Allow to disable http2 for GCS. (#4942)

* Allow to disable http2 for GCS.

This also tweaks our iddle connection pooling accross the board and reduce the insane parallelism when fetching chunks.

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* update changelog

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* Update pkg/storage/chunk/gcp/gcs_object_client.go

Co-authored-by: Danny Kopping <dannykopping@gmail.com>

* update comment

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* Update docs/sources/configuration/_index.md

Co-authored-by: Karen Miller <84039272+KMiller-Grafana@users.noreply.github.com>

* Update CHANGELOG.md

Co-authored-by: Karen Miller <84039272+KMiller-Grafana@users.noreply.github.com>

* Reduce MaxIdleConns to a more standard value.

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* Allow to configure max parallelism for fetching  chunks

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

* Fixes tests with no default config

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

Co-authored-by: Danny Kopping <dannykopping@gmail.com>
Co-authored-by: Karen Miller <84039272+KMiller-Grafana@users.noreply.github.com>

CHANGELOG.md

@@ -24,6 +24,7 @@
 * [4892](https://github.com/grafana/loki/pull/4892) **cristaloleg**: Loki: upgrade cristalhq/hedgedhttp from v0.6.0 to v0.7.0
 * [4902](https://github.com/grafana/loki/pull/4902) **cyriltovena**: Fixes 500 when query is outside of max_query_lookback.
 * [4904](https://github.com/grafana/loki/pull/4904) **bboreham**: Fixes rare race condition that could crash an ingester.
+* [4942](https://github.com/grafana/loki/pull/4942) **cyriltovena**: Allow to disable HTTP/2 for GCS.
 * [4876](https://github.com/grafana/loki/pull/4876) **trevorwhitney**: Docs: add simple, scalable example using docker-compose
 
