report, main, client: Tweak concurrency, reporting

client.go

@@ -9,10 +9,12 @@ import (
 )
 
 type clientStats struct {
-	mu        sync.Mutex
-	NumTotal  int           // Number of requests
-	NumErrors int           // Number of errors
-	TimeTotal time.Duration // Total duration of requests
+	mu         sync.Mutex
+	NumTotal   int           // Number of requests
+	NumErrors  int           // Number of errors
+	TimeErrors time.Duration // Duration of error responses specifically
+	TimeTotal  time.Duration // Total duration of requests
+	Errors     map[string]int
 }
 
 func (stats *clientStats) Count(err error, elapsed time.Duration) {
@@ -22,17 +24,21 @@ func (stats *clientStats) Count(err error, elapsed time.Duration) {
 	stats.NumTotal += 1
 	if err != nil {
 		stats.NumErrors += 1
+		stats.TimeErrors += elapsed
+
+		if stats.Errors == nil {
+			stats.Errors = map[string]int{}
+		}
+		stats.Errors[err.Error()] += 1
 	}
 	stats.TimeTotal += elapsed
 }
 
-const chanBuffer = 20
-
 func NewClient(endpoint string, concurrency int) (*Client, error) {
 	c := Client{
 		Endpoint:    endpoint,
 		Concurrency: concurrency,
-		In:          make(chan Request, chanBuffer),
+		In:          make(chan Request, 2*concurrency),
 	}
 	return &c, nil
 }

main.go

@@ -123,10 +123,15 @@ func run(ctx context.Context, options Options) error {
 		timeout = d
 	}
 
+	if options.Concurrency < 1 {
+		logger.Info().Int("concurrency", options.Concurrency).Msg("concurrency is less than 1, overriding to 1")
+		options.Concurrency = 1
+	}
+
 	g, ctx := errgroup.WithContext(ctx)
 
 	// responses is closed when clients are shut down
-	responses := make(chan Response, chanBuffer)
+	responses := make(chan Response, options.Concurrency*2)
 
 	// Launch clients
 	clients, err := NewClients(options.Args.Endpoints, options.Concurrency, timeout)

report.go

@@ -27,10 +27,13 @@ type report struct {
 }
 
 func (r *report) Render(w io.Writer) error {
+	elapsedAvg := r.elapsed / time.Duration(r.requests)
+	errorRate := float64(r.errors*100) / float64(r.requests)
+
 	fmt.Fprintf(w, "\n* Report for %d endpoints:\n", len(r.Clients))
 	fmt.Fprintf(w, "  Completed:  %d results with %d total requests\n", r.completed, r.requests)
-	fmt.Fprintf(w, "  Elapsed:    %s spent on requests, %s total run time\n", r.elapsed, time.Now().Sub(r.started))
-	fmt.Fprintf(w, "  Errors:     %d\n", r.errors)
+	fmt.Fprintf(w, "  Elapsed:    %s request avg, %s total run time\n", elapsedAvg, time.Now().Sub(r.started))
+	fmt.Fprintf(w, "  Errors:     %d (%0.2f%%)\n", r.errors, errorRate)
 	fmt.Fprintf(w, "  Mismatched: %d\n", r.mismatched)
 
 	if r.overloaded > 0 {