NAME¶
innotop - MySQL and InnoDB transaction/status monitor.
SYNOPSIS¶
To monitor servers normally:
innotop
To monitor InnoDB status information from a file:
innotop /var/log/mysql/mysqld.err
To run innotop non-interactively in a pipe-and-filter configuration:
innotop --count 5 -d 1 -n
To monitor a database on another system using a particular username and
password:
innotop -u <username> -p <password> -h <hostname>
DESCRIPTION¶
innotop monitors MySQL servers. Each of its modes shows you a different aspect
of what's happening in the server. For example, there's a mode for monitoring
replication, one for queries, and one for transactions. innotop refreshes its
data periodically, so you see an updating view.
innotop has lots of features for power users, but you can start and run it with
virtually no configuration. If you're just getting started, see
"QUICK-START". Press '?' at any time while running innotop for
context-sensitive help.
QUICK-START¶
To start innotop, open a terminal or command prompt. If you have installed
innotop on your system, you should be able to just type "innotop"
and press Enter; otherwise, you will need to change to innotop's directory and
type "perl innotop".
With no options specified, innotop will attempt to connect to a MySQL server on
localhost using mysql_read_default_group=client for other connection
parameters. If you need to specify a different username and password, use the
-u and -p options, respectively. To monitor a MySQL database on another host,
use the -h option.
After you've connected, innotop should show you something like the following:
[RO] Query List (? for help) localhost, 01:11:19, 449.44 QPS, 14/7/163 con/run
CXN When Load QPS Slow QCacheHit KCacheHit BpsIn BpsOut
localhost Total 0.00 1.07k 697 0.00% 98.17% 476.83k 242.83k
CXN Cmd ID User Host DB Time Query
localhost Query 766446598 test 10.0.0.1 foo 00:02 INSERT INTO table (
(This sample is truncated at the right so it will fit on a terminal when running
'man innotop')
If your server is busy, you'll see more output. Notice the first line on the
screen, which tells you that readonly is set to true ([RO]), what mode you're
in and what server you're connected to. You can change to other modes with
keystrokes; press 'T' to switch to a list of InnoDB transactions, for example.
Press the '?' key to see what keys are active in the current mode. You can press
any of these keys and innotop will either take the requested action or prompt
you for more input. If your system has Term::ReadLine support, you can use TAB
and other keys to auto-complete and edit input.
To quit innotop, press the 'q' key.
OPTIONS¶
innotop is mostly configured via its configuration file, but some of the
configuration options can come from the command line. You can also specify a
file to monitor for InnoDB status output; see "MONITORING A FILE"
for more details.
You can negate some options by prefixing the option name with --no. For example,
--noinc (or --no-inc) negates "--inc".
- --color
- Enable or disable terminal coloring. Corresponds to the "color"
config file setting.
- --config
- Specifies a configuration file to read. This option is non-sticky, that is
to say it does not persist to the configuration file itself.
- --count
- Refresh only the specified number of times (ticks) before exiting. Each
refresh is a pause for "interval" seconds, followed by
requesting data from MySQL connections and printing it to the
terminal.
- --delay
- Specifies the amount of time to pause between ticks (refreshes).
Corresponds to the configuration option "interval".
- --help
- Print a summary of command-line usage and exit.
- --host
- Host to connect to.
- --inc
- Specifies whether innotop should display absolute numbers or relative
numbers (offsets from their previous values). Corresponds to the
configuration option "status_inc".
- --mode
- Specifies the mode in which innotop should start. Corresponds to the
configuration option "mode".
- --nonint
- Enable non-interactive operation. See "NON-INTERACTIVE
OPERATION" for more.
- --password
- Password to use for connection.
- --port
- Port to use for connection.
- --skipcentral
- Don't read the central configuration file.
- --user
- User to use for connection.
- --version
- Output version information and exit.
- --write
- Sets the configuration option "readonly" to 0, making innotop
write the running configuration to ~/.innotop/innotop.conf on exit, if no
configuration file was loaded at start-up.
HOTKEYS¶
innotop is interactive, and you control it with key-presses.
- •
- Uppercase keys switch between modes.
- •
- Lowercase keys initiate some action within the current mode.
- •
- Other keys do something special like change configuration or show the
innotop license.
Press '?' at any time to see the currently active keys and what they do.
MODES¶
Each of innotop's modes retrieves and displays a particular type of data from
the servers you're monitoring. You switch between modes with uppercase keys.
The following is a brief description of each mode, in alphabetical order. To
switch to the mode, press the key listed in front of its heading in the
following list:
- B: InnoDB Buffers
- This mode displays information about the InnoDB buffer pool, page
statistics, insert buffer, and adaptive hash index. The data comes from
SHOW INNODB STATUS.
This mode contains the "buffer_pool", "page_statistics",
"insert_buffers", and "adaptive_hash_index" tables by
default.
- C: Command Summary
- This mode is similar to mytop's Command Summary mode. It shows the
"cmd_summary" table, which looks something like the following:
Command Summary (? for help) localhost, 25+07:16:43, 2.45 QPS, 3 thd, 5.0.40
_____________________ Command Summary _____________________
Name Value Pct Last Incr Pct
Select_scan 3244858 69.89% 2 100.00%
Select_range 1354177 29.17% 0 0.00%
Select_full_join 39479 0.85% 0 0.00%
Select_full_range_join 4097 0.09% 0 0.00%
Select_range_check 0 0.00% 0 0.00%
The command summary table is built by extracting variables from
"STATUS_VARIABLES". The variables must be numeric and must match
the prefix given by the "cmd_filter" configuration variable. The
variables are then sorted by value descending and compared to the last
variable, as shown above. The percentage columns are percentage of the
total of all variables in the table, so you can see the relative weight of
the variables.
The example shows what you see if the prefix is "Select_". The
default prefix is "Com_". You can choose a prefix with the 's'
key.
It's rather like running SHOW VARIABLES LIKE "prefix%" with memory
and nice formatting.
Values are aggregated across all servers. The Pct columns are not correctly
aggregated across multiple servers. This is a known limitation of the
grouping algorithm that may be fixed in the future.
- D: InnoDB Deadlocks
- This mode shows the transactions involved in the last InnoDB deadlock. A
second table shows the locks each transaction held and waited for. A
deadlock is caused by a cycle in the waits-for graph, so there should be
two locks held and one waited for unless the deadlock information is
truncated.
InnoDB puts deadlock information before some other information in the SHOW
INNODB STATUS output. If there are a lot of locks, the deadlock
information can grow very large, and there is a limit on the size of the
SHOW INNODB STATUS output. A large deadlock can fill the entire output, or
even be truncated, and prevent you from seeing other information at all.
If you are running innotop in another mode, for example T mode, and
suddenly you don't see anything, you might want to check and see if a
deadlock has wiped out the data you need.
If it has, you can create a small deadlock to replace the large one. Use the
'w' key to 'wipe' the large deadlock with a small one. This will not work
unless you have defined a deadlock table for the connection (see
"SERVER CONNECTIONS").
You can also configure innotop to automatically detect when a large deadlock
needs to be replaced with a small one (see "auto_wipe_dl").
This mode displays the "deadlock_transactions" and
"deadlock_locks" tables by default.
