
"github.com/milvus-io/milvus/internal/util/typeutil"
)
const (
handoffSegmentPrefix = "querycoord-handoff"
)
// Timestamp is an alias for the Int64 type
type Timestamp = typeutil.Timestamp
type queryChannelInfo struct {
requestChannel string
responseChannel string
}
// QueryCoord is the coordinator of queryNodes
type QueryCoord struct {
loopCtx context.Context
loopCancel context.CancelFunc
loopWg sync.WaitGroup
kvClient *etcdkv.EtcdKV
initOnce sync.Once
queryCoordID uint64
meta Meta
cluster Cluster
newNodeFn newQueryNodeFn
scheduler *TaskScheduler
idAllocator func() (UniqueID, error)
metricsCacheManager *metricsinfo.MetricsCacheManager
dataCoordClient types.DataCoord
rootCoordClient types.RootCoord
session *sessionutil.Session
eventChan <-chan *sessionutil.SessionEvent
stateCode atomic.Value
enableGrpc bool
msFactory msgstream.Factory
}
// Register register query service at etcd
func (qc *QueryCoord) Register() error {
log.Debug("query coord session info", zap.String("metaPath", Params.MetaRootPath), zap.Strings("etcdEndPoints", Params.EtcdEndpoints), zap.String("address", Params.Address))
qc.session = sessionutil.NewSession(qc.loopCtx, Params.MetaRootPath, Params.EtcdEndpoints)
qc.session.Init(typeutil.QueryCoordRole, Params.Address, true)
Params.NodeID = uint64(qc.session.ServerID)
Params.SetLogger(typeutil.UniqueID(-1))
return nil
}
// Init function initializes the queryCoord's meta, cluster, etcdKV and task scheduler
func (qc *QueryCoord) Init() error {
log.Debug("query coordinator start init")
//connect etcd
connectEtcdFn := func() error {
etcdKV, err := etcdkv.NewEtcdKV(Params.EtcdEndpoints, Params.MetaRootPath)
if err != nil {
return err
}
qc.kvClient = etcdKV
return nil
}
var initError error = nil
qc.initOnce.Do(func() {
log.Debug("query coordinator try to connect etcd")
initError = retry.Do(qc.loopCtx, connectEtcdFn, retry.Attempts(300))
if initError != nil {
log.Debug("query coordinator try to connect etcd failed", zap.Error(initError))
return
}
log.Debug("query coordinator try to connect etcd success")
// init id allocator
var idAllocatorKV *etcdkv.EtcdKV
idAllocatorKV, initError = tsoutil.NewTSOKVBase(Params.EtcdEndpoints, Params.KvRootPath, "queryCoordTaskID")
if initError != nil {
return
}
idAllocator := allocator.NewGlobalIDAllocator("idTimestamp", idAllocatorKV)
initError = idAllocator.Initialize()
if initError != nil {
log.Debug("query coordinator idAllocator initialize failed", zap.Error(initError))
return
}
qc.idAllocator = func() (UniqueID, error) {
return idAllocator.AllocOne()
}
// init meta
qc.meta, initError = newMeta(qc.loopCtx, qc.kvClient, qc.msFactory, qc.idAllocator)
if initError != nil {
log.Error("query coordinator init meta failed", zap.Error(initError))
return
}
// init cluster
qc.cluster, initError = newQueryNodeCluster(qc.loopCtx, qc.meta, qc.kvClient, qc.newNodeFn, qc.session)
if initError != nil {
log.Error("query coordinator init cluster failed", zap.Error(initError))
return
}
// init task scheduler
qc.scheduler, initError = NewTaskScheduler(qc.loopCtx, qc.meta, qc.cluster, qc.kvClient, qc.rootCoordClient, qc.dataCoordClient, qc.idAllocator)
if initError != nil {
log.Error("query coordinator init task scheduler failed", zap.Error(initError))
return
}
qc.metricsCacheManager = metricsinfo.NewMetricsCacheManager()
})
return initError
}
// Start function starts the goroutines to watch the meta and node updates
func (qc *QueryCoord) Start() error {
m := map[string]interface{}{
"PulsarAddress": Params.PulsarAddress,
"ReceiveBufSize": 1024,
"PulsarBufSize": 1024}
err := qc.msFactory.SetParams(m)
if err != nil {
return err
}
qc.scheduler.Start()
log.Debug("start scheduler ...")
