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--- litespeed_wiki:php_503_error [2015/02/02 17:32]
Jackson Zhang [4. Analyze Core File with GNU Debugger]
+++ litespeed_wiki:php_503_error [2015/02/27 16:07]
Jackson Zhang [3. Enable Core Dump (or just turn off opcode caching)]
@@ Line 60: / Line 60: @@
 Your Redhat/Centos system may already use ABRT(Automatic Bug Reporting Tool) tool to generate core dump files. In this case, core files may be located at /var/spool/abrt/.  ABRT configuration files are normally located at /etc/abrt/.  Please ensure the setting   "ProcessUnpackaged = yes" in /etc/abrt/abrt-action-save-package-data.conf to enable the core dump, otherwise core file may not be generated even the web server error log says so.  If you want to disable core file dump after the debugging, simply change "ProcessUnpackaged" setting back to "no".
+core_pattern is used to specify a core dumpfile pattern name.
+  cat /proc/sys/kernel/core_pattern
+which shows you the pattern template for the output filename.
+If the first character of the pattern is a '|', the kernel will treat the rest of the pattern as a command to run.  The core dump will be written to the standard input of that program instead of to a file.
+By default, /proc/sys/kernel/core_pattern contains core string and kernel produces core.* files in crashed process's current directory.
+Abrt’s C/C++ hook overrides this with:
+  |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t e
+which results in kernel calling abrt-hook-ccpp
 **Note:** As noted below, opcode caches are frequently a cause of PHP crashes. If you find your PHP crashed, you may want to try turning off any opcode caching you have. This is addressed further [[litespeed_wiki:php_503_error#opcode_caches_apc_xcache_eaccelerateor|below]].