- F: InnoDB Foreign Key Errors
- This mode shows the last InnoDB foreign key error information, such as the
table where it happened, when and who and what query caused it, and so on.
InnoDB has a huge variety of foreign key error messages, and many of them
are just hard to parse. innotop doesn't always do the best job here, but
there's so much code devoted to parsing this messy, unparseable output
that innotop is likely never to be perfect in this regard. If innotop
doesn't show you what you need to see, just look at the status text
directly.
This mode displays the "fk_error" table by default.
- I: InnoDB I/O Info
- This mode shows InnoDB's I/O statistics, including the I/O threads,
pending I/O, file I/O miscellaneous, and log statistics. It displays the
"io_threads", "pending_io", "file_io_misc",
and "log_statistics" tables by default.
- L: Locks
- This mode shows information about current locks. At the moment only InnoDB
locks are supported, and by default you'll only see locks for which
transactions are waiting. This information comes from the TRANSACTIONS
section of the InnoDB status text. If you have a very busy server, you may
have frequent lock waits; it helps to be able to see which tables and
indexes are the "hot spot" for locks. If your server is running
pretty well, this mode should show nothing.
You can configure MySQL and innotop to monitor not only locks for which a
transaction is waiting, but those currently held, too. You can do this
with the InnoDB Lock Monitor
(<http://dev.mysql.com/doc/en/innodb-monitor.html>). It's not
documented in the MySQL manual, but creating the lock monitor with the
following statement also affects the output of SHOW INNODB STATUS, which
innotop uses:
CREATE TABLE innodb_lock_monitor(a int) ENGINE=INNODB;
This causes InnoDB to print its output to the MySQL file every 16 seconds or
so, as stated in the manual, but it also makes the normal SHOW INNODB
STATUS output include lock information, which innotop can parse and
display (that's the undocumented feature).
This means you can do what may have seemed impossible: to a limited extent
(InnoDB truncates some information in the output), you can see which
transaction holds the locks something else is waiting for. You can also
enable and disable the InnoDB Lock Monitor with the key mappings in this
mode.
This mode displays the "innodb_locks" table by default. Here's a
sample of the screen when one connection is waiting for locks another
connection holds:
_________________________________ InnoDB Locks __________________________
CXN ID Type Waiting Wait Active Mode DB Table Index
localhost 12 RECORD 1 00:10 00:10 X test t1 PRIMARY
localhost 12 TABLE 0 00:10 00:10 IX test t1
localhost 12 RECORD 1 00:10 00:10 X test t1 PRIMARY
localhost 11 TABLE 0 00:00 00:25 IX test t1
localhost 11 RECORD 0 00:00 00:25 X test t1 PRIMARY
You can see the first connection, ID 12, is waiting for a lock on the
PRIMARY key on test.t1, and has been waiting for 10 seconds. The second
connection isn't waiting, because the Waiting column is 0, but it holds
locks on the same index. That tells you connection 11 is blocking
connection 12.
- M: Master/Slave Replication Status
- This mode shows the output of SHOW SLAVE STATUS and SHOW MASTER STATUS in
three tables. The first two divide the slave's status into SQL and I/O
thread status, and the last shows master status. Filters are applied to
eliminate non-slave servers from the slave tables, and non-master servers
from the master table.
This mode displays the "slave_sql_status",
"slave_io_status", and "master_status" tables by
default.
- O: Open Tables
- This section comes from MySQL's SHOW OPEN TABLES command. By default it is
filtered to show tables which are in use by one or more queries, so you
can get a quick look at which tables are 'hot'. You can use this to guess
which tables might be locked implicitly.
This mode displays the "open_tables" mode by default.
- Q: Query List
- This mode displays the output from SHOW FULL PROCESSLIST, much like
mytop's query list mode. This mode does not show
InnoDB-related information. This is probably one of the most useful modes
for general usage.
There is an informative header that shows general status information about
your server. You can toggle it on and off with the 'h' key. By default,
innotop hides inactive processes and its own process. You can toggle these
on and off with the 'i' and 'a' keys.
You can EXPLAIN a query from this mode with the 'e' key. This displays the
query's full text, the results of EXPLAIN, and in newer MySQL versions,
even the optimized query resulting from EXPLAIN EXTENDED. innotop also
tries to rewrite certain queries to make them EXPLAIN-able. For example,
INSERT/SELECT statements are rewritable.
This mode displays the "q_header" and "processlist"
tables by default.
- R: InnoDB Row Operations and Semaphores
- This mode shows InnoDB row operations, row operation miscellaneous,
semaphores, and information from the wait array. It displays the
"row_operations", "row_operation_misc",
"semaphores", and "wait_array" tables by default.
- S: Variables & Status
- This mode calculates statistics, such as queries per second, and prints
them out in several different styles. You can show absolute values, or
incremental values between ticks.
You can switch between the views by pressing a key. The 's' key prints a
single line each time the screen updates, in the style of vmstat.
The 'g' key changes the view to a graph of the same numbers, sort of like
tload. The 'v' key changes the view to a pivoted table of variable
names on the left, with successive updates scrolling across the screen
from left to right. You can choose how many updates to put on the screen
with the "num_status_sets" configuration variable.
Headers may be abbreviated to fit on the screen in interactive operation.
You choose which variables to display with the 'c' key, which selects from
predefined sets, or lets you create your own sets. You can edit the
current set with the 'e' key.
This mode doesn't really display any tables like other modes. Instead, it
uses a table definition to extract and format the data, but it then
transforms the result in special ways before outputting it. It uses the
"var_status" table definition for this.
- T: InnoDB Transactions
- This mode shows transactions from the InnoDB monitor's output, in
top-like format. This mode is the reason I wrote innotop.
You can kill queries or processes with the 'k' and 'x' keys, and EXPLAIN a
query with the 'e' or 'f' keys. InnoDB doesn't print the full query in
transactions, so explaining may not work right if the query is truncated.
The informational header can be toggled on and off with the 'h' key. By
default, innotop hides inactive transactions and its own transaction. You
can toggle this on and off with the 'i' and 'a' keys.
This mode displays the "t_header" and
"innodb_transactions" tables by default.
INNOTOP STATUS¶
The first line innotop displays is a "status bar" of sorts. What it
contains depends on the mode you're in, and what servers you're monitoring.
The first few words are always [RO] (if readonly is set to 1), the innotop
mode, such as "InnoDB Txns" for T mode, followed by a reminder to
press '?' for help at any time.
ONE SERVER¶
The simplest case is when you're monitoring a single server. In this case, the
name of the connection is next on the status line. This is the name you gave
when you created the connection -- most likely the MySQL server's hostname.
This is followed by the server's uptime.
If you're in an InnoDB mode, such as T or B, the next word is "InnoDB"
followed by some information about the SHOW INNODB STATUS output used to
render the screen. The first word is the number of seconds since the last SHOW
INNODB STATUS, which InnoDB uses to calculate some per-second statistics. The
next is a smiley face indicating whether the InnoDB output is truncated. If
the smiley face is a :-), all is well; there is no truncation. A :^| means the
transaction list is so long, InnoDB has only printed out some of the
transactions. Finally, a frown :-( means the output is incomplete, which is
probably due to a deadlock printing too much lock information (see "D:
InnoDB Deadlocks").
