Strange map draw issue

[Steve Hall]

Thanks Steve,

I suspect it must be a data or config based issue as the same server / 
mapserver / web server is used (heavily) in other configurations with no 
sign of this problem.  It's just this map file & database with the issue.

Steve H


Stephen Woodbridge wrote:

> Steve,
>
> How is your server/mapscript/etc configured. It sounds like you could 
> possibly getting mapscript thread corruption or something similar to 
> that.
>
> -Steve W
>
> Steve Hall wrote:
>
>> Sorry Ed, I must have forgotten to put that part in my email.
>>
>> Yes, a simple refresh of the same map will, 9 times ot of 10, get rid 
>> of the garbage.  But then at a random interval it will reappear (but 
>> will be different garbage).
>>
>> It's kind of hard for me to "post" the entire app, or allow access, 
>> right now i'm afraid so I appreciate it may be hard for anyone to 
>> help, I as just fishing for ideas really!
>>
>> Thanks,
>>
>>
>> Steve
>>
>>
>> Ed McNierney wrote:
>>
>>> Steve -
>>>  
>>> I actually was asking if the output changed if the SAME map was 
>>> refreshed - don't zoom in, out, or pan, just refresh the 
>>> image/reload the page.  Does the same image request always return 
>>> the same image?
>>>  
>>>     - Ed
>>>
>>> Ed McNierney
>>> President and Chief Mapmaker
>>> TopoZone.com / Maps a la carte, Inc.
>>> 73 Princeton Street, Suite 305
>>> North Chelmsford, MA  01863
>>> ed at topozone.com
>>> (978) 251-4242
>>>
>>>
>>> ------------------------------------------------------------------------ 
>>>
>>> *From:* Steve Hall [mailto:steve.hall at mercatorgeosystems.co.uk]
>>> *Sent:* Thursday, September 14, 2006 10:39 AM
>>> *To:* Ed McNierney
>>> *Cc:* MAPSERVER-USERS at LISTS.UMN.EDU
>>> *Subject:* Re: [UMN_MAPSERVER-USERS] Strange map draw issue
>>>
>>> Hi Ed,
>>>
>>> Thanks for this.  I may check my label columns in the database for 
>>> NULLs and replace them with an empty string ('') instead.   It looks 
>>> like a classic 'null' issue doesn't it?
>>>
>>> Yup - zoom in, zoom out, pan etc and the garbage generally just 
>>> disappears, or changes its 'content'.   Often the angle is the same 
>>> (suspicious) but sometimes not.....  There aren't any features on 
>>> the angles so i'm not sure if it's a labelling issue or not.  Plus 
>>> the problem only occurs about 1 in 20 or so map draws so is kind of 
>>> hard to get a definite problem case.
>>>
>>> Checkout these additional ones :
>>>
>>> http://demo.mercatorgeosystems.co.uk/tmp/1158243616324003.png
>>>
>>> And just to prove it's not all CA....  ;-)
>>>
>>> http://demo.mercatorgeosystems.co.uk/tmp/1158244089248601.png
>>> http://demo.mercatorgeosystems.co.uk/tmp/1158244147717403.png
>>>
>>> Thanks Ed,
>>> Steve
>>>
>>>
>>> Take a
>>> Ed McNierney wrote:
>>>
>>>> Steve -
>>>>  
>>>> Well, just about anything in California is a little odd.....
>>>>  
>>>> Are you saying that if you simply refresh the image and re-draw the 
>>>> exact same map you'll see this line of text change?  That's 
>>>> puzzling.  I would speculate that it's a (garbage) text label for 
>>>> some garbage feature - there's some feature that's defective in 
>>>> both location and label (attributes messed up) and that feature is 
>>>> being labeled.
>>>>  
>>>> The first thing I'd try is to eliminate layers from the image, 
>>>> testing until the garbage goes away.  That could identify the 
>>>> offending layer; if there are multiple classes in that layer, use 
>>>> the same system to identify which class it is.  Then see if that 
>>>> says anything helpful.
>>>>  
>>>>     - Ed
>>>>
>>>> Ed McNierney
>>>> President and Chief Mapmaker
>>>> TopoZone.com / Maps a la carte, Inc.
>>>> 73 Princeton Street, Suite 305
>>>> North Chelmsford, MA  01863
>>>> ed at topozone.com
>>>> (978) 251-4242
>>>>
>>>>
>>>> ------------------------------------------------------------------------ 
>>>>
>>>> *From:* UMN MapServer Users List 
>>>> [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] *On Behalf Of *Steve Hall
>>>> *Sent:* Thursday, September 14, 2006 9:22 AM
>>>> *To:* MAPSERVER-USERS at LISTS.UMN.EDU
>>>> *Subject:* [UMN_MAPSERVER-USERS] Strange map draw issue
>>>>
>>>> Hi All,
>>>>
>>>> I've been using Mapserver for a while now, in a variety of 
>>>> situations, but am seeing a slightly strange behaviour in one of my 
>>>> setups.  Basically i'm getting a line of 'garbage' being drawn 
>>>> across the generated map image.
>>>>
>>>> A sample of what I mean is here :
>>>>
>>>> http://demo.mercatorgeosystems.co.uk/tmp/1158239461914994.png
>>>>
>>>> There is no road feature or other line that should be there, and if 
>>>> I redraw the map the line of garbage will either disappear or 
>>>> change in either length or 'content'.  It doesn't appear all the 
>>>> time, but certainly enough to be annoying.
>>>>
>>>> My MapServer version is 4.8.1, running with Apache 1.3.31 on Fedora 
>>>> Core 4.  I've got several other MapServer based configurations on 
>>>> this setup and they're all working fine.   The data source in 
>>>> question is an Oracle 10g (10.1) database which is also used for 
>>>> other systems and seems fine.....
>>>>
>>>> Weird eh?  Any suggestions much appreciated!
>>>>
>>>> Thanks,
>>>> Steve H
>>>>