trace over network is supported?

trace over network is supported?

[Masami Hiramatsu]

Hi,

As far as I know, systemtap still doesn't support
tracing over network (remote tracing), does it?
If so, is there any plan to support it?

Thank you,

-- 
Masami HIRAMATSU
2nd Dept. Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: trace over network is supported?

[Frank Ch. Eigler]

Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> writes:

> As far as I know, systemtap still doesn't support tracing over
> network (remote tracing), does it?

One can invoke stap over an ssh or similar connection, so to that
extent, "yes, it can.".  What do you mean exactly?

> If so, is there any plan to support it?

Actually, we are in the planning stages of two or three new orthogonal
efforts in this area.

- FChE

Re: trace over network is supported?

[Masami Hiramatsu]

(2010/09/09 23:21), Frank Ch. Eigler wrote:
> Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> writes:
> 
>> As far as I know, systemtap still doesn't support tracing over
>> network (remote tracing), does it?
> 
> One can invoke stap over an ssh or similar connection, so to that
> extent, "yes, it can.".  What do you mean exactly?

Yeah, I know about tracing over ssh connection, but
that is too heavy to record high-freq system events
(e.g. systemcalls).

I meant that something like trace-data listener and
sender over UDP or TCP.

Thank you,

>> If so, is there any plan to support it?
> 
> Actually, we are in the planning stages of two or three new orthogonal
> efforts in this area.
> 
> - FChE

trace over network is supported?

[Tim Beaulen]

On Fri, Sep 10, 2010 at 8:48 AM, Masami Hiramatsu
<masami.hiramatsu.pt@hitachi.com> wrote:
>
> Yeah, I know about tracing over ssh connection, but
> that is too heavy to record high-freq system events
> (e.g. systemcalls).
>
> I meant that something like trace-data listener and
> sender over UDP or TCP.
>


You can use bash redirection too I guess.
example: put all the stap output to a tcp connection:
stap ... &> /dev/tcp/hostname/port

Re: trace over network is supported?

[Frank Ch. Eigler]

Hi, Masami -

> > One can invoke stap over an ssh or similar connection, so to that
> > extent, "yes, it can.".  What do you mean exactly?
> 
> Yeah, I know about tracing over ssh connection, but
> that is too heavy to record high-freq system events
> (e.g. systemcalls).
>
> I meant that something like trace-data listener and
> sender over UDP or TCP.

If the heaviness comes from the encryption provided by ssh, then one
can tie stap straight to tcp/udp sockets with wrappers like netcat.
Beyond some copy-elimination a la splice(2), do you think there is
much to be done?

- FChE