The next two words indicate the server's queries per second (QPS) and how many
threads (connections) exist. Finally, the server's version number is the last
thing on the line.
MULTIPLE SERVERS¶
If you are monitoring multiple servers (see "SERVER CONNECTIONS"), the
status line does not show any details about individual servers. Instead, it
shows the names of the connections that are active. Again, these are
connection names you specified, which are likely to be the server's hostname.
A connection that has an error is prefixed with an exclamation point.
If you are monitoring a group of servers (see "SERVER GROUPS"), the
status line shows the name of the group. If any connection in the group has an
error, the group's name is followed by the fraction of the connections that
don't have errors.
See "ERROR HANDLING" for more details about innotop's error handling.
MONITORING A FILE¶
If you give a filename on the command line, innotop will not connect to ANY
servers at all. It will watch the specified file for InnoDB status output and
use that as its data source. It will always show a single connection called
'file'. And since it can't connect to a server, it can't determine how long
the server it's monitoring has been up; so it calculates the server's uptime
as time since innotop started running.
SERVER ADMINISTRATION¶
While innotop is primarily a monitor that lets you watch and analyze your
servers, it can also send commands to servers. The most frequently useful
commands are killing queries and stopping or starting slaves.
You can kill a connection, or in newer versions of MySQL kill a query but not a
connection, from "Q: Query List" and "T: InnoDB
Transactions" modes. Press 'k' to issue a KILL command, or 'x' to issue a
KILL QUERY command. innotop will prompt you for the server and/or connection
ID to kill (innotop does not prompt you if there is only one possible choice
for any input). innotop pre-selects the longest-running query, or the oldest
connection. Confirm the command with 'y'.
In "Slave Replication Status"" in "M: Master mode, you can
start and stop slaves with the 'a' and 'o' keys, respectively. You can send
these commands to many slaves at once. innotop fills in a default command of
START SLAVE or STOP SLAVE for you, but you can actually edit the command and
send anything you wish, such as SET GLOBAL SQL_SLAVE_SKIP_COUNTER=1 to make
the slave skip one binlog event when it starts.
You can also ask innotop to calculate the earliest binlog in use by any slave
and issue a PURGE MASTER LOGS on the master. Use the 'b' key for this. innotop
will prompt you for a master to run the command on, then prompt you for the
connection names of that master's slaves (there is no way for innotop to
determine this reliably itself). innotop will find the minimum binlog in use
by these slave connections and suggest it as the argument to PURGE MASTER
LOGS.
SERVER CONNECTIONS¶
When you create a server connection using '@', innotop asks you for a series of
inputs, as follows:
- DSN
- A DSN is a Data Source Name, which is the initial argument passed to the
DBI module for connecting to a server. It is usually of the form
DBI:mysql:;mysql_read_default_group=mysql;host=HOSTNAME
Since this DSN is passed to the DBD::mysql driver, you should read the
driver's documentation at
"/search.cpan.org/dist/DBD-mysql/lib/DBD/mysql.pm"" in
"http: for the exact details on all the options you can pass the
driver in the DSN. You can read more about DBI at
<http://dbi.perl.org/docs/>, and especially at
<http://search.cpan.org/~timb/DBI/DBI.pm>.
The mysql_read_default_group=mysql option lets the DBD driver read your
MySQL options files, such as ~/.my.cnf on UNIX-ish systems. You can use
this to avoid specifying a username or password for the connection.
- InnoDB Deadlock Table
- This optional item tells innotop a table name it can use to deliberately
create a small deadlock (see "D: InnoDB Deadlocks"). If you
specify this option, you just need to be sure the table doesn't exist, and
that innotop can create and drop the table with the InnoDB storage engine.
You can safely omit or just accept the default if you don't intend to use
this.
- Username
- innotop will ask you if you want to specify a username. If you say 'y', it
will then prompt you for a user name. If you have a MySQL option file that
specifies your username, you don't have to specify a username.
The username defaults to your login name on the system you're running
innotop on.
- Password
- innotop will ask you if you want to specify a password. Like the username,
the password is optional, but there's an additional prompt that asks if
you want to save the password in the innotop configuration file. If you
don't save it in the configuration file, innotop will prompt you for a
password each time it starts. Passwords in the innotop configuration file
are saved in plain text, not encrypted in any way.
Once you finish answering these questions, you should be connected to a server.
But innotop isn't limited to monitoring a single server; you can define many
server connections and switch between them by pressing the '@' key. See
"SWITCHING BETWEEN CONNECTIONS".
SERVER GROUPS¶
If you have multiple MySQL instances, you can put them into named groups, such
as 'all', 'masters', and 'slaves', which innotop can monitor all together.
You can choose which group to monitor with the '#' key, and you can press the
TAB key to switch to the next group. If you're not currently monitoring a
group, pressing TAB selects the first group.
To create a group, press the '#' key and type the name of your new group, then
type the names of the connections you want the group to contain.
SWITCHING BETWEEN CONNECTIONS¶
innotop lets you quickly switch which servers you're monitoring. The most basic
way is by pressing the '@' key and typing the name(s) of the connection(s) you
want to use. This setting is per-mode, so you can monitor different
connections in each mode, and innotop remembers which connections you choose.
You can quickly switch to the 'next' connection in alphabetical order with the
'n' key. If you're monitoring a server group (see "SERVER GROUPS")
this will switch to the first connection.
You can also type many connection names, and innotop will fetch and display data
from them all. Just separate the connection names with spaces, for example
"server1 server2." Again, if you type the name of a connection that
doesn't exist, innotop will prompt you for connection information and create
the connection.
Another way to monitor multiple connections at once is with server groups. You
can use the TAB key to switch to the 'next' group in alphabetical order, or if
you're not monitoring any groups, TAB will switch to the first group.
innotop does not fetch data in parallel from connections, so if you are
monitoring a large group or many connections, you may notice increased delay
between ticks.
When you monitor more than one connection, innotop's status bar changes. See
"INNOTOP STATUS".
ERROR HANDLING¶
Error handling is not that important when monitoring a single connection, but is
crucial when you have many active connections. A crashed server or lost
connection should not crash innotop. As a result, innotop will continue to run
even when there is an error; it just won't display any information from the
connection that had an error. Because of this, innotop's behavior might
confuse you. It's a feature, not a bug!
innotop does not continue to query connections that have errors, because they
may slow innotop and make it hard to use, especially if the error is a problem
connecting and causes a long time-out. Instead, innotop retries the connection
occasionally to see if the error still exists. If so, it will wait until some
point in the future. The wait time increases in ticks as the Fibonacci series,
so it tries less frequently as time passes.
Since errors might only happen in certain modes because of the SQL commands
issued in those modes, innotop keeps track of which mode caused the error. If
you switch to a different mode, innotop will retry the connection instead of
waiting.
By default innotop will display the problem in red text at the bottom of the
first table on the screen. You can disable this behavior with the
"show_cxn_errors_in_tbl" configuration option, which is enabled by
default. If the "debug" option is enabled, innotop will display the
error at the bottom of every table, not just the first. And if
"show_cxn_errors" is enabled, innotop will print the error text to
STDOUT as well. Error messages might only display in the mode that caused the
error, depending on the mode and whether innotop is avoiding querying that
connection.
