[ka-Map-users] Re: kaMap - resource hogger?

[ramesh karra]

This problem occurred again today and when I looked at
the process statistics, it showed that firefox is
taking almost 99% of the CPU! Memory usage was OK.

So, it looks like this is not a memory leak related
issue but CPU hogging issue.

Is it possible that some event is occurring
constantly?
How do I debug this? Do I need to use strace/truss
equivalents on windows? Is there any easier way?

Thanks
Ramesh

--- ramesh karra <karrarm at yahoo.com> wrote:

> Thanks for the quick and detailed reply paul!
> 
> I suspected memory leak/garbage collection as the
> issue but I was not sure if this the case with kaMap
> or AJAX in general. 
> 
> Are there any tools(like DOM Inspector) available to
> see what objects are currently (allocated) in the
> memory? 
> 
> I am using firefox and not IE. Next time, I will
> keep
> an eye on the amount of memory in use by firefox.
> 
> My map data is relatively small and is static. So, I
> do not expect the mapserver/kaMap to create tiles
> again and again.
> 
> Thanks again,
> Ramesh
> 
> 
> 
> --- Paul Spencer <pspencer at dmsolutions.ca> wrote:
> 
> > Ramesh,
> > 
> > there is a general problem with ajax applications
> > that involves how  
> > browsers garbage collection memory.  It is
> possible,
> > and in fact very  
> > easy, to set up situations where the browser is
> > unable to release  
> > memory of objects that have no references to them.
> 
> > This is generally  
> > called a memory leak.  It is highly likely that
> > ka-Map has such  
> > memory leaks because I don't really understand how
> > to avoid them.   
> > AJAX-related leaks are much worse in IE than
> > firefox, so if you are  
> > running IE and ka-Map then when your system
> becomes
> > slow, check your  
> > task manager to see how much memory the IE process
> > is using.
> > 
> > There is no way that I know of to detect/eliminate
> > leaks other than  
> > to manually inspect the code and try to figure out
> > where the leaks  
> > are happening.  Due to the nature of how leaks
> > happen (closures etc),  
> > this is a very difficult task.  While I do try to
> > resolve leaks as  
> > best as possible, it is quite likely that they are
> > still in there.
> > 
> > The second issue that I will bring up is that
> > MapServer doesn't  
> > perform that well on my laptop, mostly because
> > laptops have  
> > harddrives with low RPMs compared to
> desktop/server
> > systems and  
> > rendering maps (at least for mapserver) is a
> > disk-intensive process  
> > (reading spatial data for a large image, writing
> the
> > resulting image  
> > to the disk, then reading it again to produce
> > tiles), and even when  
> > tiles are generated, they have to be read off
> disk.
> > 
> > The third issue is that running the client and
> > server on the same  
> > machine tends to produce resource competition. 
> Your
> > machine is a  
> > single processor and it can only do one thing at a
> > time.
> > 
> > But mostly I suspect memory leaks if it is
> impacting
> > other  
> > applications :)
> > 
> > Cheers
> > 
> > Paul
> > 
> > On 27-Apr-06, at 1:53 AM, ramesh karra wrote:
> > 
> > > Hi,
> > >
> > > I have installed mapserver and kaMap on my
> > laptop(IBM
> > > T42 with Intel pentium 1.7GHz and 512MB RAM)
> after
> > > loading my map and using it for some time, the
> > system
> > > becomes very slow(especially Microsoft Outlook).
> > When
> > > I closed my browser, system recovered and the
> > Outlook
> > > was back to normal.
> > >
> > > I am assuming this is related to kaMap and not
> > > mapserver because mapserver is running all the
> > time,
> > > even when the browser is closed. Ofcourse, it
> > still
> > > possible that the mapserver is hogging resources
> > when
> > > kaMap is active and not when it is gone.
> > >
> > > Are there any known resource hogging issues with
> > kaMap
> > > or  mapserver?
> > >
> > > Thanks
> > > Ramesh
> > >
> > >
> __________________________________________________
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>
+-----------------------------------------------------------------+
> > |Paul Spencer                          
> > pspencer at dmsolutions.ca   |
> >
>
+-----------------------------------------------------------------+
> > |Applications & Software Development              
>  
> >              |
> > |DM Solutions Group Inc                
> > http://www.dmsolutions.ca/|
> >
>
+-----------------------------------------------------------------+
> > 
> > 
> > 
> > 
> > 
> 
> 
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