wei liu 54619eaa2c
feat: Implement partial result support on node down (#42009)
issue: https://github.com/milvus-io/milvus/issues/41690
This commit implements partial search result functionality when query
nodes go down, improving system availability during node failures. The
changes include:

- Enhanced load balancing in proxy (lb_policy.go) to handle node
failures with retry support
- Added partial search result capability in querynode delegator and
distribution logic
- Implemented tests for various partial result scenarios when nodes go
down
- Added metrics to track partial search results in querynode_metrics.go
- Updated parameter configuration to support partial result required
data ratio
- Replaced old partial_search_test.go with more comprehensive
partial_result_on_node_down_test.go
- Updated proto definitions and improved retry logic

These changes improve query resilience by returning partial results to
users when some query nodes are unavailable, ensuring that queries don't
completely fail when a portion of data remains accessible.

---------

Signed-off-by: Wei Liu <wei.liu@zilliz.com>
2025-05-28 00:12:28 +08:00

565 lines
19 KiB
Go

// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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 querynodev2
import (
"context"
"fmt"
"strconv"
"github.com/samber/lo"
"go.opentelemetry.io/otel/trace"
"go.uber.org/zap"
"github.com/milvus-io/milvus-proto/go-api/v2/commonpb"
"github.com/milvus-io/milvus/internal/querynodev2/delegator"
"github.com/milvus-io/milvus/internal/querynodev2/segments"
"github.com/milvus-io/milvus/internal/querynodev2/tasks"
"github.com/milvus-io/milvus/internal/util/reduce"
"github.com/milvus-io/milvus/internal/util/streamrpc"
"github.com/milvus-io/milvus/pkg/v2/log"
"github.com/milvus-io/milvus/pkg/v2/metrics"
"github.com/milvus-io/milvus/pkg/v2/proto/datapb"
"github.com/milvus-io/milvus/pkg/v2/proto/internalpb"
"github.com/milvus-io/milvus/pkg/v2/proto/querypb"
"github.com/milvus-io/milvus/pkg/v2/util/funcutil"
"github.com/milvus-io/milvus/pkg/v2/util/merr"
"github.com/milvus-io/milvus/pkg/v2/util/paramtable"
"github.com/milvus-io/milvus/pkg/v2/util/timerecord"
)
func loadL0Segments(ctx context.Context, delegator delegator.ShardDelegator, req *querypb.WatchDmChannelsRequest) error {
l0Segments := make([]*querypb.SegmentLoadInfo, 0)
for _, channel := range req.GetInfos() {
for _, segmentID := range channel.GetLevelZeroSegmentIds() {
segmentInfo, ok := req.GetSegmentInfos()[segmentID]
if !ok ||
segmentInfo.GetLevel() != datapb.SegmentLevel_L0 {
continue
}
l0Segments = append(l0Segments, &querypb.SegmentLoadInfo{
SegmentID: segmentID,
PartitionID: segmentInfo.PartitionID,
CollectionID: segmentInfo.CollectionID,
BinlogPaths: segmentInfo.Binlogs,
NumOfRows: segmentInfo.NumOfRows,
Statslogs: segmentInfo.Statslogs,
Deltalogs: segmentInfo.Deltalogs,
Bm25Logs: segmentInfo.Bm25Statslogs,
InsertChannel: segmentInfo.InsertChannel,
StartPosition: segmentInfo.GetStartPosition(),
Level: segmentInfo.GetLevel(),
})
}
}
return delegator.LoadL0(ctx, l0Segments, req.GetVersion())
}
func loadGrowingSegments(ctx context.Context, delegator delegator.ShardDelegator, req *querypb.WatchDmChannelsRequest) error {
// load growing segments
growingSegments := make([]*querypb.SegmentLoadInfo, 0, len(req.Infos))
for _, info := range req.Infos {
for _, segmentID := range info.GetUnflushedSegmentIds() {
// unFlushed segment may not have binLogs, skip loading
segmentInfo := req.GetSegmentInfos()[segmentID]
if segmentInfo == nil {
log.Warn("an unflushed segment is not found in segment infos", zap.Int64("segmentID", segmentID))
