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MYTOP(1) User Contributed Perl Documentation MYTOP(1)
NAME
mytop - display MySQL server performance info like `top'
SYNOPSIS
mytop [options]
AVAILABILITY
The latest version of mytop is available from
http://jeremy.zawodny.com/mysql/mytop/ it might also be on CPAN as
well.
REQUIREMENTS
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 GLOBAL 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.
Optional Color Support
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. :-)
Optional Hi-Res Timing
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.
Platforms
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.
DESCRIPTION
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.
The Basics
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 GLOBAL STATUS commands and attempt to summarize
the information from them in a useful format.
The Display
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 (4.0.13-log) up 1+11:13:00
[23:29:11]
Queries: 19.3M qps: 160 Slow: 1.0 Se/In/Up/De(%):
00/80/03/17
qps now: 219 Slow qps: 0.0 Threads: 1 ( 1/ 16)
00/74/00/25
Key Efficiency: 99.3% Bps in/out: 30.5k/162.8 Now in/out: 32.7k/
3.3k
The first line identifies 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 number of slow
queries, and the percentage of Select, Insert, Update, and Delete
queries.
The third real-time values. First is the number of queries per second,
then the number of slow queries, followed by query precentages (like on
the previous line).
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, both over all and in the last cycle.
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.
Arguments
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.
Default: unset.
-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.
Default: none.
-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.
Default: header.
-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.
Default: idle.
-prompt or -noprompt
Specify if you want to be prompted to type in your database
password. This provides a little bit more security since it not
only prevents the password from viewable in a process list, but
also doesn't require the password to be stored in plain text in
your ~/.mytop config file. You will only be prompted if a password
has not been specified in your config file or through another
command line option.
Default: noprompt.
-resolve
If you have skip-resolve set on MySQL (to keep it from doing a
reverse DNS lookup on each inbound connection), mytop can replace
IP addresses with hostnames but toggling this option.
Default: noresolve
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.
Config File
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.
Shortcut Keys
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.
? Display help.
c Show "command counters" based on the Com_* values in SHOW GLOBAL
STATUS. This is a new feature. Feedback welcome.
d Show only threads connected to a particular database.
f Given a thread id, display the entire query that thread was (and
still may be) running.
F Disable all filtering (host, user, and db).
h Only show queries from a particular host.
H Toggle the header display. You can also specify either "header=0"
or "header=1" in your config file to set the default behavior.
i Toggle the display of idle (sleeping) threads. If sleeping threads
are filtered, the default sorting order is reversed so that the
longest running queries appear at the top of the list.
I Switch to InnoDB Status mode. The output of "SHOW INNODB STATUS"
will be displayed every cycle. In a future version, this may
actually summarize that data rather than producing raw output.
k Kill a thread.
m Toggle modes. Currently this switches from `top' mode to `qps'
(Queries Per Second Mode). In this mode, mytop will write out one
integer per second. The number written reflects the number of
queries executed by the server in the previous one second interval.
More modes may be added in the future.
o Reverse the default sort order.
p Pause display.
q Quit mytop
r Reset the server's status counters via a FLUSH STATUS command.
s Change the sleep time (number of seconds between display
refreshes).
u Show only threads owned by a giver user.
The s key has a command-line counterpart: -s.
The h key has two command-line counterparts: -header and -noheader.
BUGS
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.
AUTHOR
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.
DISCLAIMER
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.
RECRUITING
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. :-(
SEE ALSO
Please check the MySQL manual if you're not sure where some of the
output of mytop is coming from.
COPYRIGHT
Copyright (C) 2000-2001, Jeremy D. Zawodny.
CREDITS
Fix a bug. Add a feature. See your name here!
Many thanks go to these fine folks:
Sami Ahlroos (sami@avis-net.de)
Suggested the idle/noidle stuff.
Jan Willamowius (jan@janhh.shnet.org)
Mirnor bug report. Documentation fixes.
Alex Osipov (alex@acky.net)
Long command-line options, Unix socket support.
Stephane Enten (tuf@grolier.fr)
Suggested batch mode.
Richard Ellerbrock (richarde@eskom.co.za)
Bug reports and usability suggestions.
William R. Mattil (wrm@newton.irngtx.tel.gte.com)
Bug report about empty passwords not working.
Benjamin Pflugmann (philemon@spin.de)
Suggested -P command-line flag as well as other changes.
Justin Mecham <justin@aspect.net>
Suggested setting $0 to `mytop'.
Thorsten Kunz <thorsten.kunz@de.tiscali.com>
Provided a fix for cases when we try remove the domain name from
the display even if it is actually an IP address.
Sasha Pachev <sasha@mysql.com>
Provided the idea of real-time queries per second in the main
display.
Paul DuBois <paul@snake.net>
Pointed out some option-handling bugs.
Mike Wexler <mwexler@tias.com>
Suggested that we don't mangle (normalize) whitespace in query info
by default.
Mark Zweifel <markez@yahoo-inc.com>
Make the --idle command-line argument negatable.
Axel Schwenke <schwenke@jobpilot.de>
Noticed the inccorect formula for query cache hit percentages in
version 1.2.
Steven Roussey <sroussey@network54.com>
Supplied a patch to help filter binary junk in queries so that
terminals don't freak out.
jon r. luini <falcon@chime.com>
Supplied a patch that formed the basis for "-prompt" support. Sean
Leach <sleach@wiggum.com> submitted a similar patch.
Yogish Baliga <baliga@yahoo-inc.com>
Supplied a patch that formed the basis for "-resolve" support.
Per Andreas Buer <perbu@linpro.no>
Supplied an excellent patch to tidy up the top display. This
includes showing most values in short form, such as 10k rather than
10000.
See the Changes file on the mytop distribution page for more details on
what has changed.
LICENSE
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
perl v5.20.2 2015-08-30 MYTOP(1)