Memory leak -- doesn't close raster files

[leftys]

When used in FCGI configuration, I observe raising memory usage of mapserv processess. lsof shows that mapserver still has opened all the tiff files served since it's start. Memory usage goes as high as 100MB and depends on the total number of layers served.

Mapserv 5.6.5, Gdal 1.6.3

[leftys]

Happens on 6.0.1 as well.

[sdlime]

Hoping Frank is available to comment... Steve CC'ing: @warmerdam

[aboudreault]

Try to use that config if you want gdal to always close its raster files:

LAYER
...
PROCESSING "CLOSE_CONNECTION=ALWAYS"
...
END

On 12-07-13 10:53 AM, leftys wrote:

When used in FCGI configuration, I observe raising memory usage of mapserv processess. lsof shows that mapserver still has opened all the tiff files served since it's start. Memory usage goes as high as 100MB and depends on the total number of layers served.

Mapserv 5.6.5, Gdal 1.6.3

---

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#4389

[dmorissette]

I believe rasters have CLOSE_CONNECTION=DEFER by default. Perhaps try CLOSE_CONNECTION=ALWAYS if you are working with large numbers of raster images and cannot afford the overhead of keeping them open (performance vs memory usage tradeoff)

[dmorissette]

Ah, I see aboudreault already commented the same thing :)

[sdlime]

Can this be closed as invalid, anyone? Steve

[tbonfort]

Yes, I believe this is working as expected. A future enhancement might be to use a global connection pool with a fixed capacity and a LRU strategy for closing unused connections.