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(mysql.info)Communication errors

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Communication Errors / Aborted Connection
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Starting with `MySQL 3.23.40' you only get the `Aborted connection'
error of you start `mysqld' with `--warnings'.

If you find errors like the following in your error log.

     010301 14:38:23  Aborted connection 854 to db: 'users' user: 'josh'

Note: Error log.

This means that something of the following has happened:

   * The client program did not call `mysql_close()' before exit.

   * The client had been sleeping more than `wait_timeout' or
     `interactive_timeout' without doing any requests. Note: SHOW
     VARIABLES.

   * The client program ended abruptly in the middle of the transfer.

When the above happens, the server variable `Aborted_clients' is
incremented.

The server variable `Aborted_connects' is incremented when:

   * When a connection packet doesn't contain the right information.

   * When the user didn't have privileges to connect to a database.

   * When a user uses a wrong password.

   * When it takes more than `connect_timeout' seconds to get a connect
     package.

Note that the above could indicate that someone is trying to break into
your database!

Note: SHOW VARIABLES.

Other reasons for problems with Aborted clients / Aborted connections.
   * Usage of duplex Ethernet protocol, both half and full with Linux.
     Many Linux Ethernet drivers have this bug. You should test for
     this bug by transferring a huge file via ftp between these two
     machines. If a transfer goes in burst-pause-burst-pause ... mode
     then you are experiencing a Linux duplex syndrome. The only
     solution to this problem is switching of both half and full
     duplexing on hubs and switches.

   * Some problem with the thread library that causes interrupts on
     reads.

   * Badly configured TCP/IP.

   * Faulty Ethernets or hubs or switches, cables ... This can be
     diagnosed properly only by replacing hardware.

   * `max_allowed_packet' is too small or queries require more memory
     than you have alloacated for `mysqld'. Note: Packet too large.