Params.CreatedTime = time.Now()
Params.UpdatedTime = time.Now()
qc.UpdateStateCode(internalpb.StateCode_Healthy)
qc.loopWg.Add(1)
go qc.watchNodeLoop()
qc.loopWg.Add(1)
go qc.watchHandoffSegmentLoop()
go qc.session.LivenessCheck(qc.loopCtx, func() {
log.Error("Query Coord disconnected from etcd, process will exit", zap.Int64("Server Id", qc.session.ServerID))
if err := qc.Stop(); err != nil {
log.Fatal("failed to stop server", zap.Error(err))
}
})
return nil
}
// Stop function stops watching the meta and node updates
func (qc *QueryCoord) Stop() error {
qc.scheduler.Close()
log.Debug("close scheduler ...")
qc.loopCancel()
qc.UpdateStateCode(internalpb.StateCode_Abnormal)
qc.loopWg.Wait()
return nil
}
// UpdateStateCode updates the status of the coord, including healthy, unhealthy
func (qc *QueryCoord) UpdateStateCode(code internalpb.StateCode) {
qc.stateCode.Store(code)
}
// NewQueryCoord creates a QueryCoord object.
func NewQueryCoord(ctx context.Context, factory msgstream.Factory) (*QueryCoord, error) {
rand.Seed(time.Now().UnixNano())
queryChannels := make([]*queryChannelInfo, 0)
channelID := len(queryChannels)
searchPrefix := Params.SearchChannelPrefix
searchResultPrefix := Params.SearchResultChannelPrefix
allocatedQueryChannel := searchPrefix + "-" + strconv.FormatInt(int64(channelID), 10)
allocatedQueryResultChannel := searchResultPrefix + "-" + strconv.FormatInt(int64(channelID), 10)
queryChannels = append(queryChannels, &queryChannelInfo{
requestChannel: allocatedQueryChannel,
responseChannel: allocatedQueryResultChannel,
})
ctx1, cancel := context.WithCancel(ctx)
service := &QueryCoord{
loopCtx: ctx1,
loopCancel: cancel,
msFactory: factory,
newNodeFn: newQueryNode,
}
service.UpdateStateCode(internalpb.StateCode_Abnormal)
log.Debug("query coordinator", zap.Any("queryChannels", queryChannels))
return service, nil
}
// SetRootCoord sets root coordinator's client
func (qc *QueryCoord) SetRootCoord(rootCoord types.RootCoord) error {
if rootCoord == nil {
return errors.New("null root coordinator interface")
}
qc.rootCoordClient = rootCoord
return nil
}
// SetDataCoord sets data coordinator's client
func (qc *QueryCoord) SetDataCoord(dataCoord types.DataCoord) error {
if dataCoord == nil {
return errors.New("null data coordinator interface")
}
qc.dataCoordClient = dataCoord
return nil
}
func (qc *QueryCoord) watchNodeLoop() {
ctx, cancel := context.WithCancel(qc.loopCtx)
defer cancel()
defer qc.loopWg.Done()
log.Debug("query coordinator start watch node loop")
offlineNodes, err := qc.cluster.offlineNodes()
if err == nil {
offlineNodeIDs := make([]int64, 0)
for id := range offlineNodes {
offlineNodeIDs = append(offlineNodeIDs, id)
}
loadBalanceSegment := &querypb.LoadBalanceRequest{
Base: &commonpb.MsgBase{
MsgType: commonpb.MsgType_LoadBalanceSegments,
SourceID: qc.session.ServerID,
},
SourceNodeIDs: offlineNodeIDs,
}
baseTask := newBaseTask(qc.loopCtx, querypb.TriggerCondition_nodeDown)
loadBalanceTask := &loadBalanceTask{
baseTask: baseTask,
LoadBalanceRequest: loadBalanceSegment,
rootCoord: qc.rootCoordClient,
dataCoord: qc.dataCoordClient,
cluster: qc.cluster,
meta: qc.meta,
}
//TODO::deal enqueue error
qc.scheduler.Enqueue(loadBalanceTask)
log.Debug("start a loadBalance task", zap.Any("task", loadBalanceTask))
}
qc.eventChan = qc.session.WatchServices(typeutil.QueryNodeRole, qc.cluster.getSessionVersion()+1)
for {
select {
case <-ctx.Done():
return
case event, ok := <-qc.eventChan:
if !ok {
return
}
switch event.EventType {
case sessionutil.SessionAddEvent:
serverID := event.Session.ServerID
