Add flag for limiting OTLP request size

CHANGELOG.md

@@ -15,6 +15,7 @@
 * [FEATURE] Ruler: Minimize chances of missed rule group evaluations that can occur due to OOM kills, bad underlying nodes, or due to an unhealthy ruler that appears in the ring as healthy. This feature is enabled via `-ruler.enable-ha-evaluation` flag. #6129
 * [FEATURE] Store Gateway: Add an in-memory chunk cache. #6245
 * [FEATURE] Chunk Cache: Support multi level cache and add metrics. #6249
+* [ENHANCEMENT] OTLP: Add `-distributor.otlp-max-recv-msg-size` flag to limit OTLP request size in bytes. #6333
 * [ENHANCEMENT] S3 Bucket Client: Add a list objects version configs to configure list api object version. #6280
 * [ENHANCEMENT] OpenStack Swift: Add application credential configs for Openstack swift object storage backend. #6255
 * [ENHANCEMENT] Query Frontend: Add new query stats metrics `cortex_query_samples_scanned_total` and `cortex_query_peak_samples` to track scannedSamples and peakSample per user. #6228

docs/configuration/config-file-reference.md

@@ -2562,6 +2562,10 @@ ha_tracker:
 # CLI flag: -distributor.max-recv-msg-size
 [max_recv_msg_size: <int> | default = 104857600]
 
+# Maximum OTLP request size in bytes that the Distributor can accept.
+# CLI flag: -distributor.otlp-max-recv-msg-size
+[otlp_max_recv_msg_size: <int> | default = 104857600]
+
 # Timeout for downstream ingesters.
 # CLI flag: -distributor.remote-timeout
 [remote_timeout: <duration> | default = 2s]

pkg/api/api.go

@@ -278,7 +278,7 @@ func (a *API) RegisterDistributor(d *distributor.Distributor, pushConfig distrib
 	distributorpb.RegisterDistributorServer(a.server.GRPC, d)
 
 	a.RegisterRoute("/api/v1/push", push.Handler(pushConfig.MaxRecvMsgSize, a.sourceIPs, a.cfg.wrapDistributorPush(d)), true, "POST")
-	a.RegisterRoute("/api/v1/otlp/v1/metrics", push.OTLPHandler(overrides, pushConfig.OTLPConfig, a.sourceIPs, a.cfg.wrapDistributorPush(d)), true, "POST")
+	a.RegisterRoute("/api/v1/otlp/v1/metrics", push.OTLPHandler(pushConfig.OTLPMaxRecvMsgSize, overrides, pushConfig.OTLPConfig, a.sourceIPs, a.cfg.wrapDistributorPush(d)), true, "POST")
 
 	a.indexPage.AddLink(SectionAdminEndpoints, "/distributor/ring", "Distributor Ring Status")
 	a.indexPage.AddLink(SectionAdminEndpoints, "/distributor/all_user_stats", "Usage Statistics")

pkg/distributor/distributor.go

@@ -135,9 +135,10 @@ type Config struct {
 
 	HATrackerConfig HATrackerConfig `yaml:"ha_tracker"`
 
-	MaxRecvMsgSize  int           `yaml:"max_recv_msg_size"`
-	RemoteTimeout   time.Duration `yaml:"remote_timeout"`
-	ExtraQueryDelay time.Duration `yaml:"extra_queue_delay"`
+	MaxRecvMsgSize     int           `yaml:"max_recv_msg_size"`
+	OTLPMaxRecvMsgSize int           `yaml:"otlp_max_recv_msg_size"`
+	RemoteTimeout      time.Duration `yaml:"remote_timeout"`
+	ExtraQueryDelay    time.Duration `yaml:"extra_queue_delay"`
 
 	ShardingStrategy         string `yaml:"sharding_strategy"`
 	ShardByAllLabels         bool   `yaml:"shard_by_all_labels"`
@@ -186,6 +187,7 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	cfg.DistributorRing.RegisterFlags(f)
 
 	f.IntVar(&cfg.MaxRecvMsgSize, "distributor.max-recv-msg-size", 100<<20, "remote_write API max receive message size (bytes).")
+	f.IntVar(&cfg.OTLPMaxRecvMsgSize, "distributor.otlp-max-recv-msg-size", 100<<20, "Maximum OTLP request size in bytes that the Distributor can accept.")
 	f.DurationVar(&cfg.RemoteTimeout, "distributor.remote-timeout", 2*time.Second, "Timeout for downstream ingesters.")
 	f.DurationVar(&cfg.ExtraQueryDelay, "distributor.extra-query-delay", 0, "Time to wait before sending more than the minimum successful query requests.")
 	f.BoolVar(&cfg.ShardByAllLabels, "distributor.shard-by-all-labels", false, "Distribute samples based on all labels, as opposed to solely by user and metric name.")

pkg/util/http.go

@@ -2,6 +2,7 @@ package util
 
 import (
 	"bytes"
+	"compress/gzip"
 	"context"
 	"encoding/json"
 	"flag"
@@ -143,6 +144,7 @@ type CompressionType int
 const (
 	NoCompression CompressionType = iota
 	RawSnappy
+	Gzip
 )
 
