Re: More on lost of memory of aolserver process

On Sun, 16 Oct 2005 05:21:17 -0700
Gustaf Neumann wrote:
> i have written the following script to help to find
"application level leaks"

and later
> If the numbers don't change significantly, it is highly
likely that
> there is a c-level memleak involved and
> it is not an application problem (oacs, dotlrn).


Hello everyone,

I hope nobody minds me bumping this old thread. Gustaf, I
used your script on a production server that appears to be
leaking memory. Can you please help me interpret it?

This was the total at startup
TOTAL: pid 10686 vsz 592489 namespaces 543 vars 96 var_bytes
10118 array_elements 313 cmds 266 procs 4511

then just before the crash
TOTAL: pid 10686 vsz 1112509 namespaces 543 vars 86
var_bytes 8771 array_elements 256 cmds 266 procs 4469
unable to alloc 495960171 bytes

Would you consider the less than double "vsz"
figure a significant change? Is it of any significance that
the other values decreased (vars var_bytes etc)?
So would this suggest a C-level or application-level
problem?

The strange thing about this particular case is that the
developers tell me that "nothing changed" on this
server in quite some time. And yet it mysteriously started
crashing last week.

many thanks for any assistance

Brian Fenton


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On 2007.10.05, Fenton, Brian <Brian.FentonQUEST.IE> wrote:
> unable to alloc 495960171 bytes

What does your application do that it tries to request 495MB
of memory
in one shot?

I smell an [exec] ...

-- Dossy

-- 
Dossy Shiobara              | dossypanoptic.com | http://dossy.org/
Panoptic Computer Network   | http://panoptic.com/
  "He realized the fastest way to change is to laugh at
your own
    folly -- then you can let go and quickly move on."
(p. 70)


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Hi Brian,


Fenton, Brian schrieb:
> I hope nobody minds me bumping this old thread. Gustaf,
I used your script on a production server that appears to be
leaking memory. Can you please help me interpret it?
>   
> This was the total at startup
> TOTAL: pid 10686 vsz 592489 namespaces 543 vars 96
var_bytes 10118 array_elements 313 cmds 266 procs 4511
>
> then just before the crash
> TOTAL: pid 10686 vsz 1112509 namespaces 543 vars 86
var_bytes 8771 array_elements 256 cmds 266 procs 4469
> unable to alloc 495960171 bytes
>   
well the script was written to detect, if someone adds
variables into 
namespaces, or
appends permanently to variables, which are not reclaimed
during cleanup 
of a
connection. This is what i called "application level
leaks".

in your case, this does not seem to be the case (no
additional name 
spaces or vars, all figures
are rather less than at start-time).

The growth in vsz is not good (but not unusual) but the
size
of the alloc is something to worry.

Growth of vsz might be due to fragmentation of memory (zippy
is optimized
for minimal locks, not minimal memory footprint) or due to
the number
of threads you are using (maybe there were less threads at
startup time
than on crash time?)
> Would you consider the less than double "vsz"
figure a significant change? Is it of any significance that
the other values decreased (vars var_bytes etc)?
> So would this suggest a C-level or application-level
problem?
>   
The main question is: why does it try to allocate 500MB?
what was the last request?
do you  use some image libraries?
> The strange thing about this particular case is that
the developers tell me that "nothing changed" on
this server in quite some time. And yet it mysteriously
started crashing last week.
>   
if the allocation of 500MB sounds for your apps unusual to
you,
i would suggest to try to figure out, what happens here in
the last
request in deail.

Hope this helps

-gustaf neumann


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