Added LogAllErrors config parameter to Server, which allows logging the most frequent errors such as 'connection reset by peer', 'broken pipe' and 'i/o timeout'. By default such errors are suppressed

server.go

@@ -201,6 +201,16 @@ type Server struct {
 	// Server accepts all the requests by default.
 	GetOnly bool
 
+	// Logs all errors, including the most frequent
+	// 'connection reset by peer', 'broken pipe' and 'connection timeout'
+	// errors. Such errors are common in production serving real-world
+	// clients.
+	//
+	// By default the most frequent errors such as
+	// 'connection reset by peer', 'broken pipe' and 'connection timeout'
+	// are suppressed in order to limit output log traffic.
+	LogAllErrors bool
+
 	// Logger, which is used by RequestCtx.Logger().
 	//
 	// By default standard logger from log package is used.
@@ -1062,6 +1072,7 @@ func (s *Server) Serve(ln net.Listener) error {
 	wp := &workerPool{
 		WorkerFunc:      s.serveConn,
 		MaxWorkersCount: maxWorkersCount,
+		LogAllErrors:    s.LogAllErrors,
 		Logger:          s.logger(),
 	}
 	wp.Start()

workerpool.go

@@ -19,10 +19,10 @@ type workerPool struct {
 	// It must leave c unclosed.
 	WorkerFunc func(c net.Conn) error
 
-	// Maximum number of workers to create.
 	MaxWorkersCount int
 
-	// Logger used by workerPool.
+	LogAllErrors bool
+
 	Logger Logger
 
 	lock         sync.Mutex
@@ -194,8 +194,9 @@ func (wp *workerPool) workerFunc(ch *workerChan) {
 		}
 		if err = wp.WorkerFunc(c); err != nil && err != errHijacked {
 			errStr := err.Error()
-			if !strings.Contains(errStr, "broken pipe") && !strings.Contains(errStr, "reset by peer") &&
-				!strings.Contains(errStr, "i/o timeout") {
+			if wp.LogAllErrors || !(strings.Contains(errStr, "broken pipe") ||
+				strings.Contains(errStr, "reset by peer") ||
+				strings.Contains(errStr, "i/o timeout")) {
 				wp.Logger.Printf("error when serving connection %q<->%q: %s", c.LocalAddr(), c.RemoteAddr(), err)
 			}
 		}