continue
}
if len(segmentInfo.GetBinlogs()) > 0 {
growingSegments = append(growingSegments, &querypb.SegmentLoadInfo{
SegmentID: segmentInfo.ID,
Level: segmentInfo.GetLevel(),
PartitionID: segmentInfo.PartitionID,
CollectionID: segmentInfo.CollectionID,
BinlogPaths: segmentInfo.Binlogs,
NumOfRows: segmentInfo.NumOfRows,
Statslogs: segmentInfo.Statslogs,
Deltalogs: segmentInfo.Deltalogs,
Bm25Logs: segmentInfo.Bm25Statslogs,
InsertChannel: segmentInfo.InsertChannel,
StartPosition: segmentInfo.GetStartPosition(),
StorageVersion: segmentInfo.GetStorageVersion(),
})
} else {
log.Info("skip segment which binlog is empty", zap.Int64("segmentID", segmentInfo.ID))
}
}
}
return delegator.LoadGrowing(ctx, growingSegments, req.GetVersion())
}
func (node *QueryNode) loadDeltaLogs(ctx context.Context, req *querypb.LoadSegmentsRequest) *commonpb.Status {
log := log.Ctx(ctx).With(
zap.Int64("collectionID", req.GetCollectionID()),
)
var finalErr error
for _, info := range req.GetInfos() {
segment := node.manager.Segment.GetSealed(info.GetSegmentID())
if segment == nil {
continue
}
err := node.loader.LoadDeltaLogs(ctx, segment, info.GetDeltalogs())
if err != nil {
if finalErr == nil {
finalErr = err
}
continue
}
// try to update segment version after load delta logs
node.manager.Segment.UpdateBy(segments.IncreaseVersion(req.GetVersion()), segments.WithType(segments.SegmentTypeSealed), segments.WithID(info.GetSegmentID()))
}
if finalErr != nil {
log.Warn("failed to load delta logs", zap.Error(finalErr))
return merr.Status(finalErr)
}
return merr.Success()
}
func (node *QueryNode) loadIndex(ctx context.Context, req *querypb.LoadSegmentsRequest) *commonpb.Status {
log := log.Ctx(ctx).With(
zap.Int64("collectionID", req.GetCollectionID()),
zap.Int64s("segmentIDs", lo.Map(req.GetInfos(), func(info *querypb.SegmentLoadInfo, _ int) int64 { return info.GetSegmentID() })),
)
status := merr.Success()
log.Info("start to load index")
for _, info := range req.GetInfos() {
log := log.With(zap.Int64("segmentID", info.GetSegmentID()))
segment := node.manager.Segment.GetSealed(info.GetSegmentID())
if segment == nil {
log.Warn("segment not found for load index operation")
continue
}
localSegment, ok := segment.(*segments.LocalSegment)
if !ok {
log.Warn("segment not local for load index opeartion")
continue
}
if localSegment.IsLazyLoad() {
localSegment.SetLoadInfo(info)
localSegment.SetNeedUpdatedVersion(req.GetVersion())
node.manager.DiskCache.MarkItemNeedReload(ctx, localSegment.ID())
return nil
}
err := node.loader.LoadIndex(ctx, localSegment, info, req.Version)
if err != nil {
log.Warn("failed to load index", zap.Error(err))
status = merr.Status(err)
break
}
}
return status
}
func (node *QueryNode) loadStats(ctx context.Context, req *querypb.LoadSegmentsRequest) *commonpb.Status {
log := log.Ctx(ctx).With(
zap.Int64("collectionID", req.GetCollectionID()),
zap.Int64s("segmentIDs", lo.Map(req.GetInfos(), func(info *querypb.SegmentLoadInfo, _ int) int64 { return info.GetSegmentID() })),
)
status := merr.Success()
log.Info("start to load stats")
for _, info := range req.GetInfos() {
log := log.With(zap.Int64("segmentID", info.GetSegmentID()))
segment := node.manager.Segment.GetSealed(info.GetSegmentID())
if segment == nil {
log.Warn("segment not found for load stats operation")
continue
}
localSegment, ok := segment.(*segments.LocalSegment)
if !ok {
log.Warn("segment not local for load stats opeartion")
continue
}
if localSegment.IsLazyLoad() {
localSegment.SetLoadInfo(info)
localSegment.SetNeedUpdatedVersion(req.GetVersion())
