Re: Proposed Windows-specific change: Enable crash dumps (like core files)

Craig Ringer wrote:
> On 4/10/2010 8:06 PM, Andrew Dunstan wrote:
> >
> >
> > On 10/04/2010 07:50 AM, Craig Ringer wrote:
> >>
> >> - If the crash dump handler is enabled by setting the GUC,
> >> all backends register the handler during startup or (if it
> >> proves practical) when the GUC is changed.
> >>
> >> - When the handler is triggered by the OS trapping an unhandled
> >> exception, it loads dbghelp.dll, writes the appropriate dump
> >> format to the hardcoded path, and terminates the process.
> >>
> >>
> >
> > What is the performance impact of doing that? Specifically, how does it
> > affect backend startup time?
> 
> Without testing I can't say for sure.
> 
> My expection based on how the handler works would be: near-zero, about 
> as expensive as registering a signal handler, plus the cost of reading 
> the GUC and doing one string compare to test the value. When disabled, 
> it's just the GUC test.
> 
> Is there a better mechanism to use for features that're going to be 
> unused the great majority of the time? Perhaps something that does 
> require a server restart, but doesn't have any cost at all when disabled?

We definately had trouble producing crash dumps caused by the 128 return
code problem, so I can see great value in this, if it can be done
simply.  I wonder if the 128-exit would have produced a crash file.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +