mytop - display MySQL server performance info like `top'
mytop [options]
The latest version of mytop is available from http://jeremy.zawodny.com/mysql/mytop/ it might also be on CPAN as well.
In order for mytop to function properly, you must have the following:
* Perl 5.005 or newer * Getopt::Long * DBI and DBD::mysql * Term::ReadKey from CPAN
Most systems are likely to have all of those installed--except for Term::ReadKey. You will need to pick that up from the CPAN. You can pick up Term::ReadKey here:
http://search.cpan.org/search?dist=TermReadKey
And you obviously need access to a MySQL server (version 3.22.x or 3.23.x) with the necessary security to run the SHOW PROCESSLIST and SHOW STATUS commands.
If you are a Windows user, using ActiveState's Perl, you can use PPM (the Perl Package Manager) to install the MySQL and Term::ReadKey modules.
In additon, if you want a color mytop (recommended), install Term::ANSIColor from the CPAN:
http://search.cpan.org/search?dist=ANSIColor
Once you do, mytop will automatically use it. However, color is not yet working on Windows. Patches welcome. :-)
If you want mytop to provide more accurate real-time queries-per-second statistics, install the Time::HiRes module from CPAN. mytop will automatically notice that you have it and use it rather than the standard timing mechanism.
mytop is known to work on:
* Linux (2.2.x, 2.4.x) * FreeBSD (2.2, 3.x, 4.x) * Mac OS X * BSDI 4.x * Solaris 2.x * Windows NT 4.x (ActivePerl)
If you find that it works on another platform, please let me know. Given that it is all Perl code, I expect it to be rather portable to Unix and Unix-like systems. Heck, it might even work on Win32 systems.
Help is always welcome in improving this software. Feel free to contact the author (see AUTHOR below) with bug reports, fixes, suggestions, and comments. Additionally BUGS will provide a list of things this software is not able to do yet.
Having said that, here are the details on how it works and what you can do with it.
mytop was inspired by the system monitoring tool top. I routinely use top on Linux, FreeBSD, and Solaris. You are likely to notice features from each of them here.
mytop will connect to a MySQL server and periodically run the SHOW PROCESSLIST and SHOW STATUS commands and attempt to summarize the information from them in a useful format.
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.
Default: unset.
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.
Default: none.
Default: header.
Default: If you have color support, mytop will try color unless you tell it not to.
Default: idle.
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.
Instead of always using bulky command-line parameters, you can also
use a config file in your home directory (~/.mytop). If present,
mytop will read it automatically. It is read before any of your
command-line arguments are processed, so your command-line arguments
will override directives in the config file.
Here is a sample config file ~/.mytop which implements the defaults
described above.
user=root pass= host=localhost db=test delay=5 port=3306 socket= batchmode=0 header=1 color=1 idle=1
Using a config file will help to ensure that your database password
isn't visible to users on the command-line. Just make sure that the
permissions on ~/.mytop are such that others cannot read it (unless
you want them to, of course).
You may have white space on either side of the = in lines of the
config file.
The following keys perform various actions while mytop is running. Those which have not been implemented are listed as such. They are included to give the user idea of what is coming.
header=0 or
header=1 in your config file to set the default behavior.
More modes may be added in the future.
The s key has a command-line counterpart: -s.
The h key has two command-line counterparts: -header and -noheader.
This is more of a BUGS + WishList.
Some performance information is not available when talking to a version 3.22.x MySQL server. Additional information (about threads mostly) was added to the output of SHOW STATUS in MySQL 3.23.x and mytop makes use of it. If the information is not available, you will simply see zeros where the real numbers should be.
Simply running this program will increase your overall counters (such as the number of queries run). But you may or may not view that as a bug.
mytop consumes too much CPU time when running (verified on older
versions of Linux and FreeBSD). It's likely a problem related to
Term::ReadKey. I haven't had time to investigate yet, so mytop now
automatically lowers its priority when you run it. You may also think
about running mytop on another workstation instead of your database
server. However, mytop on Solaris does not have this problem.
Newer versions of Linux and FreeBSD seem to have fixed this.
You can't specify the maximum number of threads to list. If you have many threads and a tall xterm, mytop will always try to display as many as it can fit.
The size of most of the columns in the display has a small maximum width. If you have fairly long database/user/host names the display may appear odd. I have no good idea as to how best to deal with that yet. Suggestions are welcome.
It'd be nice if you could just add mytop configuration directives
in your my.cnf file instead of having a separate config file.
You should be able to specify the columns you'd like to see in the display and the order in which they appear. If you only have one username that connects to your database, it's probably not worth having the User column appear, for example.
mytop was developed and is maintained by Jeremy D. Zawodny (Jeremy@Zawodny.com)
If you wish to e-mail me regarding this software, PLEASE subscribe to the mytop mailing list. See the mytop homepage for details.
While I use this software in my job at Yahoo!, I am solely responsible for it. Yahoo! does not necessarily support this software in any way. It is merely a personal idea which happened to be very useful in my job.
If you hack Perl and grok MySQL, come work at Yahoo! Contact me for details. Or just send me your resume. Er, unless we just had layoffs, in which case we're not hiring. :-(
Please check the MySQL manual if you're not sure where some of the output of mytop is coming from.
Copyright (C) 2000-2001, Jeremy D. Zawodny.
Fix a bug. Add a feature. See your name here!
Many thanks go to these fine folks:
See the Changes file on the mytop distribution page for more details on what has changed.
mytop is licensed under the GNU General Public License version 2. For the full license information, please visit http://www.gnu.org/copyleft/gpl.html