node.manager.DiskCache.MarkItemNeedReload(ctx, localSegment.ID())
return nil
}
err := node.loader.LoadJSONIndex(ctx, localSegment, info)
if err != nil {
log.Warn("failed to load stats", zap.Error(err))
status = merr.Status(err)
break
}
}
return status
}
func (node *QueryNode) queryChannel(ctx context.Context, req *querypb.QueryRequest, channel string) (*internalpb.RetrieveResults, error) {
msgID := req.Req.Base.GetMsgID()
traceID := trace.SpanFromContext(ctx).SpanContext().TraceID()
log := log.Ctx(ctx).With(
zap.Int64("msgID", msgID),
zap.Int64("collectionID", req.GetReq().GetCollectionID()),
zap.String("channel", channel),
zap.String("scope", req.GetScope().String()),
)
var err error
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.TotalLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
defer func() {
if err != nil {
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.FailLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
}
metrics.QueryNodePartialResultCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
}()
log.Debug("start do query with channel",
zap.Int64s("segmentIDs", req.GetSegmentIDs()),
)
// add cancel when error occurs
queryCtx, cancel := context.WithCancel(ctx)
defer cancel()
// From Proxy
tr := timerecord.NewTimeRecorder("queryDelegator")
// get delegator
sd, ok := node.delegators.Get(channel)
if !ok {
err := merr.WrapErrChannelNotFound(channel)
log.Warn("Query failed, failed to get shard delegator for query", zap.Error(err))
return nil, err
}
// do query
results, err := sd.Query(queryCtx, req)
if err != nil {
log.Warn("failed to query on delegator", zap.Error(err))
return nil, err
}
// reduce result
tr.CtxElapse(ctx, fmt.Sprintf("start reduce query result, traceID = %s, vChannel = %s, segmentIDs = %v",
traceID,
channel,
req.GetSegmentIDs(),
))
if !node.manager.Collection.Ref(req.Req.GetCollectionID(), 1) {
err := merr.WrapErrCollectionNotFound(req.Req.GetCollectionID())
log.Warn("Query failed, failed to get collection", zap.Error(err))
return nil, err
}
collection := node.manager.Collection.Get(req.Req.GetCollectionID())
defer func() {
node.manager.Collection.Unref(req.GetReq().GetCollectionID(), 1)
}()
reducer := segments.CreateInternalReducer(req, collection.Schema())
resp, err := reducer.Reduce(ctx, results)
if err != nil {
return nil, err
}
tr.CtxElapse(ctx, fmt.Sprintf("do query with channel done , vChannel = %s, segmentIDs = %v",
channel,
req.GetSegmentIDs(),
))
latency := tr.ElapseSpan()
metrics.QueryNodeSQReqLatency.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.Leader).Observe(float64(latency.Milliseconds()))
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.SuccessLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
return resp, nil
}
func (node *QueryNode) queryChannelStream(ctx context.Context, req *querypb.QueryRequest, channel string, srv streamrpc.QueryStreamServer) error {
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.TotalLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
msgID := req.Req.Base.GetMsgID()
log := log.Ctx(ctx).With(
zap.Int64("msgID", msgID),
zap.Int64("collectionID", req.GetReq().GetCollectionID()),
zap.String("channel", channel),
zap.String("scope", req.GetScope().String()),
)
var err error
defer func() {
if err != nil {
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.QueryLabel, metrics.FailLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
}
}()
log.Debug("start do streaming query with channel",
zap.Int64s("segmentIDs", req.GetSegmentIDs()),
)
// add cancel when error occurs
queryCtx, cancel := context.WithCancel(ctx)
defer cancel()
// From Proxy
tr := timerecord.NewTimeRecorder("queryDelegator")
// get delegator
sd, ok := node.delegators.Get(channel)
if !ok {
err := merr.WrapErrChannelNotFound(channel)
log.Warn("Query failed, failed to get query shard delegator", zap.Error(err))
return err
}
// do query
err = sd.QueryStream(queryCtx, req, srv)
if err != nil {
return err
}
tr.CtxElapse(ctx, fmt.Sprintf("do query with channel done , vChannel = %s, segmentIDs = %v",
channel,
req.GetSegmentIDs(),
))
return nil
}
func (node *QueryNode) queryStreamSegments(ctx context.Context, req *querypb.QueryRequest, srv streamrpc.QueryStreamServer) error {
log.Ctx(ctx).Debug("received query stream request",
zap.Int64s("outputFields", req.GetReq().GetOutputFieldsId()),
zap.Int64s("segmentIDs", req.GetSegmentIDs()),
zap.Uint64("guaranteeTimestamp", req.GetReq().GetGuaranteeTimestamp()),
zap.Uint64("mvccTimestamp", req.GetReq().GetMvccTimestamp()),
)
if !node.manager.Collection.Ref(req.Req.GetCollectionID(), 1) {
err := merr.WrapErrCollectionNotFound(req.Req.GetCollectionID())
log.Warn("Query stream segments failed, failed to get collection", zap.Error(err))
return err
}
collection := node.manager.Collection.Get(req.Req.GetCollectionID())
defer func() {
node.manager.Collection.Unref(req.GetReq().GetCollectionID(), 1)
}()
// Send task to scheduler and wait until it finished.
task := tasks.NewQueryStreamTask(ctx, collection, node.manager, req, srv,
paramtable.Get().QueryNodeCfg.QueryStreamBatchSize.GetAsInt(),
paramtable.Get().QueryNodeCfg.QueryStreamMaxBatchSize.GetAsInt())
if err := node.scheduler.Add(task); err != nil {
log.Ctx(ctx).Warn("failed to add query task into scheduler", zap.Error(err))
return err
}
err := task.Wait()
if err != nil {
log.Ctx(ctx).Warn("failed to execute task by node scheduler", zap.Error(err))
return err
}
return nil
}
func (node *QueryNode) searchChannel(ctx context.Context, req *querypb.SearchRequest, channel string) (*internalpb.SearchResults, error) {
log := log.Ctx(ctx).With(
zap.Int64("msgID", req.GetReq().GetBase().GetMsgID()),
zap.Int64("collectionID", req.Req.GetCollectionID()),
zap.String("channel", channel),
zap.String("scope", req.GetScope().String()),
zap.Int64("nq", req.GetReq().GetNq()),
)
traceID := trace.SpanFromContext(ctx).SpanContext().TraceID()
if err := node.lifetime.Add(merr.IsHealthy); err != nil {
return nil, err
}
defer node.lifetime.Done()
var err error
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.TotalLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
defer func() {
if err != nil {
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.FailLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
}
}()
log.Debug("start to search channel",
zap.Int64s("segmentIDs", req.GetSegmentIDs()),
)
searchCtx, cancel := context.WithCancel(ctx)
defer cancel()
// From Proxy
tr := timerecord.NewTimeRecorder("searchDelegator")
// get delegator
sd, ok := node.delegators.Get(channel)
if !ok {
err := merr.WrapErrChannelNotFound(channel)
log.Warn("Query failed, failed to get shard delegator for search", zap.Error(err))
return nil, err
}
// do search
results, err := sd.Search(searchCtx, req)
if err != nil {
log.Warn("failed to search on delegator", zap.Error(err))
return nil, err
}
// reduce result
tr.CtxElapse(ctx, fmt.Sprintf("start reduce query result, traceID = %s, vChannel = %s, segmentIDs = %v",
traceID,
channel,
req.GetSegmentIDs(),
))
resp, err := segments.ReduceSearchOnQueryNode(ctx, results,
reduce.NewReduceSearchResultInfo(req.GetReq().GetNq(),
req.GetReq().GetTopk()).WithMetricType(req.GetReq().GetMetricType()).WithGroupByField(req.GetReq().GetGroupByFieldId()).
