From db3dbcce3ac673113ba48967cf1d656606a41dc3 Mon Sep 17 00:00:00 2001
From: Klaus Post <klauspost@gmail.com>
Date: Fri, 29 Nov 2019 06:10:08 -0800
Subject: [PATCH] Print goroutines when shutdown hangs (#8574)

---
 cmd/http/server.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/cmd/http/server.go b/cmd/http/server.go
index 7a47c02ba..836f6bb12 100644
--- a/cmd/http/server.go
+++ b/cmd/http/server.go
@@ -19,7 +19,9 @@ package http
 import (
 	"crypto/tls"
 	"errors"
+	"io/ioutil"
 	"net/http"
+	"runtime/pprof"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -137,6 +139,13 @@ func (srv *Server) Shutdown() error {
 	for {
 		select {
 		case <-shutdownTimer.C:
+			// Write all running goroutines.
+			tmp, err := ioutil.TempFile("", "minio-goroutines-*.txt")
+			if err == nil {
+				_ = pprof.Lookup("goroutine").WriteTo(tmp, 1)
+				tmp.Close()
+				return errors.New("timed out. some connections are still active. doing abnormal shutdown. goroutines written to " + tmp.Name())
+			}
 			return errors.New("timed out. some connections are still active. doing abnormal shutdown")
 		case <-ticker.C:
 			if atomic.LoadInt32(&srv.requestCount) <= 0 {