Use MyTop to monitor threads and overall performance of MySQL 3.22.x, 3.23.x and 4.x. It will run on most Unix systems (and Mac OS X). Version 0.7+ will run on Windows.
The mytop display screen is really broken into two parts. The top 4 lines (header) contain summary information about your MySQL server. For example, you might see something like:
MySQL on localhost (3.22.32) up 3+23:14:20 [23:54:52]
Queries Total: 617 Avg/Sec: 0.00 Now/Sec: 0.05 Slow: 0
Threads Total: 1 Active: 1 Cached: 0
Key Efficiency: 88.38% Bytes in: 0 Bytes out: 0
The first line identified the hostname of the server (localhost) and the version of MySQL it is running. The right had side shows the uptime of the MySQL server process in days+hours:minutes:seconds format (much like FreeBSD’s top) as well as the current time.
The second line displays the total number of queries the server has processed, the average number of queries per second, the real-time number of queries per second, and the number of slow queries.
The third line deals with threads. Versions of MySQL before 3.23.x didn’t give out this information, so you’ll see all zeros.
And the fourth line displays key buffer efficiency (how often keys are read from the buffer rather than disk) and the number of bytes that MySQL has sent and received.
You can toggle the header by hitting h when running mytop.
The second part of the display lists as many threads as can fit on screen. By default they are sorted according to their idle time (least idle first). The display looks like:
Id User Host Dbase Time Cmd Query or State
— —- —- —– —- — ————–
61 jzawodn localhost music 0 Query show processlist
As you can see, the thread id, username, host from which the user is connecting, database to which the user is connected, number of seconds of idle time, the command the thread is executing, and the query info are all displayed.
Often times the query info is what you are really interested in, so it is good to run mytop in an xterm that is wider than the normal 80 columns if possible.
The thread display color-codes the threads if you have installed color support. The current color scheme only works well in a window with a dark (like black) background. The colors are selected according to the Command column of the display:
Query – Yellow
Sleep – White
Connect – Green
Those are purely arbitrary and will be customizable in a future release. If they annoy you just start mytop with the -nocolor flag or adjust your config file appropriately.
mytop handles long and short command-line arguments. Not all options have both long and short formats, however. The long arguments can start with one or two dashes `-‘ or `–‘. They are shown here with just one.
-u or -user username
Username to use when logging in to the MySQL server. Default: “root”.
-p or -pass or -password password
Password to use when logging in to the MySQL server. Default: none.
-h or -host hostname[: port]
Hostname of the MySQL server. The hostname may be followed by an option port number. Note that the port is specified separate from the host when using a config file. Default: “localhost”.
-port or -P port
If you’re running MySQL on a non-standard port, use this to specify the port number. Default: 3306.
-s or -delay seconds
How long between display refreshes. Default: 5
-d or -db or -database database
Use if you’d like mytop to connect to a specific database by default. Default: “test”.
-b or -batch or -batchmode
In batch mode, mytop runs only once, does not clear the screen, and places no limit on the number of lines it will print. This is suitable for running periodically (perhaps from cron) to capture the information into a file for later viewing. You might use batch mode in a CGI script to occasionally display your MySQL server status on the web.
-S or -socket /path/to/socket
If you’re running mytop on the same host as MySQL, you may wish to have it use the MySQL socket directly rather than a standard TCP/IP connection. If you do,just specify one.
Note that specifying a socket will make mytop ignore any host and/or port that you might have specified. If the socket does not exist (or the file specified is not a socket), this option will be ignored and mytop will use the hostname and port number instead.
-header or -noheader
Sepcify if you want the header to display or not. You can toggle this with the h key while mytop is running.
-color or -nocolor
Specify if you want a color display. This has no effect if you don’t have color support available.
Default: If you have color support, mytop will try color unless you tell it not to.
-i or -idle or -noidle
Specify if you want idle (sleeping) threads to appear in the list. If sleeping threads are omitted, the default sorting order is reversed so that the longest running queries appear at the top of the list.
Command-line arguments will always take precedence over config file options. That happens because the config file is read BEFORE the command-line arguments are applied.