NON-INTERACTIVE OPERATION¶
You can run innotop in non-interactive mode, in which case it is entirely
controlled from the configuration file and command-line options. To start
innotop in non-interactive mode, give the L"<--nonint">
command-line option. This changes innotop's behavior in the following ways:
- •
- Certain Perl modules are not loaded. Term::Readline is not loaded, since
innotop doesn't prompt interactively. Term::ANSIColor and
Win32::Console::ANSI modules are not loaded. Term::ReadKey is still used,
since innotop may have to prompt for connection passwords when starting
up.
- •
- innotop does not clear the screen after each tick.
- •
- innotop does not persist any changes to the configuration file.
- •
- If "--count" is given and innotop is in incremental mode (see
"status_inc" and "--inc"), innotop actually refreshes
one more time than specified so it can print incremental statistics. This
suppresses output during the first tick, so innotop may appear to
hang.
- •
- innotop only displays the first table in each mode. This is so the output
can be easily processed with other command-line utilities such as awk and
sed. To change which tables display in each mode, see "TABLES".
Since "Q: Query List" mode is so important, innotop
automatically disables the "q_header" table. This ensures you'll
see the "processlist" table, even if you have innotop configured
to show the q_header table during interactive operation. Similarly, in
"T: InnoDB Transactions" mode, the "t_header" table is
suppressed so you see only the "innodb_transactions" table.
- •
- All output is tab-separated instead of being column-aligned with
whitespace, and innotop prints the full contents of each table instead of
only printing one screenful at a time.
- •
- innotop only prints column headers once instead of every tick (see
"hide_hdr"). innotop does not print table captions (see
"display_table_captions"). innotop ensures there are no empty
lines in the output.
- •
- innotop does not honor the "shorten" transformation, which
normally shortens some numbers to human-readable formats.
- •
- innotop does not print a status line (see "INNOTOP
STATUS").
CONFIGURING¶
Nearly everything about innotop is configurable. Most things are possible to
change with built-in commands, but you can also edit the configuration file.
While running innotop, press the '$' key to bring up the configuration editing
dialog. Press another key to select the type of data you want to edit:
- S: Statement Sleep Times
- Edits SQL statement sleep delays, which make innotop pause for the
specified amount of time after executing a statement. See "SQL
STATEMENTS" for a definition of each statement and what it does. By
default innotop does not delay after any statements.
This feature is included so you can customize the side-effects caused by
monitoring your server. You may not see any effects, but some innotop
users have noticed that certain MySQL versions under very high load with
InnoDB enabled take longer than usual to execute SHOW GLOBAL STATUS. If
innotop calls SHOW FULL PROCESSLIST immediately afterward, the processlist
contains more queries than the machine actually averages at any given
moment. Configuring innotop to pause briefly after calling SHOW GLOBAL
STATUS alleviates this effect.
Sleep times are stored in the "stmt_sleep_times" section of the
configuration file. Fractional-second sleeps are supported, subject to
your hardware's limitations.
- c: Edit Columns
- Starts the table editor on one of the displayed tables. See "TABLE
EDITOR". An alternative way to start the table editor without
entering the configuration dialog is with the '^' key.
- g: General Configuration
- Starts the configuration editor to edit global and mode-specific
configuration variables (see "MODES"). innotop prompts you to
choose a variable from among the global and mode-specific ones depending
on the current mode.
- k: Row-Coloring Rules
- Starts the row-coloring rules editor on one of the displayed table(s). See
"COLORS" for details.
- p: Manage Plugins
- Starts the plugin configuration editor. See "PLUGINS" for
details.
- s: Server Groups
- Lets you create and edit server groups. See "SERVER
GROUPS".
- t: Choose Displayed Tables
- Lets you choose which tables to display in this mode. See
"MODES" and "TABLES".
CONFIGURATION FILE¶
innotop's default configuration file locations are $HOME/.innotop and
/etc/innotop/innotop.conf, and they are looked for in that order. If the first
configuration file exists, the second will not be processed. Those can be
overridden with the "--config" command-line option. You can edit it
by hand safely, however innotop reads the configuration file when it starts,
and, if readonly is set to 0, writes it out again when it exits. Thus, if
readonly is set to 0, any changes you make by hand while innotop is running
will be lost.
innotop doesn't store its entire configuration in the configuration file. It has
a huge set of default configuration values that it holds only in memory, and
the configuration file only overrides these defaults. When you customize a
default setting, innotop notices, and then stores the customizations into the
file. This keeps the file size down, makes it easier to edit, and makes
upgrades easier.
A configuration file is read-only be default. You can override that with
"--write". See "readonly".
The configuration file is arranged into sections like an INI file. Each section
begins with [section-name] and ends with [/section-name]. Each section's
entries have a different syntax depending on the data they need to store. You
can put comments in the file; any line that begins with a # character is a
comment. innotop will not read the comments, so it won't write them back out
to the file when it exits. Comments in read-only configuration files are still
useful, though.
The first line in the file is innotop's version number. This lets innotop notice
when the file format is not backwards-compatible, and upgrade smoothly without
destroying your customized configuration.
The following list describes each section of the configuration file and the data
it contains:
- general
- The 'general' section contains global configuration variables and
variables that may be mode-specific, but don't belong in any other
section. The syntax is a simple key=value list. innotop writes a comment
above each value to help you edit the file by hand.
- S_func
- Controls S mode presentation (see "S: Variables & Status").
If g, values are graphed; if s, values are like vmstat; if p, values are
in a pivoted table.
- S_set
- Specifies which set of variables to display in "S: Variables &
Status" mode. See "VARIABLE SETS".
- auto_wipe_dl
- Instructs innotop to automatically wipe large deadlocks when it notices
them. When this happens you may notice a slight delay. At the next tick,
you will usually see the information that was being truncated by the large
deadlock.
- charset
- Specifies what kind of characters to allow through the
"no_ctrl_char" transformation. This keeps non-printable
characters from confusing a terminal when you monitor queries that contain
binary data, such as images.
The default is 'ascii', which considers anything outside normal ASCII to be
a control character. The other allowable values are 'unicode' and 'none'.
'none' considers every character a control character, which can be useful
for collapsing ALL text fields in queries.
- cmd_filter
- This is the prefix that filters variables in "C: Command
Summary" mode.
- color
- Whether terminal coloring is permitted.
- cxn_timeout
- On MySQL versions 4.0.3 and newer, this variable is used to set the
connection's timeout, so MySQL doesn't close the connection if it is not
used for a while. This might happen because a connection isn't monitored
in a particular mode, for example.
- debug
- This option enables more verbose errors and makes innotop more strict in
some places. It can help in debugging filters and other user-defined code.
It also makes innotop write a lot of information to "debugfile"
when there is a crash.
- debugfile
- A file to which innotop will write information when there is a crash. See
"FILES".
- display_table_captions
- innotop displays a table caption above most tables. This variable
suppresses or shows captions on all tables globally. Some tables are
configured with the hide_caption property, which overrides this.
- global
- Whether to show GLOBAL variables and status. innotop only tries to do this
on servers which support the GLOBAL option to SHOW VARIABLES and SHOW
STATUS. In some MySQL versions, you need certain privileges to do this; if
you don't have them, innotop will not be able to fetch any variable and
status data. This configuration variable lets you run innotop and fetch
what data you can even without the elevated privileges.
I can no longer find or reproduce the situation where GLOBAL wasn't allowed,
but I know there was one.
- graph_char
- Defines the character to use when drawing graphs in "S: Variables
& Status" mode.
- header_highlight
- Defines how to highlight column headers. This only works if
Term::ANSIColor is available. Valid values are 'bold' and
'underline'.
- hide_hdr
- Hides column headers globally.
- interval
- The interval at which innotop will refresh its data (ticks). The interval
is implemented as a sleep time between ticks, so the true interval will
vary depending on how long it takes innotop to fetch and render data.
This variable accepts fractions of a second.
- mode
- The mode in which innotop should start. Allowable arguments are the same
as the key presses that select a mode interactively. See
"MODES".
- num_digits
- How many digits to show in fractional numbers and percents. This
variable's range is between 0 and 9 and can be set directly from "S:
Variables & Status" mode with the '+' and '-' keys. It is used in
the "set_precision", "shorten", and
"percent" transformations.
- num_status_sets
- Controls how many sets of status variables to display in pivoted "S:
Variables & Status" mode. It also controls the number of old sets
of variables innotop keeps in its memory, so the larger this variable is,
the more memory innotop uses.
- plugin_dir
- Specifies where plugins can be found. By default, innotop stores plugins
in the 'plugins' subdirectory of your innotop configuration
directory.
- readonly
- Whether the configuration file is readonly. This cannot be set
interactively.
- show_cxn_errors
- Makes innotop print connection errors to STDOUT. See "ERROR
HANDLING".
- show_cxn_errors_in_tbl
- Makes innotop display connection errors as rows in the first table on
screen. See "ERROR HANDLING".
- show_percent
- Adds a '%' character after the value returned by the "percent"
transformation.
- show_statusbar
- Controls whether to show the status bar in the display. See "INNOTOP
STATUS".
- skip_innodb
- Disables fetching SHOW INNODB STATUS, in case your server(s) do not have
InnoDB enabled and you don't want innotop to try to fetch it. This can
also be useful when you don't have the SUPER privilege, required to run
SHOW INNODB STATUS.
- status_inc
- Whether to show absolute or incremental values for status variables.
Incremental values are calculated as an offset from the last value innotop
saw for that variable. This is a global setting, but will probably become
mode-specific at some point. Right now it is honored a bit inconsistently;
some modes don't pay attention to it.
- plugins
- This section holds a list of package names of active plugins. If the
plugin exists, innotop will activate it. See "PLUGINS" for more
information.
- filters
- This section holds user-defined filters (see "FILTERS"). Each
line is in the format filter_name=text='filter text' tbls='table list'.
The filter text is the text of the subroutine's code. The table list is a
list of tables to which the filter can apply. By default, user-defined
filters apply to the table for which they were created, but you can
manually override that by editing the definition in the configuration
file.
- active_filters
- This section stores which filters are active on each table. Each line is
in the format table_name=filter_list.
- tbl_meta
- This section stores user-defined or user-customized columns (see
"COLUMNS"). Each line is in the format col_name=properties,
where the properties are a name=quoted-value list.
- connections
- This section holds the server connections you have defined. Each line is
in the format name=properties, where the properties are a name=value list.
The properties are self-explanatory, and the only one that is treated
specially is 'pass' which is only present if 'savepass' is set. This
section of the configuration file will be skipped if any DSN, username, or
password command-line options are used. See "SERVER
CONNECTIONS".
- active_connections
- This section holds a list of which connections are active in each mode.
Each line is in the format mode_name=connection_list.
- server_groups
- This section holds server groups. Each line is in the format
name=connection_list. See "SERVER GROUPS".
- active_server_groups
- This section holds a list of which server group is active in each mode.
Each line is in the format mode_name=server_group.
- max_values_seen
- This section holds the maximum values seen for variables. This is used to
scale the graphs in "S: Variables & Status" mode. Each line
is in the format name=value.
- active_columns
- This section holds table column lists. Each line is in the format
tbl_name=column_list. See "COLUMNS".
- sort_cols
- This section holds the sort definition. Each line is in the format
tbl_name=column_list. If a column is prefixed with '-', that column sorts
descending. See "SORTING".
- visible_tables
- This section defines which tables are visible in each mode. Each line is
in the format mode_name=table_list. See "TABLES".
- varsets
- This section defines variable sets for use in "S: Status &
Variables" mode. Each line is in the format name=variable_list. See
"VARIABLE SETS".
- colors
- This section defines colorization rules. Each line is in the format
tbl_name=property_list. See "COLORS".
- stmt_sleep_times
- This section contains statement sleep times. Each line is in the format
statement_name=sleep_time. See "S: Statement Sleep Times".
- group_by
- This section contains column lists for table group_by expressions. Each
line is in the format tbl_name=column_list. See "GROUPING".
CUSTOMIZING¶
You can customize innotop a great deal. For example, you can:
- •
- Choose which tables to display, and in what order.
- •
- Choose which columns are in those tables, and create new columns.
- •
- Filter which rows display with built-in filters, user-defined filters, and
quick-filters.
- •
- Sort the rows to put important data first or group together related
rows.
- •
- Highlight rows with color.
- •
- Customize the alignment, width, and formatting of columns, and apply
transformations to columns to extract parts of their values or format the
values as you wish (for example, shortening large numbers to familiar
units).
- •
- Design your own expressions to extract and combine data as you need. This
gives you unlimited flexibility.
All these and more are explained in the following sections.
TABLES¶
A table is what you'd expect: a collection of columns. It also has some other
properties, such as a caption. Filters, sorting rules, and colorization rules
belong to tables and are covered in later sections.
Internally, table meta-data is defined in a data structure called %tbl_meta.
This hash holds all built-in table definitions, which contain a lot of default
instructions to innotop. The meta-data includes the caption, a list of columns
the user has customized, a list of columns, a list of visible columns, a list
of filters, color rules, a sort-column list, sort direction, and some
information about the table's data sources. Most of this is customizable via
the table editor (see "TABLE EDITOR").
You can choose which tables to show by pressing the '$' key. See
"MODES" and "TABLES".
The table life-cycle is as follows:
- •
- Each table begins with a data source, which is an array of hashes. See
below for details on data sources.
- •
- Each element of the data source becomes a row in the final table.
- •
- For each element in the data source, innotop extracts values from the
source and creates a row. This row is another hash, which later steps will
refer to as $set. The values innotop extracts are determined by the
table's columns. Each column has an extraction subroutine, compiled from
an expression (see "EXPRESSIONS"). The resulting row is a hash
whose keys are named the same as the column name.
- •
- innotop filters the rows, removing those that don't need to be displayed.
See "FILTERS".
- •
- innotop sorts the rows. See "SORTING".
- •
- innotop groups the rows together, if specified. See
"GROUPING".
- •
- innotop colorizes the rows. See "COLORS".
- •
- innotop transforms the column values in each row. See
"TRANSFORMATIONS".
- •
- innotop optionally pivots the rows (see "PIVOTING"), then
filters and sorts them.
- •
- innotop formats and justifies the rows as a table. During this step,
innotop applies further formatting to the column values, including
alignment, maximum and minimum widths. innotop also does final error
checking to ensure there are no crashes due to undefined values. innotop
then adds a caption if specified, and the table is ready to print.