WithGroupSize(req.GetReq().GetGroupSize()).WithAdvance(req.GetReq().GetIsAdvanced()))
if err != nil {
return nil, err
}
tr.CtxElapse(ctx, fmt.Sprintf("do search with channel done , vChannel = %s, segmentIDs = %v",
channel,
req.GetSegmentIDs(),
))
// update metric to prometheus
latency := tr.ElapseSpan()
metrics.QueryNodeSQReqLatency.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.Leader).Observe(float64(latency.Milliseconds()))
metrics.QueryNodeSQCount.WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.SuccessLabel, metrics.Leader, fmt.Sprint(req.GetReq().GetCollectionID())).Inc()
metrics.QueryNodeSearchNQ.WithLabelValues(fmt.Sprint(node.GetNodeID())).Observe(float64(req.Req.GetNq()))
metrics.QueryNodeSearchTopK.WithLabelValues(fmt.Sprint(node.GetNodeID())).Observe(float64(req.Req.GetTopk()))
return resp, nil
}
func (node *QueryNode) getChannelStatistics(ctx context.Context, req *querypb.GetStatisticsRequest, channel string) (*internalpb.GetStatisticsResponse, error) {
log := log.Ctx(ctx).With(
zap.Int64("collectionID", req.Req.GetCollectionID()),
zap.String("channel", channel),
zap.String("scope", req.GetScope().String()),
)
resp := &internalpb.GetStatisticsResponse{}
if req.GetFromShardLeader() {
var (
results []segments.SegmentStats
readSegments []segments.Segment
err error
)
switch req.GetScope() {
case querypb.DataScope_Historical:
results, readSegments, err = segments.StatisticsHistorical(ctx, node.manager, req.Req.GetCollectionID(), req.Req.GetPartitionIDs(), req.GetSegmentIDs())
case querypb.DataScope_Streaming:
results, readSegments, err = segments.StatisticStreaming(ctx, node.manager, req.Req.GetCollectionID(), req.Req.GetPartitionIDs(), req.GetSegmentIDs())
}
defer node.manager.Segment.Unpin(readSegments)
if err != nil {
log.Warn("get segments statistics failed", zap.Error(err))
return nil, err
}
return segmentStatsResponse(results), nil
}
sd, ok := node.delegators.Get(channel)
if !ok {
err := merr.WrapErrChannelNotFound(channel, "failed to get channel statistics")
log.Warn("GetStatistics failed, failed to get query shard delegator", zap.Error(err))
resp.Status = merr.Status(err)
return resp, nil
}
results, err := sd.GetStatistics(ctx, req)
if err != nil {
log.Warn("failed to get statistics from delegator", zap.Error(err))
resp.Status = merr.Status(err)
return resp, nil
}
resp, err = reduceStatisticResponse(results)
if err != nil {
log.Warn("failed to reduce channel statistics", zap.Error(err))
resp.Status = merr.Status(err)
return resp, nil
}
return resp, nil
}
func segmentStatsResponse(segStats []segments.SegmentStats) *internalpb.GetStatisticsResponse {
var totalRowNum int64
for _, stats := range segStats {
totalRowNum += stats.RowCount
}
resultMap := make(map[string]string)
resultMap["row_count"] = strconv.FormatInt(totalRowNum, 10)
ret := &internalpb.GetStatisticsResponse{
Status: merr.Success(),
Stats: funcutil.Map2KeyValuePair(resultMap),
}
return ret
}
func reduceStatisticResponse(results []*internalpb.GetStatisticsResponse) (*internalpb.GetStatisticsResponse, error) {
mergedResults := map[string]interface{}{
"row_count": int64(0),
}
fieldMethod := map[string]func(string) error{
"row_count": func(str string) error {
count, err := strconv.ParseInt(str, 10, 64)
if err != nil {
return err
}
mergedResults["row_count"] = mergedResults["row_count"].(int64) + count
return nil
},
}
for _, partialResult := range results {
for _, pair := range partialResult.Stats {
fn, ok := fieldMethod[pair.Key]
if !ok {
return nil, fmt.Errorf("unknown statistic field: %s", pair.Key)
}
if err := fn(pair.Value); err != nil {
return nil, err
}
}
}
stringMap := make(map[string]string)
for k, v := range mergedResults {
stringMap[k] = fmt.Sprint(v)
}
ret := &internalpb.GetStatisticsResponse{
Status: merr.Success(),
Stats: funcutil.Map2KeyValuePair(stringMap),
}
return ret, nil
}