PHP process crash


We experience PHP process crash and believe that the reason is SQL Server driver. The driver is used for Drupal 7 installation and the only way to reproduce it is to issue massive parallel requests while Drupal is clearing its cache. We were trying to explore the problem as deep as possible with xebug tracing to get the last PHP function call before the crash and to get native functions backtrace with Debug Diagnostics Tool as described on the PHP documentation. Results are the following:
  • Each xdebug trace of the crashed request ends with PDOStatement->execute() called for the insert query.
  • Native crash analysis reports about "the assembly instruction at php5!_efree+6a in C:\PHP\php5.dll from The PHP Group has caused an access violation exception (0xC0000005) when trying to read from memory location 0x00000000 on thread 0".
I'm attaching user dump analysis results produced by Debug Diagnostics Tool. Stack trace looks not resolved probably because of missing debug pack files for the SQL Server driver. If someone could help me to properly resolve the stack trace it would be really great.

If you need more details, please feel free to ask.

file attachments


DmitriyTrt wrote Apr 2, 2014 at 9:32 AM

One more crash analysis.