We have a classic ASP site that has some pages that do some extreme string concatenation and occasionally generate the “Out of string space” (OOSS) exception. I am fixing the pages either with direct response.write calls or using a StringBuilder class from the ajaxed library. That is solving the problem.
My question is if the OOSS errors affect just that request/response thread in IIS/AppPool or does the OOSS error bring down the IIS/AppPool as a whole? IIS still seems to respond to subsequent requests, but usually we start receiving “Out of memory” errors soon thereafter.
Just looking for some inside knowledge about what OOSS does to the process as a whole and if we should recycle the AppPool immediately or is just the single request affected?
An OOSS error should only take out the thread that was handling the offending call.
One of the causes of the OOSS is low memory. It sounds like you’re getting the OOSS error as an indicator of low memory and then shortly after you are receiving the Out of Memory errors elsewhere.
For reference, the causes of the OOSS error are listed here:
Out of string space (Error 14) – MSDN