Default force_attempt_http2 to true and allow configuration (#5050)

* Default force_attempt_http2 to true and allow configuration

* update changelog

* Fix tests and default faro behavior

Author: dehaansa

CHANGELOG.md

@@ -61,6 +61,8 @@ Main (unreleased)
 
 - Fix Docker log corruption for multiplexed long lines. (@axd1x8a)
 
+- Allow configuration of `force_attempt_http2` and default it to `true` for otelcol exporters with HTTP client configurations. (@dehaansa)
+
 v1.12.0
 -----------------
 

docs/sources/reference/components/otelcol/otelcol.exporter.splunkhec.md

@@ -149,6 +149,7 @@ The following arguments are supported:
 | Name                      | Type       | Description                                                                                     | Default | Required |
 |---------------------------|------------|-------------------------------------------------------------------------------------------------|---------|----------|
 | `endpoint`                | `string`   | The Splunk HEC endpoint to use.                                                                 |         | yes      |
+| `force_attempt_http2`     | `bool`     | Force the HTTP client to try to use the HTTP/2 protocol.                                        | `true`  | no       |
 | `disable_keep_alives`     | `bool`     | Disable HTTP keep-alive.                                                                        | `false` | no       |
 | `idle_conn_timeout`       | `duration` | Time to wait before an idle connection closes itself.                                           | `"45s"` | no       |
 | `insecure_skip_verify`    | `bool`     | Ignores insecure server TLS certificates.                                                       | `false` | no       |

docs/sources/shared/reference/components/otelcol-http-client-block.md

@@ -12,6 +12,7 @@ The following arguments are supported:
 | `auth`                    | `capsule(otelcol.Handler)` | Handler from an `otelcol.auth` component to use for authenticating requests.                                       |            | no       |
 | `compression`             | `string`                   | Compression mechanism to use for requests.                                                                         | `"gzip"`   | no       |
 | `disable_keep_alives`     | `bool`                     | Disable HTTP keep-alive.                                                                                           | `false`    | no       |
+| `force_attempt_http2`     | `bool`                     | Force the HTTP client to try to use the HTTP/2 protocol.                                                           | `true`     | no       |
 | `headers`                 | `map(string)`              | Additional headers to send with the request.                                                                       | `{}`       | no       |
 | `http2_ping_timeout`      | `duration`                 | Timeout after which the connection will be closed if a response to Ping isn't received.                            | `"15s"`    | no       |
 | `http2_read_idle_timeout` | `duration`                 | Timeout after which a health check using ping frame will be carried out if no frame is received on the connection. | `"0s"`     | no       |
@@ -36,4 +37,7 @@ If `http2_ping_timeout` is unset or set to `0s`, it will default to `15s`.
 
 If `http2_read_idle_timeout` is unset or set to `0s`, then no health check will be performed.
 
+Golang's default HTTP transport attempts HTTP/2 by default, however some settings (`max_conns_per_host`, `max_idle_conns_per_host`, `max_idle_conns`) are only relevant for HTTP/1.
+The `force_attempt_http2` attribute allows a user to only attempt HTTP/1.
+
 {{< docs/shared lookup="reference/components/otelcol-compression-field.md" source="alloy" version="<ALLOY_VERSION>" >}}

internal/component/otelcol/config_http.go

@@ -148,6 +148,7 @@ type HTTPClientArguments struct {
 	DisableKeepAlives    bool              `alloy:"disable_keep_alives,attr,optional"`
 	HTTP2ReadIdleTimeout time.Duration     `alloy:"http2_read_idle_timeout,attr,optional"`
 	HTTP2PingTimeout     time.Duration     `alloy:"http2_ping_timeout,attr,optional"`
+	ForceAttemptHTTP2    bool              `alloy:"force_attempt_http2,attr,optional"`
 
 	// Auth is a binding to an otelcol.auth.* component extension which handles
 	// authentication.
@@ -198,6 +199,7 @@ func (args *HTTPClientArguments) Convert() (*otelconfighttp.ClientConfig, error)
 		DisableKeepAlives:    args.DisableKeepAlives,
 		HTTP2ReadIdleTimeout: args.HTTP2ReadIdleTimeout,
 		HTTP2PingTimeout:     args.HTTP2PingTimeout,
+		ForceAttemptHTTP2:    args.ForceAttemptHTTP2,
 
 		Auth: authentication,
 

internal/component/otelcol/exporter/faro/faro.go

@@ -99,11 +99,12 @@ type HTTPClientArguments otelcol.HTTPClientArguments
 // SetToDefault implements syntax.Defaulter.
 func (args *HTTPClientArguments) SetToDefault() {
 	*args = HTTPClientArguments{
-		Timeout:         30 * time.Second,
-		MaxIdleConns:    100,
-		IdleConnTimeout: 90 * time.Second,
-		Headers:         map[string]string{},
-		Compression:     otelcol.CompressionTypeGzip,
-		WriteBufferSize: 512 * 1024,
+		Timeout:           30 * time.Second,
+		MaxIdleConns:      100,
+		IdleConnTimeout:   90 * time.Second,
+		Headers:           map[string]string{},
+		Compression:       otelcol.CompressionTypeGzip,
+		WriteBufferSize:   512 * 1024,
+		ForceAttemptHTTP2: true,
 	}
 }

