The documentation required to diagnose child process crashes includes
If core dumps are not being saved for the child process crashes, the first step is to perform any necessary operating system and web server configuration so that core dumps are saved. Core dump configuration information is described here.
When a core dump is available, the ServerDoc tool provided with ihsdiag automates much of the work of gathering and formatting the required documentation. The user runs ServerDoc and provides the IHS installation directory and the path to the core file, and ServerDoc creates a new directory to hold the required documentation, and stores information in that new directory.
Once the ServerDoc tool has completed, the user should copy any remaining log files and configuration files used by the web server and the plug-in into the new directory, and send in the directory to IBM support.
A core dump and related information is critical for diagnosing the cause of child process crashes. Without the information, IBM support is limited to suggesting that the customer move to the current level of fixes. With the information, IBM support anticipates being able to make the following initial determination:
In cases where an IBM component crashed, the information often contains enough information to address the root cause of previously unknown problems. Even when the root cause cannot be determined from a particular core dump, the information is used to decide the next step.
In cases where a third-party component crashed, the vendor of that component will need to investigate further; IBM support is unable to diagnose problems in third-party components.
Please refer to these instructions for verifying that required support programs are installed.
Run the tool as root
to avoid any permissions problems
with reading the core file or other files, such as log files and
configuration files. (More information about the requirement to run
this tool as root
is available here.)
ServerDoc is passed three parameters for gathering crash documentation:
GatherCrashDoc
# java -jar ServerDoc.jar GatherCrashDoc /path/to/IHS /path/to/corefile
The tool creates a new directory which contains a timestamp in the name, and the crash documentation will be saved in that directory.
For this example, IHS is installed in /usr/HTTPServer
,
the core dump was written to /tmp/core
, and ihsdiag was
unpacked into /root/ihsdiag-1.1.0
# cd /tmp # java -jar /root/ihsdiag-1.1.0/ServerDoc.jar GatherCrashDoc \ /usr/HTTPServer /tmp/core Reports, log files, and configuration files have been saved to directory CrashDoc.200404121310 If you have additional log files or configuration files, copy them there before packing up the directory. Hint for packing up the directory: tar -cf CrashDoc.200404121310.tar CrashDoc.200404121310 gzip CrashDoc.200404121310.tar # ls -l CrashDoc.200404121310/ total 8136 -rw-r--r-- 1 root system 8779 Apr 12 13:10 access_log -rw-r--r-- 1 root system 7094 Apr 12 13:10 apachectl -rw-r--r-- 1 root system 3593703 Apr 12 13:10 core -rw-r--r-- 1 root system 478483 Apr 12 13:10 core_file_strings -rw-r--r-- 1 root system 14419 Apr 12 13:10 error_log -rw-r--r-- 1 root system 37141 Apr 12 13:10 httpd.conf -rw-r--r-- 1 root system 7500 Apr 12 13:10 log -rw-r--r-- 1 root system 173 Apr 12 13:10 report
The next step is to copy any other web server or plug-in configuration files and logs into the new CrashDoc directory. Here is a list of files to copy if they are being used:
The last step is to pack up and compress the documentation directory using tar and gzip. The easiest way is to cut and paste the messages displayed by ServerDoc previously which showed the tar and gzip commands to use.
# tar -cf CrashDoc.200404121310.tar CrashDoc.200404121310 # gzip CrashDoc.200404121310.tar
root
requirementroot
or by the web server user id
(e.g., nobody
or www
).
If the web server is started as root
, the permissions
on generated core files and log files and configuration files can be
changed to allow a non-root
user to run the crash
documentation tool.
If the web server is not started as root
, there are no
such concerns, and the crash documentation tool may be run by the user
id which starts the web server.
If the tool is run as non-root
and it is unable to
gather the required information, permissions on the core file or other
files can be changed and the tool may be run again. It may not be
possible to determine if this problem occurred until the documentation
has been analyzed by IBM HTTP Server support.