Revert "use bigger socket buffers and optimizations on idle connections" (#129)

This reverts commit d6c790e.

Author: poornas

main_linux.go

@@ -21,7 +21,6 @@ package main
 import (
 	"syscall"
 
-	"github.com/dustin/go-humanize"
 	"golang.org/x/sys/unix"
 )
 
@@ -34,16 +33,9 @@ func setTCPParameters(_, _ string, c syscall.RawConn) error {
 
 		_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
 
-		{
-			// Enable big buffers
-			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, 4*humanize.MiByte)
-
-			_ = unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_RCVBUF, 4*humanize.MiByte)
-		}
-
 		// Enable TCP open
-		// https://lwn.net/Articles/508865/ - 32k queue size.
-		_ = syscall.SetsockoptInt(fd, syscall.SOL_TCP, unix.TCP_FASTOPEN, 32*humanize.KiByte)
+		// https://lwn.net/Articles/508865/ - 16k queue size.
+		_ = syscall.SetsockoptInt(fd, syscall.SOL_TCP, unix.TCP_FASTOPEN, 16*1024)
 
 		// Enable TCP fast connect
 		// TCPFastOpenConnect sets the underlying socket to use
@@ -54,25 +46,6 @@ func setTCPParameters(_, _ string, c syscall.RawConn) error {
 		// Enable TCP quick ACK, John Nagle says
 		// "Set TCP_QUICKACK. If you find a case where that makes things worse, let me know."
 		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_QUICKACK, 1)
-
-		// The time (in seconds) the connection needs to remain idle before
-		// TCP starts sending keepalive probes
-		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, 15)
-
-		// Number of probes.
-		// ~ cat /proc/sys/net/ipv4/tcp_keepalive_probes (defaults to 9, we reduce it to 5)
-		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPCNT, 5)
-
-		// Wait time after successful probe in seconds.
-		// ~ cat /proc/sys/net/ipv4/tcp_keepalive_intvl (defaults to 75 secs, we reduce it to 15 secs)
-		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
-
-		// Set tcp user timeout in addition to the keep-alive - tcp-keepalive is not enough to close a socket
-		// with dead end because tcp-keepalive is not fired when there is data in the socket buffer.
-		//    https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/
-		// This is a sensitive configuration, it is better to set it to high values, > 60 secs since it can
-		// affect clients reading data with a very slow pace  (disappropriate with socket buffer sizes)
-		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT, 600000)
 	})
 	return nil
 }