dtrace discuss - Jul 2009 - please - need a proces profiling help

Hi!

I am a total noob about dtrace but I hope it could solve my huge problem - I
have a process that synchronizes data between two Solaris 10 boxes (part of a
cluster) which should do 3 things:

1) read files from disk
2) compare files to "other side"
3) transfer differences (or all files)

The problem is that sync tome is becoming longer and longer lately without
obvious reasons (number of files to sync didn''t have any huge raise nor
network became any more saturated than before) - so I need to know which part of
processes take most time in execution.

I''ve looked through io providers but am not sure how to make a dtrace
script to get some useful data. If someone could give me pointers what to do - I
would really appreciate it.

-o.
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This message posted from opensolaris.org

You could try the Sun Studio Performance Analyzer on the process.
It should tell you where the time is being spent.

http://developers.sun.com/sunstudio/overview/topics/analyzer_index.html

    Marty Itzkowitz


On 7/17/09 5:40 PM, Okie wrote:
> Hi!
>
> I am a total noob about dtrace but I hope it could solve my huge problem -
I have a process that synchronizes data between two Solaris 10 boxes (part of a
cluster) which should do 3 things:
>
> 1) read files from disk
> 2) compare files to "other side"
> 3) transfer differences (or all files)
>
> The problem is that sync tome is becoming longer and longer lately without
obvious reasons (number of files to sync didn''t have any huge raise nor
network became any more saturated than before) - so I need to know which part of
processes take most time in execution.
>
> I''ve looked through io providers but am not sure how to make a
dtrace script to get some useful data. If someone could give me pointers what to
do - I would really appreciate it.
>
> -o.
>

Hi Martyi,

thanks for reply. I looked into sun studio performance analyzer and it seems
from quick start description that I would have to compile my replicator with
some parameters. Is that right?

If it is, then it''s a no-go since I don''t have a source. This
is a commercial product.
-- 
This message posted from opensolaris.org

No special compilation is needed.  We can show more if you compiled -g --
per source-line information, and static functions, but you would see
most functions anyway.  Try it.

    Marty

On 7/18/09 7:46 AM, Okie wrote:
> Hi Martyi,
>
> thanks for reply. I looked into sun studio performance analyzer and it
seems from quick start description that I would have to compile my replicator
with some parameters. Is that right?
>
> If it is, then it''s a no-go since I don''t have a source.
This is a commercial product.
>

> The problem is that sync tome is becoming longer and longer lately  
> without obvious reasons (number of files to sync didn''t have any  
> huge raise nor network became any more saturated than before) - so I  
> need to know which part of processes take most time in execution.
>
> I''ve looked through io providers but am not sure how to make a  
> dtrace script to get some useful data. If someone could give me  
> pointers what to do - I would really appreciate it.

Hi Okie,

The first provider I suggest you bring to bear in the profile  
provider. You
can find the documentation here:

   http://wikis.sun.com/display/DTrace/profile+Provider

A very simple script might help you get started:

profile:::profile-1001
{
	@[ustack()] = count();
}

Alternatively, the sched provider can help you understand why a  
process is
giving up the CPU:

   http://wikis.sun.com/display/DTrace/sched+Provider

Some of the examples in that chapter will be instructional.

Adam

--
Adam Leventhal, Fishworks                        http://blogs.sun.com/ahl

You may also try latencytop which is a new tool. No scripting needed :)

http://opensolaris.org/os/project/latencytop/

I believe it works for recent Solaris 10 updates, all it requires is that you
have glib2 installed from here:

http://www.sunfreeware.com/programlistintel10.html#glib

Okie wrote:
> Hi!
> 
> I am a total noob about dtrace but I hope it could solve my huge
> problem - I have a process that synchronizes data between two Solaris
> 10 boxes (part of a cluster) which should do 3 things:  
> 
> 1) read files from disk
> 2) compare files to "other side"
> 3) transfer differences (or all files)
> 
> The problem is that sync tome is becoming longer and longer lately
> without obvious reasons (number of files to sync didn''t have any
huge
> raise nor network became any more saturated than before) - so I need
> to know which part of processes take most time in execution.   
> 
> I''ve looked through io providers but am not sure how to make a
dtrace
> script to get some useful data. If someone could give me pointers
> what to do - I would really appreciate it.  
> 
> -o.

Guys,

thanks for help. Will try this and then come back with feedback.

-okie
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