internal/component/otelcol/exporter/faro/faro_test.go

@@ -37,6 +37,7 @@ func TestConfigConversion(t *testing.T) {
 					headers = {
 						"X-Scope-OrgID" = "123",
 					}
+					force_attempt_http2 = false
 				}
 				sending_queue {
 					enabled = true
@@ -63,6 +64,7 @@ func TestConfigConversion(t *testing.T) {
 					Headers: configopaque.MapList{
 						configopaque.Pair{Name: "X-Scope-OrgID", Value: "123"},
 					},
+					ForceAttemptHTTP2: false,
 				},
 				QueueConfig: defaultQueueConfig,
 				RetryConfig: configretry.BackOffConfig{
@@ -84,13 +86,14 @@ func TestConfigConversion(t *testing.T) {
 			`,
 			expected: faroexporter.Config{
 				ClientConfig: confighttp.ClientConfig{
-					Endpoint:        "https://faro.example.com/collect",
-					Timeout:         defaultTimeout,
-					Compression:     "gzip",
-					WriteBufferSize: 512 * 1024,
-					MaxIdleConns:    100,
-					IdleConnTimeout: 90 * time.Second,
-					Headers:         configopaque.MapList{},
+					Endpoint:          "https://faro.example.com/collect",
+					Timeout:           defaultTimeout,
+					Compression:       "gzip",
+					WriteBufferSize:   512 * 1024,
+					MaxIdleConns:      100,
+					IdleConnTimeout:   90 * time.Second,
+					Headers:           configopaque.MapList{},
+					ForceAttemptHTTP2: true,
 				},
 				QueueConfig: defaultQueueConfig,
 				RetryConfig: defaultRetrySettings,

internal/component/otelcol/exporter/otlphttp/otlphttp.go

@@ -137,11 +137,12 @@ func (args *HTTPClientArguments) SetToDefault() {
 		MaxIdleConns:    maxIdleConns,
 		IdleConnTimeout: idleConnTimeout,
 
-		Timeout:          30 * time.Second,
-		Headers:          map[string]string{},
-		Compression:      otelcol.CompressionTypeGzip,
-		ReadBufferSize:   0,
-		WriteBufferSize:  512 * 1024,
-		HTTP2PingTimeout: 15 * time.Second,
+		Timeout:           30 * time.Second,
+		Headers:           map[string]string{},
+		Compression:       otelcol.CompressionTypeGzip,
+		ReadBufferSize:    0,
+		WriteBufferSize:   512 * 1024,
+		HTTP2PingTimeout:  15 * time.Second,
+		ForceAttemptHTTP2: true,
 	}
 }

internal/component/otelcol/exporter/splunkhec/config/splunkhec.go

@@ -60,6 +60,8 @@ type SplunkHecClientArguments struct {
 	DisableKeepAlives bool `alloy:"disable_keep_alives,attr,optional"`
 	// TLSSetting for the HTTP client.
 	InsecureSkipVerify bool `alloy:"insecure_skip_verify,attr,optional"`
+	// ForceAttemptHTTP2 for the HTTP client.
+	ForceAttemptHTTP2 bool `alloy:"force_attempt_http2,attr,optional"`
 }
 type SplunkConf struct {
 	// DeprecatedBatcher is the deprecated batcher configuration.
@@ -230,6 +232,7 @@ func (args *SplunkHecClientArguments) Convert() *confighttp.ClientConfig {
 		MaxConnsPerHost:     args.MaxConnsPerHost,
 		IdleConnTimeout:     args.IdleConnTimeout,
 		DisableKeepAlives:   args.DisableKeepAlives,
+		ForceAttemptHTTP2:   args.ForceAttemptHTTP2,
 		TLS: configtls.ClientConfig{
 			InsecureSkipVerify: args.InsecureSkipVerify,
 		},
@@ -240,6 +243,7 @@ func (args *SplunkHecClientArguments) SetToDefault() {
 	args.Timeout = 15 * time.Second
 	args.MaxIdleConns = 100
 	args.IdleConnTimeout = 90 * time.Second
+	args.ForceAttemptHTTP2 = true
 }
 
 func (args *SplunkHecClientArguments) Validate() error {

internal/component/otelcol/exporter/splunkhec/splunkhec_test.go

@@ -52,6 +52,7 @@ func TestConfigConversion(t *testing.T) {
 			HTTP2ReadIdleTimeout: 0,
 			HTTP2PingTimeout:     0,
 			Cookies:              confighttp.CookiesConfig{},
+			ForceAttemptHTTP2:    true,
 		},
 		QueueSettings: exporterhelper.QueueBatchConfig{
 			Enabled:      true,
@@ -139,6 +140,7 @@ func TestConfigConversion(t *testing.T) {
 			DisableKeepAlives:    false,
 			HTTP2ReadIdleTimeout: 0,
 			HTTP2PingTimeout:     0,
+			ForceAttemptHTTP2:    true,
 			Cookies:              confighttp.CookiesConfig{}},
 		QueueSettings: exporterhelper.QueueBatchConfig{
 			Enabled:      true,

internal/converter/internal/otelcolconvert/converter_faroexporter.go

@@ -91,6 +91,7 @@ func toFaroHTTPClientArguments(cfg confighttp.ClientConfig) faro.HTTPClientArgum
 		DisableKeepAlives:    cfg.DisableKeepAlives,
 		HTTP2PingTimeout:     cfg.HTTP2PingTimeout,
 		HTTP2ReadIdleTimeout: cfg.HTTP2ReadIdleTimeout,
+		ForceAttemptHTTP2:    cfg.ForceAttemptHTTP2,
 
 		Authentication: a,
 	}