interesting OutOfMemoryException with StringBuilder

Question

I have the need to continuously build large strings in a loop and save them to database which currently occasionally yields an OutOfMemoryException.

What

Answer 1

With the sizes you mention you are probably running into Large Object Heap (LOH) fragmentation.

Reusing StringBuilder objects is not a direct solution, you need to get a grip on the underlying buffers.
If possible, calculate or estimate the size beforehand and pre-allocate.

And it could help if you round up allocations, let's say to multiples of 20k or so. That could improve reuse.