Add setting to flush fabio buffer regardless headers (#531)

config/config.go

@@ -59,6 +59,7 @@ type Proxy struct {
 	ResponseHeaderTimeout time.Duration
 	KeepAliveTimeout      time.Duration
 	FlushInterval         time.Duration
+	GlobalFlushInterval   time.Duration
 	LocalIP               string
 	ClientIPHeader        string
 	TLSHeader             string

config/default.go

@@ -36,13 +36,14 @@ var defaultConfig = &Config{
 		},
 	},
 	Proxy: Proxy{
-		MaxConn:       10000,
-		Strategy:      "rnd",
-		Matcher:       "prefix",
-		NoRouteStatus: 404,
-		DialTimeout:   30 * time.Second,
-		FlushInterval: time.Second,
-		LocalIP:       LocalIPString(),
+		MaxConn:             10000,
+		Strategy:            "rnd",
+		Matcher:             "prefix",
+		NoRouteStatus:       404,
+		DialTimeout:         30 * time.Second,
+		FlushInterval:       time.Second,
+		GlobalFlushInterval: 0,
+		LocalIP:             LocalIPString(),
 	},
 	Registry: Registry{
 		Backend: "consul",

config/load.go

@@ -139,6 +139,7 @@ func load(cmdline, environ, envprefix []string, props *properties.Properties) (c
 	f.DurationVar(&readTimeout, "proxy.readtimeout", defaultValues.ReadTimeout, "read timeout for incoming requests")
 	f.DurationVar(&writeTimeout, "proxy.writetimeout", defaultValues.WriteTimeout, "write timeout for outgoing responses")
 	f.DurationVar(&cfg.Proxy.FlushInterval, "proxy.flushinterval", defaultConfig.Proxy.FlushInterval, "flush interval for streaming responses")
+	f.DurationVar(&cfg.Proxy.GlobalFlushInterval, "proxy.globalflushinterval", defaultConfig.Proxy.GlobalFlushInterval, "flush interval for non-streaming responses")
 	f.StringVar(&cfg.Log.AccessFormat, "log.access.format", defaultConfig.Log.AccessFormat, "access log format")
 	f.StringVar(&cfg.Log.AccessTarget, "log.access.target", defaultConfig.Log.AccessTarget, "access log target")
 	f.StringVar(&cfg.Log.RoutesFormat, "log.routes.format", defaultConfig.Log.RoutesFormat, "log format of routing table updates")

config/load_test.go

@@ -362,6 +362,13 @@ func TestLoad(t *testing.T) {
 				return cfg
 			},
 		},
+		{
+			args: []string{"-proxy.globalflushinterval", "5ms"},
+			cfg: func(cfg *Config) *Config {
+				cfg.Proxy.GlobalFlushInterval = 5 * time.Millisecond
+				return cfg
+			},
+		},
 		{
 			args: []string{"-proxy.maxconn", "555"},
 			cfg: func(cfg *Config) *Config {

docs/content/ref/proxy.globalflushinterval.md

@@ -0,0 +1,10 @@
+---
+title: "proxy.globalflushinterval"
+---
+
+`proxy.globalflushinterval` configures periodic flushing of the
+response buffer for proxied non-SSE connections. By default it is disabled.
+
+The default is
+
+    proxy.globalflushinterval = 0

fabio.properties

@@ -358,6 +358,12 @@
 #
 # proxy.flushinterval = 1s
 
+# proxy.globalflushinterval configures periodic flushing of the
+# response buffer for non-SSE connections. By default it is not enabled.
+#
+# The default is
+#
+# proxy.globalflushinterval = 0
 
 # proxy.maxconn configures the maximum number of cached
 # incoming and outgoing connections.

proxy/http_proxy.go

@@ -169,7 +169,7 @@ func (p *HTTPProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h = newHTTPProxy(targetURL, tr, p.Config.FlushInterval)
 
 	default:
-		h = newHTTPProxy(targetURL, tr, time.Duration(0))
+		h = newHTTPProxy(targetURL, tr, p.Config.Proxy.GlobalFlushInterval)
 	}
 
 	if p.Config.GZIPContentTypes != nil {