add inflight option to vespa feed

client/go/internal/cli/cmd/feed.go

@@ -18,6 +18,7 @@ import (
 
 func addFeedFlags(cli *CLI, cmd *cobra.Command, options *feedOptions) {
 	cmd.PersistentFlags().IntVar(&options.connections, "connections", 8, "The number of connections to use")
+	cmd.PersistentFlags().IntVar(&options.inflight, "inflight", 0, "The target number of inflight requests. 0 to dynamically detect the best value (default 0)")
 	cmd.PersistentFlags().StringVar(&options.compression, "compression", "auto", `Whether to compress the document data when sending the HTTP request. Default is "auto", which compresses large documents. Must be "auto", "gzip" or "none"`)
 	cmd.PersistentFlags().IntVar(&options.timeoutSecs, "timeout", 0, "Individual feed operation timeout in seconds. 0 to disable (default 0)")
 	cmd.Flags().StringSliceVarP(&options.headers, "header", "", nil, "Add a header to all HTTP requests, on the format 'Header: Value'. This can be specified multiple times")
@@ -40,6 +41,7 @@ func addFeedFlags(cli *CLI, cmd *cobra.Command, options *feedOptions) {
 
 type feedOptions struct {
 	connections    int
+	inflight       int
 	compression    string
 	route          string
 	verbose        bool
@@ -257,7 +259,7 @@ func feed(files []string, options feedOptions, cli *CLI, cmd *cobra.Command) err
 	if err != nil {
 		return err
 	}
-	throttler := document.NewThrottler(options.connections)
+	throttler := document.NewThrottler(options.connections, options.inflight)
 	circuitBreaker := document.NewCircuitBreaker(10*time.Second, time.Duration(options.doomSecs)*time.Second)
 	dispatcher := document.NewDispatcher(client, throttler, circuitBreaker, cli.Stderr, options.verbose)
 	start := cli.now()

client/go/internal/vespa/document/throttler.go

@@ -21,6 +21,15 @@ type Throttler interface {
 	TargetInflight() int64
 }
 
+type staticThrottler struct {
+	inflight int
+}
+
+func (*staticThrottler) Sent()                   {}
+func (*staticThrottler) Success()                {}
+func (*staticThrottler) Throttled(count int64)   {}
+func (s *staticThrottler) TargetInflight() int64 { return int64(s.inflight) }
+
 type dynamicThrottler struct {
 	minInflight    int64
 	maxInflight    int64
@@ -54,7 +63,12 @@ func newThrottler(connections int, nowFunc func() time.Time) *dynamicThrottler {
 	return t
 }
 
-func NewThrottler(connections int) Throttler { return newThrottler(connections, time.Now) }
+func NewThrottler(connections int, inflight int) Throttler {
+	if inflight > 0 {
+		return &staticThrottler{inflight}
+	}
+	return newThrottler(connections, time.Now)
+}
 
 func (t *dynamicThrottler) Sent() {
 	currentInflight := t.TargetInflight()