log.Debug("start add a queryNode to cluster", zap.Any("nodeID", serverID))
err := qc.cluster.registerNode(ctx, event.Session, serverID, disConnect)
if err != nil {
log.Error("query node failed to register", zap.Int64("nodeID", serverID), zap.String("error info", err.Error()))
}
qc.metricsCacheManager.InvalidateSystemInfoMetrics()
case sessionutil.SessionDelEvent:
serverID := event.Session.ServerID
log.Debug("get a del event after queryNode down", zap.Int64("nodeID", serverID))
nodeExist := qc.cluster.hasNode(serverID)
if !nodeExist {
log.Error("queryNode not exist", zap.Int64("nodeID", serverID))
continue
}
qc.cluster.stopNode(serverID)
loadBalanceSegment := &querypb.LoadBalanceRequest{
Base: &commonpb.MsgBase{
MsgType: commonpb.MsgType_LoadBalanceSegments,
SourceID: qc.session.ServerID,
},
SourceNodeIDs: []int64{serverID},
BalanceReason: querypb.TriggerCondition_nodeDown,
}
baseTask := newBaseTask(qc.loopCtx, querypb.TriggerCondition_nodeDown)
loadBalanceTask := &loadBalanceTask{
baseTask: baseTask,
LoadBalanceRequest: loadBalanceSegment,
rootCoord: qc.rootCoordClient,
dataCoord: qc.dataCoordClient,
cluster: qc.cluster,
meta: qc.meta,
}
qc.metricsCacheManager.InvalidateSystemInfoMetrics()
//TODO:: deal enqueue error
qc.scheduler.Enqueue(loadBalanceTask)
log.Debug("start a loadBalance task", zap.Any("task", loadBalanceTask))
}
}
}
}
func (qc *QueryCoord) watchHandoffSegmentLoop() {
ctx, cancel := context.WithCancel(qc.loopCtx)
defer cancel()
defer qc.loopWg.Done()
log.Debug("query coordinator start watch segment loop")
// TODO:: recover handoff task when coord down
watchChan := qc.kvClient.WatchWithPrefix(handoffSegmentPrefix)
for {
select {
case <-ctx.Done():
return
case resp := <-watchChan:
for _, event := range resp.Events {
segmentInfo := &querypb.SegmentInfo{}
err := proto.Unmarshal(event.Kv.Value, segmentInfo)
if err != nil {
log.Error("watchHandoffSegmentLoop: unmarshal failed", zap.Any("error", err.Error()))
continue
}
switch event.Type {
case mvccpb.PUT:
collectionID := segmentInfo.CollectionID
partitionID := segmentInfo.PartitionID
segmentID := segmentInfo.SegmentID
if Params.AutoHandoff {
log.Debug("watchHandoffSegmentLoop: handoff segment received",
zap.Any("collectionID", collectionID),
zap.Any("partitionID", partitionID),
zap.Any("segmentID", segmentID),
zap.Any("channel", segmentInfo.ChannelID),
)
baseTask := newBaseTask(qc.loopCtx, querypb.TriggerCondition_handoff)
handoffReq := &querypb.HandoffSegmentsRequest{
Base: &commonpb.MsgBase{
MsgType: commonpb.MsgType_HandoffSegments,
},
SegmentInfos: []*querypb.SegmentInfo{segmentInfo},
}
handoffTask := &handoffTask{
baseTask: baseTask,
HandoffSegmentsRequest: handoffReq,
dataCoord: qc.dataCoordClient,
cluster: qc.cluster,
meta: qc.meta,
}
err = qc.scheduler.Enqueue(handoffTask)
if err != nil {
log.Error("watchHandoffSegmentLoop: handoffTask enqueue failed", zap.Error(err))
break
}
go func() {
err := handoffTask.waitToFinish()
if err != nil {
log.Error("watchHandoffSegmentLoop: handoffTask failed", zap.Error(err))
}
}()
log.Debug("watchHandoffSegmentLoop: handoffTask completed",
zap.Any("collectionID", collectionID),
zap.Any("partitionID", partitionID),
zap.Any("segmentID", segmentID),
zap.Any("channel", segmentInfo.ChannelID),
)
}
buildQuerySegmentPath := fmt.Sprintf("%s/%d/%d/%d", handoffSegmentPrefix, collectionID, partitionID, segmentID)
err = qc.kvClient.Remove(buildQuerySegmentPath)
if err != nil {
log.Error("watchHandoffSegmentLoop: remove handoff segment from etcd failed", zap.Error(err))
}
default:
// do nothing
}
}
}
}
}