The lifecycle is slightly different if the table is pivoted, as noted above. To
clarify, if the table is pivoted, the process is extract, group, transform,
pivot, filter, sort, create. If it's not pivoted, the process is extract,
filter, sort, group, color, transform, create. This slightly convoluted
process doesn't map all that well to SQL, but pivoting complicates things
pretty thoroughly. Roughly speaking, filtering and sorting happen as late as
needed to effect the final result as you might expect, but as early as
possible for efficiency.
Each built-in table is described below:
- adaptive_hash_index
- Displays data about InnoDB's adaptive hash index. Data source:
"STATUS_VARIABLES".
- buffer_pool
- Displays data about InnoDB's buffer pool. Data source:
"STATUS_VARIABLES".
- cmd_summary
- Displays weighted status variables. Data source:
"STATUS_VARIABLES".
- deadlock_locks
- Shows which locks were held and waited for by the last detected deadlock.
Data source: "DEADLOCK_LOCKS".
- deadlock_transactions
- Shows transactions involved in the last detected deadlock. Data source:
"DEADLOCK_TRANSACTIONS".
- explain
- Shows the output of EXPLAIN. Data source: "EXPLAIN".
- file_io_misc
- Displays data about InnoDB's file and I/O operations. Data source:
"STATUS_VARIABLES".
- fk_error
- Displays various data about InnoDB's last foreign key error. Data source:
"STATUS_VARIABLES".
- innodb_locks
- Displays InnoDB locks. Data source: "INNODB_LOCKS".
- innodb_transactions
- Displays data about InnoDB's current transactions. Data source:
"INNODB_TRANSACTIONS".
- insert_buffers
- Displays data about InnoDB's insert buffer. Data source:
"STATUS_VARIABLES".
- io_threads
- Displays data about InnoDB's I/O threads. Data source:
"IO_THREADS".
- log_statistics
- Displays data about InnoDB's logging system. Data source:
"STATUS_VARIABLES".
- master_status
- Displays replication master status. Data source:
"STATUS_VARIABLES".
- open_tables
- Displays open tables. Data source: "OPEN_TABLES".
- page_statistics
- Displays InnoDB page statistics. Data source:
"STATUS_VARIABLES".
- pending_io
- Displays InnoDB pending I/O operations. Data source:
"STATUS_VARIABLES".
- processlist
- Displays current MySQL processes (threads/connections). Data source:
"PROCESSLIST".
- q_header
- Displays various status values. Data source:
"STATUS_VARIABLES".
- row_operation_misc
- Displays data about InnoDB's row operations. Data source:
"STATUS_VARIABLES".
- row_operations
- Displays data about InnoDB's row operations. Data source:
"STATUS_VARIABLES".
- semaphores
- Displays data about InnoDB's semaphores and mutexes. Data source:
"STATUS_VARIABLES".
- slave_io_status
- Displays data about the slave I/O thread. Data source:
"STATUS_VARIABLES".
- slave_sql_status
- Displays data about the slave SQL thread. Data source:
"STATUS_VARIABLES".
- t_header
- Displays various InnoDB status values. Data source:
"STATUS_VARIABLES".
- var_status
- Displays user-configurable data. Data source:
"STATUS_VARIABLES".
- wait_array
- Displays data about InnoDB's OS wait array. Data source:
"OS_WAIT_ARRAY".
COLUMNS¶
Columns belong to tables. You can choose a table's columns by pressing the '^'
key, which starts the "TABLE EDITOR" and lets you choose and edit
columns. Pressing 'e' from within the table editor lets you edit the column's
properties:
- •
- hdr: a column header. This appears in the first row of the table.
- •
- just: justification. '-' means left-justified and '' means
right-justified, just as with printf formatting codes (not a
coincidence).
- •
- dec: whether to further align the column on the decimal point.
- •
- num: whether the column is numeric. This affects how values are sorted
(lexically or numerically).
- •
- label: a small note about the column, which appears in dialogs that help
the user choose columns.
- •
- src: an expression that innotop uses to extract the column's data from its
source (see "DATA SOURCES"). See "EXPRESSIONS" for
more on expressions.
- •
- minw: specifies a minimum display width. This helps stabilize the display,
which makes it easier to read if the data is changing frequently.
- •
- maxw: similar to minw.
- •
- trans: a list of column transformations. See
"TRANSFORMATIONS".
- •
- agg: an aggregate function. See "GROUPING". The default is
"first".
- •
- aggonly: controls whether the column only shows when grouping is enabled
on the table (see "GROUPING"). By default, this is disabled.
This means columns will always be shown by default, whether grouping is
enabled or not. If a column's aggonly is set true, the column will appear
when you toggle grouping on the table. Several columns are set this way,
such as the count column on "processlist" and
"innodb_transactions", so you don't see a count when the
grouping isn't enabled, but you do when it is.
FILTERS¶
Filters remove rows from the display. They behave much like a WHERE clause in
SQL. innotop has several built-in filters, which remove irrelevant information
like inactive queries, but you can define your own as well. innotop also lets
you create quick-filters, which do not get saved to the configuration file,
and are just an easy way to quickly view only some rows.
You can enable or disable a filter on any table. Press the '%' key (mnemonic: %
looks kind of like a line being filtered between two circles) and choose which
table you want to filter, if asked. You'll then see a list of possible filters
and a list of filters currently enabled for that table. Type the names of
filters you want to apply and press Enter.
USER-DEFINED FILTERS
If you type a name that doesn't exist, innotop will prompt you to create the
filter. Filters are easy to create if you know Perl, and not hard if you
don't. What you're doing is creating a subroutine that returns true if the row
should be displayed. The row is a hash reference passed to your subroutine as
$set.
For example, imagine you want to filter the processlist table so you only see
queries that have been running more than five minutes. Type a new name for
your filter, and when prompted for the subroutine body, press TAB to initiate
your terminal's auto-completion. You'll see the names of the columns in the
"processlist" table (innotop generally tries to help you with
auto-completion lists). You want to filter on the 'time' column. Type the text
"$set->{time} > 300" to return true when the query is more
than five minutes old. That's all you need to do.
In other words, the code you're typing is surrounded by an implicit context,
which looks like this:
sub filter {
my ( $set ) = @_;
# YOUR CODE HERE
}
If your filter doesn't work, or if something else suddenly behaves differently,
you might have made an error in your filter, and innotop is silently catching
the error. Try enabling "debug" to make innotop throw an error
instead.
QUICK-FILTERS
innotop's quick-filters are a shortcut to create a temporary filter that doesn't
persist when you restart innotop. To create a quick-filter, press the '/' key.
innotop will prompt you for the column name and filter text. Again, you can
use auto-completion on column names. The filter text can be just the text you
want to "search for." For example, to filter the
"processlist" table on queries that refer to the products table,
type '/' and then 'info product'.
The filter text can actually be any Perl regular expression, but of course a
literal string like 'product' works fine as a regular expression.
Behind the scenes innotop compiles the quick-filter into a specially tagged
filter that is otherwise like any other filter. It just isn't saved to the
configuration file.
To clear quick-filters, press the '\' key and innotop will clear them all at
once.