 # 2.4.1 (2021/11/07)

docs/sources/configuration/_index.md

@@ -716,6 +716,10 @@ The `gcs_storage_config` configures GCS as a general storage for different data
 # The duration after which the requests to GCS should be timed out.
 # CLI flag: -<prefix>.gcs.request-timeout
 [request_timeout: <duration> | default = 0s]
+
+# Enable HTTP/2 when connecting to GCS.
+# CLI flag: -<prefix>.gcs.enable-http2
+[enable_http2: <bool> | default = true]
 ```
 
 ## s3_storage_config

pkg/storage/chunk/aws/s3_storage_client.go

@@ -299,9 +299,9 @@ func buildS3Client(cfg S3Config, hedgingCfg hedging.Config, hedging bool) (*s3.S
 			KeepAlive: 30 * time.Second,
 			DualStack: true,
 		}).DialContext,
-		MaxIdleConns:          100,
+		MaxIdleConns:          200,
 		IdleConnTimeout:       cfg.HTTPConfig.IdleConnTimeout,
-		MaxIdleConnsPerHost:   100,
+		MaxIdleConnsPerHost:   200,
 		TLSHandshakeTimeout:   3 * time.Second,
 		ExpectContinueTimeout: 1 * time.Second,
 		ResponseHeaderTimeout: cfg.HTTPConfig.ResponseHeaderTimeout,

pkg/storage/chunk/azure/blob_storage_client.go

@@ -82,8 +82,8 @@ var (
 					KeepAlive: 30 * time.Second,
 					DualStack: true,
 				}).Dial,
-				MaxIdleConns:           0,
-				MaxIdleConnsPerHost:    100,
+				MaxIdleConns:           200,
+				MaxIdleConnsPerHost:    200,
 				IdleConnTimeout:        90 * time.Second,
 				TLSHandshakeTimeout:    10 * time.Second,
 				ExpectContinueTimeout:  1 * time.Second,
@@ -314,7 +314,6 @@ func (b *BlobStorage) newPipeline(hedgingCfg hedging.Config, hedging bool) (pipe
 	}
 
 	return azblob.NewPipeline(*tokenCredential, opts), nil
-
 }
 
 func (b *BlobStorage) getOAuthToken() (*azblob.TokenCredential, error) {
@@ -353,7 +352,6 @@ func (b *BlobStorage) fetchMSIToken() (*adal.ServicePrincipalToken, error) {
 
 	// both can be empty, systemAssignedMSI scenario
 	spt, err := adal.NewServicePrincipalTokenFromMSI(msiEndpoint, "https://storage.azure.com/")
-
 	if err != nil {
 		return nil, err
 	}

pkg/storage/chunk/cassandra/fixtures.go

@@ -41,7 +41,7 @@ func (f *fixture) Clients() (chunk.IndexClient, chunk.Client, chunk.TableClient,
 		return nil, nil, nil, schemaConfig, nil, err
 	}
 
-	objectClient, err := NewObjectClient(cfg, schemaConfig, nil)
+	objectClient, err := NewObjectClient(cfg, schemaConfig, nil, 150)
 	if err != nil {
 		return nil, nil, nil, schemaConfig, nil, err
 	}

pkg/storage/chunk/cassandra/storage_client.go

@@ -446,10 +446,11 @@ type ObjectClient struct {
 	readSession    *gocql.Session
 	writeSession   *gocql.Session
 	querySemaphore *semaphore.Weighted
+	maxGetParallel int
 }
 
 // NewObjectClient returns a new ObjectClient.
-func NewObjectClient(cfg Config, schemaCfg chunk.SchemaConfig, registerer prometheus.Registerer) (*ObjectClient, error) {
+func NewObjectClient(cfg Config, schemaCfg chunk.SchemaConfig, registerer prometheus.Registerer, maxGetParallel int) (*ObjectClient, error) {
 	readSession, err := cfg.session("chunks-read", registerer)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -471,6 +472,7 @@ func NewObjectClient(cfg Config, schemaCfg chunk.SchemaConfig, registerer promet
 		readSession:    readSession,
 		writeSession:   writeSession,
 		querySemaphore: querySemaphore,
+		maxGetParallel: maxGetParallel,
 	}
 	return client, nil
 }
@@ -501,7 +503,7 @@ func (s *ObjectClient) PutChunks(ctx context.Context, chunks []chunk.Chunk) erro
 
 // GetChunks implements chunk.ObjectClient.
 func (s *ObjectClient) GetChunks(ctx context.Context, input []chunk.Chunk) ([]chunk.Chunk, error) {
-	return util.GetParallelChunks(ctx, input, s.getChunk)
+	return util.GetParallelChunks(ctx, s.maxGetParallel, input, s.getChunk)
