Hi Marc,
The .NET client has a bug that prevents use of persistent MySQL connections. The application is already cached up the wazoo.

Where would I look in the kernel to see if it is rejecting the connections as opposed to MySQL? Or is this just unlikely given that the hardware is fairly robust?
Thanks,

 - yba


On Mon, 2 Feb 2009, m...@swiftouch.com wrote:

Date: Mon, 2 Feb 2009 18:28:21 +0200 (IST)
From: m...@swiftouch.com
To: Jonathan Ben Avraham <y...@tkos.co.il>
Cc: Gilad Ben-Yossef <gi...@codefidence.com>, ILUG <linux-il@cs.huji.ac.il>
Subject: Re: [YBA] TCP connection rate

Hi all

Without delving into the stack behaviour, I would try the (potentially) cheaper route - is there a possibility of amalgamating queries to the database, thereby reducing the per second metric? Or - perish the thought (caveat emptor, I am not acquainted with the app) - caching replies at the client?

I am not sure the netstat trick can work in this case - both since (as YBA noted) the connexions are brief and because netstat deals with connections very late in their lifecycle. I am not sure how connexions pending on the stack would show up.

M

---MAV
Marc. Volovic
+972-54-467-6764
m...@swiftouch.com
Sent from my iPhone

On Feb 2, 2009, at 5:06 PM, Jonathan Ben Avraham <y...@tkos.co.il> wrote:

Hi Gilad,
Thanks. The problem is that the connections are exceedingly short-lived. By the time I type in "netstat -na" already 1000 of them have come and gone.

- yba


On Mon, 2 Feb 2009, Gilad Ben-Yossef wrote:

Date: Mon, 02 Feb 2009 16:29:23 +0200
From: Gilad Ben-Yossef <gi...@codefidence.com>
To: Jonathan Ben Avraham <y...@tkos.co.il>
Cc: ILUG <linux-il@cs.huji.ac.il>
Subject: Re: [YBA] TCP connection rate
Jonathan Ben Avraham wrote:

Dear list members,
What limits the rate that the Linux kernel TCP stack can accept new connections? How is that rate related to the rate that the application listening on a port can handle the connections? That is, if I try to connect and get ECONNREFUSED is there a way for me to know if I got it because the kernel could not handle the connection rate or if I got it because I had more connection attempts than the backlog parameter of my listen() call? In other words, do I need to tune the kernel or the application (MySQL) for the desired high connection rate and how would I know?

Just check what the value of the backlog parameter is and then use netstat to watch the application connections when you get ECONNREFUSED error. If the number of connections in netstat is equal (or at least very close to) the backlog parameter then it's the backlog parameter, otherwise it's something else.

Gilad



--
EE 77 7F 30 4A 64 2E C5  83 5F E7 49 A6 82 29 BA    ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

_______________________________________________
Linux-il mailing list
Linux-il@cs.huji.ac.il
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il

--
 EE 77 7F 30 4A 64 2E C5  83 5F E7 49 A6 82 29 BA    ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
     - y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

_______________________________________________
Linux-il mailing list
Linux-il@cs.huji.ac.il
http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il

Reply via email to