Ethereal-users: Re: [Ethereal-users] Help interpreting log file ?

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From: Arnaud Lesauvage <thewild@xxxxxxxxxxx>
Date: Fri, 10 Feb 2006 10:04:01 +0100
Hello again list !

Thanks a lot for your answers on this matter.
I had also posted this message on the comp.protocols.tcp-ip newsgroup, and someone there suggested that I set the TcpAckFrequency key to 1. The default setting is 2. With this setting, every single packet is acknowledged and the delay is gone. I'd rather have found a real fix to this problem, but this will be ok for now.

Bill Meier a �crit :
"TCP_NODELAY" should be enabled on the TCP connection to
the database on both the client and server side of the connection.
(This is also known as "disabling the Nagle Algorithm").
(Based upon your capture I can almost guarantee that TCP_NODELAY is
*not* enabled on your Database TCP connection on the server side).

The use of TCP_NODELAY is a database option for a different database server with which I'm familiar. I suggest you consult your DBA with respect to PostgreSQL.
(Also Google "database tcp_nodelay" & etc for information).

I haven't found this option in the PostgreSQL doc, but I am going to send your suggestions as well as the analysis from the NG to the PostgreSQL developers. I am sure that they will make good use of this information !

ronnie sahlberg a �crit :
The TCP stack in 10.0.0.13 is broken.
[...]
You MIGHT be able to workaround this breakage by disabling Nagle on
10.0.0.13   but this often means you also get a small degradation of
performance.

Is this equivalent to what I did when I have set TcpAckFrequency to 1 ? I think that, for WinXP's TCPIP stack at least, the nagle algorithme can only be disabled on a per-connection basis. Since I have no control over the way the psqlodbc driver and the server talk to each other, I don't know how I could chaneg this ?


Thanks to both of you for your help on this matter !
Regards,
--
Arnaud