 }
 
 func (s *ObjectClient) getChunk(ctx context.Context, decodeContext *chunk.DecodeContext, input chunk.Chunk) (chunk.Chunk, error) {

pkg/storage/chunk/gcp/gcs_object_client.go

@@ -33,6 +33,7 @@ type GCSConfig struct {
 	ChunkBufferSize  int           `yaml:"chunk_buffer_size"`
 	RequestTimeout   time.Duration `yaml:"request_timeout"`
 	EnableOpenCensus bool          `yaml:"enable_opencensus"`
+	EnableHTTP2      bool          `yaml:"enable_http2"`
 
 	Insecure bool `yaml:"-"`
 }
@@ -47,7 +48,8 @@ func (cfg *GCSConfig) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet) {
 	f.StringVar(&cfg.BucketName, prefix+"gcs.bucketname", "", "Name of GCS bucket. Please refer to https://cloud.google.com/docs/authentication/production for more information about how to configure authentication.")
 	f.IntVar(&cfg.ChunkBufferSize, prefix+"gcs.chunk-buffer-size", 0, "The size of the buffer that GCS client for each PUT request. 0 to disable buffering.")
 	f.DurationVar(&cfg.RequestTimeout, prefix+"gcs.request-timeout", 0, "The duration after which the requests to GCS should be timed out.")
-	f.BoolVar(&cfg.EnableOpenCensus, prefix+"gcs.enable-opencensus", true, "Enabled OpenCensus (OC) instrumentation for all requests.")
+	f.BoolVar(&cfg.EnableOpenCensus, prefix+"gcs.enable-opencensus", true, "Enable OpenCensus (OC) instrumentation for all requests.")
+	f.BoolVar(&cfg.EnableHTTP2, prefix+"gcs.enable-http2", true, "Enable HTTP2 connections.")
 }
 
 func (cfg *GCSConfig) ToCortexGCSConfig() cortex_gcp.GCSConfig {
@@ -82,7 +84,7 @@ func newGCSObjectClient(ctx context.Context, cfg GCSConfig, hedgingCfg hedging.C
 
 func newBucketHandle(ctx context.Context, cfg GCSConfig, hedgingCfg hedging.Config, hedging bool, clientFactory ClientFactory) (*storage.BucketHandle, error) {
 	var opts []option.ClientOption
-	httpClient, err := gcsInstrumentation(ctx, storage.ScopeReadWrite, cfg.Insecure)
+	httpClient, err := gcsInstrumentation(ctx, storage.ScopeReadWrite, cfg.Insecure, cfg.EnableHTTP2)
 	if err != nil {
 		return nil, err
 	}

pkg/storage/chunk/gcp/instrumentation.go

@@ -50,9 +50,16 @@ func bigtableInstrumentation() ([]grpc.UnaryClientInterceptor, []grpc.StreamClie
 		}
 }
 
-func gcsInstrumentation(ctx context.Context, scope string, insecure bool) (*http.Client, error) {
+func gcsInstrumentation(ctx context.Context, scope string, insecure bool, http2 bool) (*http.Client, error) {
 	// start with default transport
 	customTransport := http.DefaultTransport.(*http.Transport).Clone()
+	customTransport.MaxIdleConnsPerHost = 200
+	customTransport.MaxIdleConns = 200
+	if !http2 {
+		// disable HTTP/2 by setting TLSNextProto to non-nil empty map, as per the net/http documentation.
+		// see http2 section of https://pkg.go.dev/net/http
+		customTransport.TLSNextProto = make(map[string]func(string, *tls.Conn) http.RoundTripper)
+	}
 	if insecure {
 		customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
 	}

pkg/storage/chunk/objectclient/client.go

@@ -22,17 +22,25 @@ var Base64Encoder = func(key string) string {
 	return base64.StdEncoding.EncodeToString([]byte(key))
 }
 
+const defaultMaxParallel = 150
+
 // Client is used to store chunks in object store backends
 type Client struct {
-	store      chunk.ObjectClient
-	keyEncoder KeyEncoder
+	store               chunk.ObjectClient
+	keyEncoder          KeyEncoder
+	getChunkMaxParallel int
 }
 
 // NewClient wraps the provided ObjectClient with a chunk.Client implementation
 func NewClient(store chunk.ObjectClient, encoder KeyEncoder) *Client {
+	return NewClientWithMaxParallel(store, encoder, defaultMaxParallel)
+}
+