 // ParseProtoReader parses a compressed proto from an io.Reader.
@@ -215,6 +217,13 @@ func decompressFromReader(reader io.Reader, expectedSize, maxSize int, compressi
 			return nil, err
 		}
 		body, err = decompressFromBuffer(&buf, maxSize, RawSnappy, sp)
+	case Gzip:
+		reader, err = gzip.NewReader(reader)
+		if err != nil {
+			return nil, err
+		}
+		_, err = buf.ReadFrom(reader)
+		body = buf.Bytes()
 	}
 	return body, err
 }

pkg/util/push/otlp.go

@@ -1,20 +1,24 @@
 package push
 
 import (
+	"bytes"
+	"compress/gzip"
 	"context"
+	"fmt"
+	"io"
 	"net/http"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/prompb"
-	"github.com/prometheus/prometheus/storage/remote"
 	"github.com/prometheus/prometheus/storage/remote/otlptranslator/prometheusremotewrite"
 	"github.com/prometheus/prometheus/util/annotations"
 	"github.com/weaveworks/common/httpgrpc"
 	"github.com/weaveworks/common/middleware"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/pdata/pmetric/pmetricotlp"
 
 	"github.com/cortexproject/cortex/pkg/cortexpb"
 	"github.com/cortexproject/cortex/pkg/distributor"
@@ -24,8 +28,13 @@ import (
 	"github.com/cortexproject/cortex/pkg/util/validation"
 )
 
+const (
+	pbContentType   = "application/x-protobuf"
+	jsonContentType = "application/json"
+)
+
 // OTLPHandler is a http.Handler which accepts OTLP metrics.
-func OTLPHandler(overrides *validation.Overrides, cfg distributor.OTLPConfig, sourceIPs *middleware.SourceIPExtractor, push Func) http.Handler {
+func OTLPHandler(maxRecvMsgSize int, overrides *validation.Overrides, cfg distributor.OTLPConfig, sourceIPs *middleware.SourceIPExtractor, push Func) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		ctx := r.Context()
 		logger := util_log.WithContext(ctx, util_log.Logger)
@@ -42,7 +51,7 @@ func OTLPHandler(overrides *validation.Overrides, cfg distributor.OTLPConfig, so
 			return
 		}
 
-		req, err := remote.DecodeOTLPWriteRequest(r)
+		req, err := decodeOTLPWriteRequest(ctx, r, maxRecvMsgSize)
 		if err != nil {
 			level.Error(logger).Log("err", err.Error())
 			http.Error(w, err.Error(), http.StatusBadRequest)
@@ -90,6 +99,64 @@ func OTLPHandler(overrides *validation.Overrides, cfg distributor.OTLPConfig, so
 	})
 }
 
+func decodeOTLPWriteRequest(ctx context.Context, r *http.Request, maxSize int) (pmetricotlp.ExportRequest, error) {
+	expectedSize := int(r.ContentLength)
+	if expectedSize > maxSize {
+		return pmetricotlp.NewExportRequest(), fmt.Errorf("received message larger than max (%d vs %d)", expectedSize, maxSize)
+	}
+
+	contentType := r.Header.Get("Content-Type")
+	contentEncoding := r.Header.Get("Content-Encoding")
+
+	var compressionType util.CompressionType
+	switch contentEncoding {
+	case "gzip":
+		compressionType = util.Gzip
+	case "":
+		compressionType = util.NoCompression
+	default:
+		return pmetricotlp.NewExportRequest(), fmt.Errorf("unsupported compression: %s, Supported compression types are \"gzip\" or '' (no compression)", contentEncoding)
+	}
+
+	var decoderFunc func(reader io.Reader) (pmetricotlp.ExportRequest, error)
+	switch contentType {
+	case pbContentType:
+		decoderFunc = func(reader io.Reader) (pmetricotlp.ExportRequest, error) {
+			req := pmetricotlp.NewExportRequest()
+			otlpReqProto := otlpProtoMessage{req: &req}
+			return req, util.ParseProtoReader(ctx, reader, expectedSize, maxSize, otlpReqProto, compressionType)
+		}
+	case jsonContentType:
+		decoderFunc = func(reader io.Reader) (pmetricotlp.ExportRequest, error) {
+			req := pmetricotlp.NewExportRequest()
+
+			reader = io.LimitReader(reader, int64(maxSize)+1)
+			if compressionType == util.Gzip {
+				var err error
+				reader, err = gzip.NewReader(reader)
+				if err != nil {
+					return req, err
+				}
+			}
+
+			var buf bytes.Buffer
+			if expectedSize > 0 {
+				buf.Grow(expectedSize + bytes.MinRead) // extra space guarantees no reallocation
+			}
+			_, err := buf.ReadFrom(reader)
+			if err != nil {
+				return req, err
+			}
+
+			return req, req.UnmarshalJSON(buf.Bytes())
+		}
+	default:
+		return pmetricotlp.NewExportRequest(), fmt.Errorf("unsupported content type: %s, supported: [%s, %s]", contentType, jsonContentType, pbContentType)
+	}
+
+	return decoderFunc(r.Body)
+}
+
 func convertToPromTS(ctx context.Context, pmetrics pmetric.Metrics, cfg distributor.OTLPConfig, overrides *validation.Overrides, userID string, logger log.Logger) ([]prompb.TimeSeries, error) {
 	promConverter := prometheusremotewrite.NewPrometheusConverter()
 	settings := prometheusremotewrite.Settings{
@@ -223,3 +290,16 @@ func joinAttributeMaps(from, to pcommon.Map) {
 		return true
 	})
 }
+
+// otlpProtoMessage Implements proto.Meesage, proto.Unmarshaler
+type otlpProtoMessage struct {
+	req *pmetricotlp.ExportRequest
+}
+
+func (otlpProtoMessage) ProtoMessage() {}
+
+func (otlpProtoMessage) Reset() {}
+
+func (otlpProtoMessage) String() string { return "" }
+
+func (o otlpProtoMessage) Unmarshal(data []byte) error { return o.req.UnmarshalProto(data) }