SORTING¶
innotop has sensible built-in defaults to sort the most important rows to the
top of the table. Like anything else in innotop, you can customize how any
table is sorted.
To start the sort dialog, start the "TABLE EDITOR" with the '^' key,
choose a table if necessary, and press the 's' key. You'll see a list of
columns you can use in the sort expression and the current sort expression, if
any. Enter a list of columns by which you want to sort and press Enter. If you
want to reverse sort, prefix the column name with a minus sign. For example,
if you want to sort by column a ascending, then column b descending, type 'a
-b'. You can also explicitly add a + in front of columns you want to sort
ascending, but it's not required.
Some modes have keys mapped to open this dialog directly, and to quickly reverse
sort direction. Press '?' as usual to see which keys are mapped in any mode.
GROUPING¶
innotop can group, or aggregate, rows together (the terms are used
interchangeably). This is quite similar to an SQL GROUP BY clause. You can
specify to group on certain columns, or if you don't specify any, the entire
set of rows is treated as one group. This is quite like SQL so far, but unlike
SQL, you can also select un-grouped columns. innotop actually aggregates every
column. If you don't explicitly specify a grouping function, the default is
'first'. This is basically a convenience so you don't have to specify an
aggregate function for every column you want in the result.
You can quickly toggle grouping on a table with the '=' key, which toggles its
aggregate property. This property doesn't persist to the config file.
The columns by which the table is grouped are specified in its group_by
property. When you turn grouping on, innotop places the group_by columns at
the far left of the table, even if they're not supposed to be visible. The
rest of the visible columns appear in order after them.
Two tables have default group_by lists and a count column built in:
"processlist" and "innodb_transactions". The grouping is
by connection and status, so you can quickly see how many queries or
transactions are in a given status on each server you're monitoring. The time
columns are aggregated as a sum; other columns are left at the default 'first'
aggregation.
By default, the table shown in "S: Variables & Status" mode also
uses grouping so you can monitor variables and status across many servers. The
default aggregation function in this mode is 'avg'.
Valid grouping functions are defined in the %agg_funcs hash. They include
- first
- Returns the first element in the group.
- count
- Returns the number of elements in the group, including undefined elements,
much like SQL's COUNT(*).
- avg
- Returns the average of defined elements in the group.
- sum
- Returns the sum of elements in the group.
Here's an example of grouping at work. Suppose you have a very busy server with
hundreds of open connections, and you want to see how many connections are in
what status. Using the built-in grouping rules, you can press 'Q' to enter
"Q: Query List" mode. Press '=' to toggle grouping (if necessary,
select the "processlist" table when prompted).
Your display might now look like the following:
Query List (? for help) localhost, 32:33, 0.11 QPS, 1 thd, 5.0.38-log
CXN Cmd Cnt ID User Host Time Query
localhost Query 49 12933 webusr localhost 19:38 SELECT * FROM
localhost Sending Da 23 2383 webusr localhost 12:43 SELECT col1,
localhost Sleep 120 140 webusr localhost 5:18:12
localhost Statistics 12 19213 webusr localhost 01:19 SELECT * FROM
That's actually quite a worrisome picture. You've got a lot of idle connections
(Sleep), and some connections executing queries (Query and Sending Data).
That's okay, but you also have a lot in Statistics status, collectively
spending over a minute. That means the query optimizer is having a really hard
time optimizing your statements. Something is wrong; it should normally take
milliseconds to optimize queries. You might not have seen this pattern if you
didn't look at your connections in aggregate. (This is a made-up example, but
it can happen in real life).
PIVOTING¶
innotop can pivot a table for more compact display, similar to a Pivot Table in
a spreadsheet (also known as a crosstab). Pivoting a table makes columns into
rows. Assume you start with this table:
foo bar
=== ===
1 3
2 4
After pivoting, the table will look like this:
name set0 set1
==== ==== ====
foo 1 2
bar 3 4
To get reasonable results, you might need to group as well as pivoting. innotop
currently does this for "S: Variables & Status" mode.
COLORS¶
By default, innotop highlights rows with color so you can see at a glance which
rows are more important. You can customize the colorization rules and add your
own to any table. Open the table editor with the '^' key, choose a table if
needed, and press 'o' to open the color editor dialog.
The color editor dialog displays the rules applied to the table, in the order
they are evaluated. Each row is evaluated against each rule to see if the rule
matches the row; if it does, the row gets the specified color, and no further
rules are evaluated. The rules look like the following:
state eq Locked black on_red
cmd eq Sleep white
user eq system user white
cmd eq Connect white
cmd eq Binlog Dump white
time > 600 red
time > 120 yellow
time > 60 green
time > 30 cyan
This is the default rule set for the "processlist" table. In order of
priority, these rules make locked queries black on a red background,
"gray out" connections from replication and sleeping queries, and
make queries turn from cyan to red as they run longer.
(For some reason, the ANSI color code "white" is actually a light
gray. Your terminal's display may vary; experiment to find colors you like).
You can use keystrokes to move the rules up and down, which re-orders their
priority. You can also delete rules and add new ones. If you add a new rule,
innotop prompts you for the column, an operator for the comparison, a value
against which to compare the column, and a color to assign if the rule
matches. There is auto-completion and prompting at each step.
The value in the third step needs to be correctly quoted. innotop does not try
to quote the value because it doesn't know whether it should treat the value
as a string or a number. If you want to compare the column against a string,
as for example in the first rule above, you should enter 'Locked' surrounded
by quotes. If you get an error message about a bareword, you probably should
have quoted something.
EXPRESSIONS¶
Expressions are at the core of how innotop works, and are what enables you to
extend innotop as you wish. Recall the table lifecycle explained in
"TABLES". Expressions are used in the earliest step, where it
extracts values from a data source to form rows.
It does this by calling a subroutine for each column, passing it the source data
set, a set of current values, and a set of previous values. These are all
needed so the subroutine can calculate things like the difference between this
tick and the previous tick.
The subroutines that extract the data from the set are compiled from
expressions. This gives significantly more power than just naming the values
to fill the columns, because it allows the column's value to be calculated
from whatever data is necessary, but avoids the need to write complicated and
lengthy Perl code.
innotop begins with a string of text that can look as simple as a value's name
or as complicated as a full-fledged Perl expression. It looks at each
'bareword' token in the string and decides whether it's supposed to be a key
into the $set hash. A bareword is an unquoted value that isn't already
surrounded by code-ish things like dollar signs or curly brackets. If innotop
decides that the bareword isn't a function or other valid Perl code, it
converts it into a hash access. After the whole string is processed, innotop
compiles a subroutine, like this:
sub compute_column_value {
my ( $set, $cur, $pre ) = @_;
my $val = # EXPANDED STRING GOES HERE
return $val;
}
Here's a concrete example, taken from the header table "q_header" in
"Q: Query List" mode. This expression calculates the qps, or Queries
Per Second, column's values, from the values returned by SHOW STATUS:
Questions/Uptime_hires
innotop decides both words are barewords, and transforms this expression into
the following Perl code:
$set->{Questions}/$set->{Uptime_hires}
When surrounded by the rest of the subroutine's code, this is executable Perl
that calculates a high-resolution queries-per-second value.