+func NewClientWithMaxParallel(store chunk.ObjectClient, encoder KeyEncoder, maxParallel int) *Client {
 	return &Client{
-		store:      store,
-		keyEncoder: encoder,
+		store:               store,
+		keyEncoder:          encoder,
+		getChunkMaxParallel: maxParallel,
 	}
 }
 
@@ -82,7 +90,11 @@ func (o *Client) PutChunks(ctx context.Context, chunks []chunk.Chunk) error {
 
 // GetChunks retrieves the specified chunks from the configured backend
 func (o *Client) GetChunks(ctx context.Context, chunks []chunk.Chunk) ([]chunk.Chunk, error) {
-	return util.GetParallelChunks(ctx, chunks, o.getChunk)
+	getChunkMaxParallel := o.getChunkMaxParallel
+	if getChunkMaxParallel == 0 {
+		getChunkMaxParallel = defaultMaxParallel
+	}
+	return util.GetParallelChunks(ctx, getChunkMaxParallel, chunks, o.getChunk)
 }
 
 func (o *Client) getChunk(ctx context.Context, decodeContext *chunk.DecodeContext, c chunk.Chunk) (chunk.Chunk, error) {

pkg/storage/chunk/openstack/swift_object_client.go

@@ -24,7 +24,8 @@ import (
 
 var defaultTransport http.RoundTripper = &http.Transport{
 	Proxy:                 http.ProxyFromEnvironment,
-	MaxIdleConnsPerHost:   512,
+	MaxIdleConnsPerHost:   200,
+	MaxIdleConns:          200,
 	ExpectContinueTimeout: 5 * time.Second,
 }
 

pkg/storage/chunk/storage/factory.go

@@ -94,6 +94,7 @@ type Config struct {
 
 	IndexQueriesCacheConfig  cache.Config `yaml:"index_queries_cache_config"`
 	DisableBroadIndexQueries bool         `yaml:"disable_broad_index_queries"`
+	MaxParallelGetChunk      int          `yaml:"max_parallel_get_chunk"`
 
 	GrpcConfig grpc.Config `yaml:"grpc_store"`
 
@@ -117,6 +118,7 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	cfg.IndexQueriesCacheConfig.RegisterFlagsWithPrefix("store.index-cache-read.", "Cache config for index entry reading.", f)
 	f.DurationVar(&cfg.IndexCacheValidity, "store.index-cache-validity", 5*time.Minute, "Cache validity for active index entries. Should be no higher than -ingester.max-chunk-idle.")
 	f.BoolVar(&cfg.DisableBroadIndexQueries, "store.disable-broad-index-queries", false, "Disable broad index queries which results in reduced cache usage and faster query performance at the expense of somewhat higher QPS on the index store.")
+	f.IntVar(&cfg.MaxParallelGetChunk, "store.max-parallel-get-chunk", 150, "Maximum number of parallel chunk reads.")
 }
 
 // Validate config and returns error on failure
@@ -271,7 +273,11 @@ func NewChunkClient(name string, cfg Config, schemaCfg chunk.SchemaConfig, regis
 	case StorageTypeInMemory:
 		return chunk.NewMockStorage(), nil
 	case StorageTypeAWS, StorageTypeS3:
-		return newChunkClientFromStore(aws.NewS3ObjectClient(cfg.AWSStorageConfig.S3Config, cfg.Hedging))
+		c, err := aws.NewS3ObjectClient(cfg.AWSStorageConfig.S3Config, cfg.Hedging)
+		if err != nil {
+			return nil, err
+		}
+		return objectclient.NewClientWithMaxParallel(c, nil, cfg.MaxParallelGetChunk), nil
 	case StorageTypeAWSDynamo:
 		if cfg.AWSStorageConfig.DynamoDB.URL == nil {
 			return nil, fmt.Errorf("Must set -dynamodb.url in aws mode")
@@ -282,23 +288,35 @@ func NewChunkClient(name string, cfg Config, schemaCfg chunk.SchemaConfig, regis
 		}
 		return aws.NewDynamoDBChunkClient(cfg.AWSStorageConfig.DynamoDBConfig, schemaCfg, registerer)
 	case StorageTypeAzure:
-		return newChunkClientFromStore(azure.NewBlobStorage(&cfg.AzureStorageConfig, cfg.Hedging))
+		c, err := azure.NewBlobStorage(&cfg.AzureStorageConfig, cfg.Hedging)
+		if err != nil {
+			return nil, err
+		}
+		return objectclient.NewClientWithMaxParallel(c, nil, cfg.MaxParallelGetChunk), nil
 	case StorageTypeGCP:
 		return gcp.NewBigtableObjectClient(context.Background(), cfg.GCPStorageConfig, schemaCfg)
 	case StorageTypeGCPColumnKey, StorageTypeBigTable, StorageTypeBigTableHashed:
 		return gcp.NewBigtableObjectClient(context.Background(), cfg.GCPStorageConfig, schemaCfg)
 	case StorageTypeGCS:
-		return newChunkClientFromStore(gcp.NewGCSObjectClient(context.Background(), cfg.GCSConfig, cfg.Hedging))
+		c, err := gcp.NewGCSObjectClient(context.Background(), cfg.GCSConfig, cfg.Hedging)
+		if err != nil {
+			return nil, err
+		}
+		return objectclient.NewClientWithMaxParallel(c, nil, cfg.MaxParallelGetChunk), nil
 	case StorageTypeSwift:
-		return newChunkClientFromStore(openstack.NewSwiftObjectClient(cfg.Swift, cfg.Hedging))
+		c, err := openstack.NewSwiftObjectClient(cfg.Swift, cfg.Hedging)
+		if err != nil {
+			return nil, err
+		}
+		return objectclient.NewClientWithMaxParallel(c, nil, cfg.MaxParallelGetChunk), nil
 	case StorageTypeCassandra:
-		return cassandra.NewObjectClient(cfg.CassandraStorageConfig, schemaCfg, registerer)
+		return cassandra.NewObjectClient(cfg.CassandraStorageConfig, schemaCfg, registerer, cfg.MaxParallelGetChunk)
 	case StorageTypeFileSystem:
 		store, err := local.NewFSObjectClient(cfg.FSConfig)
 		if err != nil {
 			return nil, err
 		}
-		return objectclient.NewClient(store, objectclient.Base64Encoder), nil
+		return objectclient.NewClientWithMaxParallel(store, objectclient.Base64Encoder, cfg.MaxParallelGetChunk), nil
 	case StorageTypeGrpc:
 		return grpc.NewStorageClient(cfg.GrpcConfig, schemaCfg)
 	default:
@@ -306,13 +324,6 @@ func NewChunkClient(name string, cfg Config, schemaCfg chunk.SchemaConfig, regis
 	}
 }
 
-func newChunkClientFromStore(store chunk.ObjectClient, err error) (chunk.Client, error) {
-	if err != nil {
-		return nil, err
-	}
-	return objectclient.NewClient(store, nil), nil
-}
-
 // NewTableClient makes a new table client based on the configuration.
 func NewTableClient(name string, cfg Config, registerer prometheus.Registerer) (chunk.TableClient, error) {
 	if indexClientFactory, ok := customIndexStores[name]; ok {

pkg/storage/chunk/util/parallel_chunk_fetch.go

@@ -11,8 +11,6 @@ import (
 	"github.com/grafana/loki/pkg/storage/chunk"
 )
 
-const maxParallel = 1000
-
 var decodeContextPool = sync.Pool{
 	New: func() interface{} {
 		return chunk.NewDecodeContext()
@@ -20,7 +18,7 @@ var decodeContextPool = sync.Pool{
 }
 
 // GetParallelChunks fetches chunks in parallel (up to maxParallel).
-func GetParallelChunks(ctx context.Context, chunks []chunk.Chunk, f func(context.Context, *chunk.DecodeContext, chunk.Chunk) (chunk.Chunk, error)) ([]chunk.Chunk, error) {
+func GetParallelChunks(ctx context.Context, maxParallel int, chunks []chunk.Chunk, f func(context.Context, *chunk.DecodeContext, chunk.Chunk) (chunk.Chunk, error)) ([]chunk.Chunk, error) {
 	log, ctx := spanlogger.New(ctx, "GetParallelChunks")
 	defer log.Finish()
 	log.LogFields(otlog.Int("requested", len(chunks)))

pkg/storage/chunk/util/parallel_chunk_fetch_test.go

@@ -12,7 +12,7 @@ func BenchmarkGetParallelChunks(b *testing.B) {
 	in := make([]chunk.Chunk, 1024)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		res, err := GetParallelChunks(ctx, in,
+		res, err := GetParallelChunks(ctx, 150, in,
 			func(_ context.Context, d *chunk.DecodeContext, c chunk.Chunk) (chunk.Chunk, error) {
 				return c, nil
 			})

pkg/storage/stores/shipper/compactor/retention/util_test.go

@@ -229,6 +229,7 @@ func newTestStore(t testing.TB) *testStore {
 			FSConfig: local.FSConfig{
 				Directory: chunkDir,
 			},
+			MaxParallelGetChunk: 150,
 		},
 		BoltDBShipperConfig: shipper.Config{
 			ActiveIndexDirectory: indexDir,