WebGIS Discussions

[dal]

Dear All,

We have recently installed the new WebMap 2015 EP05. We are using WebMap-API for Map-Preparation. For some use cases maps are generated as zipped svg-files (svgz). Therefore we have a web.config-File in the GWMCache-Folder that defines that svgz-values need to be decompressed using the IIS-Tool URLRewrite. However, since EP05 is installed, the web.config file gets deleted automatically as soon as map-images get stored in GWMCache. When setting the option “Read-Only” on file level for the web.config-File, it does no longer get deleted. This is a viable workaround.

However, since in the Release Notes of EP05 it is written that MapServer-Manager have been developed “from scratch” we assume, that the observed behavior is possibly linked to the newly developed mapserver manager.

Has anybody encountered or heard of a similar behavior? And has anybody an idea what might causing this behavior?

Regards,

Dominik

[jan.neumann]

Hi Dominik,

WebMap probably does not take care of user's content in the cache folder. And it sounds surprising that it left web.config file intact in previous versions. The Cache folder is automatically populated and deleted by MapServer.

Setting read-only flag on the web.config sounds like a good workaround.

Jan

[dal]

Hi Jan,

However, this seems to be a new behavior of WebMap running on EP05; With WebMap 2015 EP04 (as well as older versions of WebMap as e.g. 2014) we've never encountered anything similar. 

Regards,

Dominik

[jan.neumann]

Yes, there were many changes and I don't exclude that it behaved differently. However I cannot provide any details of the internal changes as I don't know them. It could be that the older WebMap kept an array list with the file names and this mechanism was removed in order to improve memory management and replaced by bulk folder content disposal.

Let's see if other users here will participate in this discussion.

[dal]

Jan, thank you for your judgment. 

Let's see if one of the developers join the discussion 

[Anonymous]

Just FYI:

I am not a WebMap Developer, but I supported (and still do some support) WebMap since 1999.  In the past, I know for sure the files deleted from the Cache Share were the output image files (.png, .jpg, .cgm, .svg, .svgz, etc.) and the .mss files. While performing support for WebMap, there were many times where I needed to save an output image, so I would copy it to a .sav file or some other extension and leave it in the Cache Folder, and it was not deleted – ever.  I could count on it staying there.

[lukasz.baraniak · Accepted solution]

The original code of the file cleaner routine in the original Map Server Manager since WebMap 6.1 up to 15 EP05 was using {*.* as its file filter. There was no array and no other magic. After the rewrite the filter lost its opening bracket due to a typo and now kills all files instead of the ones that look as though they were generated by WebMap. I suspect gremlins for the typo

Nevertheless using the WebMap's Cache folder as storage for something else than its own files seems like a bad idea from the start and worked only based on pure luck.

As a workaround for the web.config file being deleted, you might also want to consider putting the Cache folder as a virtual sub-folder of another virtual directory in IIS and putting the web.config in the parent's physical location. This might work better if the Map Server Manager decides to also remove read-only attributed files sometime in the future

[dal]

Thanks a lot for these great explanations behind the MapSvr-Scenes.