@blah238's very nice answer to Porting Avenue code for Producing Building Shadows to ArcPy/Python for ArcGIS Desktop? reminded me of all the time I've spent over the past two years battling against the dreaded geoprocessor memory leak in ArcGIS Desktop.

I only have personal experience of problems with version 9.3.1, but there are numerous threads on the ESRI support pages (e.g. here, here) which suggest that the problem goes back to at least v9.1. blah238's answer and this thread indicate that the problem still isn't fixed at v10.

I know that workarounds are possible, usually involving the use of subprocesses to force the gp to release the memory it's hogging, but they're clunky and often very slow.

This question isn't meant as an attack on ESRI, but I'd be really interested to know:

Why has this problem proved so difficult to fix?

For my work at least, it's a major issue and one that's pushed me away from using ArcGIS for spatial modelling. This has been a great learning experience, but I'm surprised that fixing the problem isn't higher on ESRI's priority list.

  • I assume that question is better located at esris forums/channels, isn´t it? You won´t get any answer here unless some ESRI-supporter is here. Commented Oct 29, 2015 at 7:45

1 Answer 1


This is actually worse in Arcpy to be honest, and we've struggled for ages to deal with it. We set off processing 400 identical geometries, doing an identical set of processes. It performed the first set in 3 seconds, and the last in 4 minutes, getting progressively slower through the set. When ESRI 'fixed' it in SP1, it introduced new problems, when they 'fixed' it in SP2, it stopped AggregatePoints functionality working, in SP3 it was worse.

Apparently, it is getting fixed in 10.1

We improved performance 20 fold, by simply turning off garbage collecting

  • Interesting, thanks. When I was struggling with this, I tried all kinds of garbage collector options without much luck, but I don't think I ever tried turning it off completely. Definitely one to remember!
    – JamesS
    Commented Feb 14, 2012 at 10:14
  • Worked a treat, to speed it up, the memory still leaked, but the gain in performance made the leak that much easier to swallow. Bad ESRI...
    – Hairy
    Commented Feb 14, 2012 at 13:06

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