Microsoft VBScript runtime error '800a0006'
OverflowSo with some pages still happily banging away (including pages with ADO etc), I was forced to conclude it wasn't a complete ASP / IIS meltdown, but something specific. Anyway, an IISRESET later, everything was cruising nicely once more.
30 minutes later - it's back (and where was this error in UAT!?). Another IISRESET and things are happy once more. Some further investigation of a failing page showed that it was crashing while calculating the number of rows needed to return some data (e.g. RecordRows = NumRecords / RecordsPerRow). No divide by zero's or conspicuous problems here either.... Re-create the app_pool and site, check the settings are sane - but it all looks good.
10 minutes later - its gone again. Starting to get worried now, I check some more failed pages. Again failing at points where it is doing calcs.... I strip out the calculation and the page loads further... until the next calc. Changing the calc to be something basic like '1 / 0.2' still causes failure. In fact a page with just:
Dim myNum
myNum=(1 / 0.2)
still causes failure... Oddness.
Some rummaging around the 'net showed a few others with a similar errors, but not a solution (most errors seemed to be coding bugs or people suggesting coding solutions). One site eventually made mention of dragging out a MS engineer to investigate a similar issue.... Apparently there was a bug with ASP (vbscript) on II6 (Windows 2003) and the C run-time checking for errors in a floating point register, but never actually resetting the error condition - meaning one floating point error takes down the site (!) Apparently the engineer wrote some code to address their issue - and because the engineer was able to resolve it on-site, MS wasn't going to make it a mainstream patch...
Some further searching of the Microsoft site for variants of ASP, IIS, Window 2003, floating point etc, eventually lead to KB955536 ( http://support.microsoft.com/kb/955536 ) - a hotfix.
After a few deep breaths, I installed the hotfix on one of our servers (thank god for redundant servers) and crossed my fingers.....
A week later, the unpatched server had been iisreset many, many times (ended up writing a powershell script to do this), but the patched server had been rock-solid, with no side-effects shown. So the hotfix was put onto the second server.
Two months on, both servers are still completely happy and very solid - it has actually made the upgrade from Windows 2000 worthwhile... But I would have preferred a smoother upgrade :/
