I trying to track down the cause of an OutOfMemory for a website. This site has ~12,000 .aspx pages and the last time it crashed I captured a memory dump using adplus.

After some investigation I found a lot of heap fragmentation, there are around 100MB of Free blocks which can't be assigned. Digging deeper one of the Large Object Heaps is fragmented and the causes seems to be String interning as described [here][1]

Could this be caused by the number of pages in the site? As they are all compiled they sit in memory and by looking at the dump they are interned and PINNED which I think means they stick around for a while.

I would find this odd as there are many sites with more pages, but dynamic compilation could account for the growth in memory.

What other methods are there for finding the cause of the memory leak? I have tried to capture a dump using adplus in hang mode but this fails and the IIS worker process get recycled.

[1]: • http://stackoverflow.com/questions/686950/large-object-heap-fragmentation