Use of flags (Z) NODELAY on GT.M

[Valeriu Gontia]

I have noticed that the use of the flag in NODELAY service xinetd,
get a huge gain in speed during multiple calls
(in the cycle) from the client application.

service mactivate
{
     flags = NODELAY
     disable = no
     type = UNLISTED
     port = 1959
     socket_type = stream
     wait = no
     user = root
     server = / usr/local/gtm60/zmactivate
}

For example (VB):

Private Sub Command3_Click ()
Dim Ret As String
For i = 1 To 1000
Ret = Ret & m.Xecute ("w $zv") & " "
Next i
MsgBox Ret
End Sub

I get a full response from the server in about 6 seconds

If this method with the native socket GT.M:

o tcpdev: (ZLISTEN = port_ ": TCP": NODELIMITER: ZNODELAY: ATTACH = "listener"): timeo: "SOCKET"

even faster - about 1.5 seconds!

How justified is this? This puts an extra burden on the system or not?

Thank you.

[Sam Habiel]

This disables the Nagle Algorithm on the TCP level. Look that up. In general, you should not disable it unless you are sure that is what you want to do. A better solution is to rewrite your sends so that they are not flushed until the end.

Sam