Addressing some comments

Signed-off-by: Alan Protasio <[email protected]>

Author: alanprot

pkg/querier/blocks_store_queryable.go

@@ -578,11 +578,12 @@ func (q *blocksStoreQuerier) fetchSeriesFromStores(
 		reqStats      = stats.FromContext(ctx)
 	)
 	matchers, shardingInfo, err := querysharding.ExtractShardingInfo(matchers)
-	convertedMatchers := convertMatchersToLabelMatcher(matchers)
 
 	if err != nil {
 		return nil, nil, nil, 0, err
+
 	}
+	convertedMatchers := convertMatchersToLabelMatcher(matchers)
 
 	// Concurrently fetch series from all clients.
 	for c, blockIDs := range clients {

pkg/querier/tripperware/instantquery/InstantQueryMiddlewares.go renamed to pkg/querier/tripperware/instantquery/instant_query_middlewares.go

@@ -8,7 +8,7 @@ import (
 	"github.com/cortexproject/cortex/pkg/querier/tripperware"
 )
 
-// Config for query_range middleware chain.
+// Config for instant query middleware chain.
 type Config struct {
 	VerticalShardSize int `yaml:"vertical_shard_size"`
 }

pkg/querier/tripperware/shard_by_query.go renamed to pkg/querier/tripperware/shard_by.go

@@ -4,15 +4,17 @@ import (
 	"context"
 
 	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
 	"github.com/thanos-io/thanos/pkg/querysharding"
 	"github.com/thanos-io/thanos/pkg/store/storepb"
 
 	cquerysharding "github.com/cortexproject/cortex/pkg/querysharding"
+	util_log "github.com/cortexproject/cortex/pkg/util/log"
 )
 
 func ShardByMiddleware(logger log.Logger, limits Limits, merger Merger, numShards int) Middleware {
 	return MiddlewareFunc(func(next Handler) Handler {
-		return shardQueryByMiddleware{
+		return shardBy{
 			next:      next,
 			limits:    limits,
 			merger:    merger,
@@ -22,7 +24,7 @@ func ShardByMiddleware(logger log.Logger, limits Limits, merger Merger, numShard
 	})
 }
 
-type shardQueryByMiddleware struct {
+type shardBy struct {
 	next          Handler
 	limits        Limits
 	logger        log.Logger
@@ -31,17 +33,18 @@ type shardQueryByMiddleware struct {
 	numShards     int
 }
 
-func (s shardQueryByMiddleware) Do(ctx context.Context, r Request) (Response, error) {
+func (s shardBy) Do(ctx context.Context, r Request) (Response, error) {
+	logger := util_log.WithContext(ctx, s.logger)
 	analysis, err := s.queryAnalyzer.Analyze(r.GetQuery())
 	if err != nil {
-		return nil, err
+		level.Warn(logger).Log("msg", "error sharding query", "q", r.GetQuery(), "err", err)
 	}
 
-	if !analysis.IsShardable() {
+	if err != nil || !analysis.IsShardable() {
 		return s.next.Do(ctx, r)
 	}
 
-	reqs := s.shardQuery(r, analysis)
+	reqs := s.shardQuery(logger, r, analysis)
 
 	reqResps, err := DoRequests(ctx, s.next, reqs, s.limits)
 	if err != nil {
@@ -60,7 +63,7 @@ func (s shardQueryByMiddleware) Do(ctx context.Context, r Request) (Response, er
 	return response, nil
 }
 
-func (s shardQueryByMiddleware) shardQuery(r Request, analysis querysharding.QueryAnalysis) []Request {
+func (s shardBy) shardQuery(l log.Logger, r Request, analysis querysharding.QueryAnalysis) []Request {
 	reqs := make([]Request, s.numShards)
 	for i := 0; i < s.numShards; i++ {
 		q, err := cquerysharding.InjectShardingInfo(r.GetQuery(), &storepb.ShardInfo{
@@ -72,7 +75,7 @@ func (s shardQueryByMiddleware) shardQuery(r Request, analysis querysharding.Que
 		reqs[i] = r.WithQuery(q)
 
 		if err != nil {
-			s.logger.Log("error sharding query", "q", r.GetQuery())
+			level.Warn(l).Log("msg", "error sharding query", "q", r.GetQuery(), "err", err)
 			return []Request{r}
 		}
 	}

pkg/querier/tripperware/test_shard_by_query_utils.go

@@ -80,6 +80,10 @@ func TestQueryShardQuery(t *testing.T, instantQueryCodec Codec, shardedPrometheu
 / on ()
 http_requests_total`,
 		},
+		{
+			name:       "problematic query",
+			expression: `sum(a by(lanel)`,
+		},
 	}
 
 	shardableByLabels := []queries{

pkg/querysharding/util.go

@@ -29,12 +29,13 @@ func InjectShardingInfo(query string, shardInfo *storepb.ShardInfo) (string, err
 	if err != nil {
 		return "", err
 	}
+	eShardInfo := base64.StdEncoding.EncodeToString(b)
 	parser.Inspect(expr, func(n parser.Node, _ []parser.Node) error {
 		if selector, ok := n.(*parser.VectorSelector); ok {
 			selector.LabelMatchers = append(selector.LabelMatchers, &labels.Matcher{
 				Type:  labels.MatchEqual,
 				Name:  CortexShardByLabel,
-				Value: base64.StdEncoding.EncodeToString(b),
+				Value: eShardInfo,
 			})
 		}
 		return nil