Problems and Common Errors
**************************

 to
some common problems.

How to Determine What Is Causing Problems
=========================================

When you run into problems, the first thing you should do is to find out
which program / piece of equipment is causing problems:

    normally be checked by
          pressing Caps Lock. If the Caps Lock light doesn't change you
          have to replace your keyboard.  (Before doing this, you
          should try to reboot your computer and check all cables to
          the keyboard.)

        - The mouse pointer doesn't move.

        - The machine doesn't answer to a remote machine's pings.

        - Different, unrelated programs don't behave correctly.

        - If your system rebooted unexpectedly (a faulty user level
          program should *never* be able to take down your system).

      your
     operating system that could likely solve your problems.  Check
     also that all your libraries (like glibc) are up to date.

     It's always good to use a machine with ECC memory to discover
     memory problems early!

   * If your keyboard is locked up, you may be able to fix this by
     logging into your machine from another machine and execute
     `kbd_mode -a' on it.

   * Please examine your system log file (/var/log/messages or similar)
     for reasons for your problems.  If you think the problem is in
     MySQL then you should also examine MySQL's log files. *Note Binary
     log::.

   * If you don't think you have hardware problems, you should try to
     find out which program is causing problems.

     Try using `top', `ps', `taskmanager', or some similar program, to
     check which program is taking all CPU or is locking the machine.

   * Check with `top', `df', or a similar program if you are out of
     memory, disk space, open files, or some other critical resource.

   * If the problem is some runaway process, you can always try to kill
     it. If it doesn't want to die, there is probably a bug in the
     operating system.

If after you have examined all other possibilities and you have
concluded that it's the MySQL server or a MySQL client that is causing
the problem, it's time to do a bug report for our mailing list or our
support team.  In the bug report, try to give a very detailed
description of how the system is behaving and what you think is
happening. You should also state why you think it's MySQL that is
causing the problems.  Take into consideration all the situations in
this chapter. State any problems exactly how they appear when you
examine your system. Use the 'cut and paste' method for any output
and/or error messages from programs and/or log files!

Try to describe in detail which program is not working and all symptoms
you see!  We have in the past received many bug reports that just state
"the system doesn't work".  This doesn't provide us with any
information about what could be the problem.

If a program fails, it's always useful to know:

   * Has the program in question made a segmentation fault (core
     dumped)?

   * Is the program taking up the whole CPU? Check with `top'. Let the
     program run for a while, it may be evaluating something heavy.

   * If it's the `mysqld' server that is causing problems, can you do
     `mysqladmin -u root ping' or `mysqladmin -u root processlist'?

   * What does a client program say (try with `mysql', for example)
     when you try to connect to the MySQL server?  Does the client jam?
     Do you get any output from the program?

When sending a bug report, you should of follow the outlines described
in this manual. *Note Asking questions::.

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