The arguments to the subroutine are named $set, $cur, and $pre. In most cases,
$set and $cur will be the same values. However, if "status_inc" is
set, $cur will not be the same as $set, because $set will already contain
values that are the incremental difference between $cur and $pre.
Every column in innotop is computed by subroutines compiled in the same fashion.
There is no difference between innotop's built-in columns and user-defined
columns. This keeps things consistent and predictable.
Transformations change how a value is rendered. For example, they can take a
number of seconds and display it in H:M:S format. The following
transformations are defined:
- commify
- Adds commas to large numbers every three decimal places.
- dulint_to_int
- Accepts two unsigned integers and converts them into a single longlong.
This is useful for certain operations with InnoDB, which uses two integers
as transaction identifiers, for example.
- no_ctrl_char
- Removes quoted control characters from the value. This is affected by the
"charset" configuration variable.
This transformation only operates within quoted strings, for example, values
to a SET clause in an UPDATE statement. It will not alter the UPDATE
statement, but will collapse the quoted string to [BINARY] or [TEXT],
depending on the charset.
- percent
- Converts a number to a percentage by multiplying it by two, formatting it
with "num_digits" digits after the decimal point, and optionally
adding a percent sign (see "show_percent").
- secs_to_time
- Formats a number of seconds as time in days+hours:minutes:seconds
format.
- set_precision
- Formats numbers with "num_digits" number of digits after the
decimal point.
- shorten
- Formats a number as a unit of 1024 (k/M/G/T) and with
"num_digits" number of digits after the decimal point.
TABLE EDITOR¶
The innotop table editor lets you customize tables with keystrokes. You start
the table editor with the '^' key. If there's more than one table on the
screen, it will prompt you to choose one of them. Once you do, innotop will
show you something like this:
Editing table definition for Buffer Pool. Press ? for help, q to quit.
name hdr label src
cxn CXN Connection from which cxn
buf_pool_size Size Buffer pool size IB_bp_buf_poo
buf_free Free Bufs Buffers free in the b IB_bp_buf_fre
pages_total Pages Pages total IB_bp_pages_t
pages_modified Dirty Pages Pages modified (dirty IB_bp_pages_m
buf_pool_hit_rate Hit Rate Buffer pool hit rate IB_bp_buf_poo
total_mem_alloc Memory Total memory allocate IB_bp_total_m
add_pool_alloc Add'l Pool Additonal pool alloca IB_bp_add_poo
The first line shows which table you're editing, and reminds you again to press
'?' for a list of key mappings. The rest is a tabular representation of the
table's columns, because that's likely what you're trying to edit. However,
you can edit more than just the table's columns; this screen can start the
filter editor, color rule editor, and more.
Each row in the display shows a single column in the table you're editing, along
with a couple of its properties such as its header and source expression (see
"EXPRESSIONS").
The key mappings are Vim-style, as in many other places. Pressing 'j' and 'k'
moves the highlight up or down. You can then (d)elete or (e)dit the
highlighted column. You can also (a)dd a column to the table. This actually
just activates one of the columns already defined for the table; it prompts
you to choose from among the columns available but not currently displayed.
Finally, you can re-order the columns with the '+' and '-' keys.
You can do more than just edit the columns with the table editor, you can also
edit other properties, such as the table's sort expression and group-by
expression. Press '?' to see the full list, of course.
If you want to really customize and create your own column, as opposed to just
activating a built-in one that's not currently displayed, press the (n)ew key,
and innotop will prompt you for the information it needs:
- •
- The column name: this needs to be a word without any funny characters,
e.g. just letters, numbers and underscores.
- •
- The column header: this is the label that appears at the top of the
column, in the table header. This can have spaces and funny characters,
but be careful not to make it too wide and waste space on-screen.
- •
- The column's data source: this is an expression that determines what data
from the source (see "TABLES") innotop will put into the column.
This can just be the name of an item in the source, or it can be a more
complex expression, as described in "EXPRESSIONS".
Once you've entered the required data, your table has a new column. There is no
difference between this column and the built-in ones; it can have all the same
properties and behaviors. innotop will write the column's definition to the
configuration file, so it will persist across sessions.
Here's an example: suppose you want to track how many times your slaves have
retried transactions. According to the MySQL manual, the
Slave_retried_transactions status variable gives you that data: "The
total number of times since startup that the replication slave SQL thread has
retried transactions. This variable was added in version 5.0.4." This is
appropriate to add to the "slave_sql_status" table.
To add the column, switch to the replication-monitoring mode with the 'M' key,
and press the '^' key to start the table editor. When prompted, choose
slave_sql_status as the table, then press 'n' to create the column. Type
'retries' as the column name, 'Retries' as the column header, and
'Slave_retried_transactions' as the source. Now the column is created, and you
see the table editor screen again. Press 'q' to exit the table editor, and
you'll see your column at the end of the table.
VARIABLE SETS¶
Variable sets are used in "S: Variables & Status" mode to define
more easily what variables you want to monitor. Behind the scenes they are
compiled to a list of expressions, and then into a column list so they can be
treated just like columns in any other table, in terms of data extraction and
transformations. However, you're protected from the tedious details by a
syntax that ought to feel very natural to you: a SQL SELECT list.
The data source for variable sets, and indeed the entire S mode, is the
combination of SHOW STATUS, SHOW VARIABLES, and SHOW INNODB STATUS. Imagine
that you had a huge table with one column per variable returned from those
statements. That's the data source for variable sets. You can now query this
data source just like you'd expect. For example:
Questions, Uptime, Questions/Uptime as QPS
Behind the scenes innotop will split that variable set into three expressions,
compile them and turn them into a table definition, then extract as usual.
This becomes a "variable set," or a "list of variables you want
to monitor."
innotop lets you name and save your variable sets, and writes them to the
configuration file. You can choose which variable set you want to see with the
'c' key, or activate the next and previous sets with the '>' and '<'
keys. There are many built-in variable sets as well, which should give you a
good start for creating your own. Press 'e' to edit the current variable set,
or just to see how it's defined. To create a new one, just press 'c' and type
its name.
You may want to use some of the functions listed in "TRANSFORMATIONS"
to help format the results. In particular, "set_precision" is often
useful to limit the number of digits you see. Extending the above example,
here's how:
Questions, Uptime, set_precision(Questions/Uptime) as QPS
Actually, this still needs a little more work. If your "interval" is
less than one second, you might be dividing by zero because Uptime is
incremental in this mode by default. Instead, use Uptime_hires:
Questions, Uptime, set_precision(Questions/Uptime_hires) as QPS
This example is simple, but it shows how easy it is to choose which variables
you want to monitor.
PLUGINS¶
innotop has a simple but powerful plugin mechanism by which you can extend or
modify its existing functionality, and add new functionality. innotop's plugin
functionality is event-based: plugins register themselves to be called when
events happen. They then have a chance to influence the event.
An innotop plugin is a Perl module placed in innotop's "plugin_dir"
directory. On UNIX systems, you can place a symbolic link to the module
instead of putting the actual file there. innotop automatically discovers the
file. If there is a corresponding entry in the "plugins"
configuration file section, innotop loads and activates the plugin.
The module must conform to innotop's plugin interface. Additionally, the source
code of the module must be written in such a way that innotop can inspect the
file and determine the package name and description.
Package Source Convention¶
innotop inspects the plugin module's source to determine the Perl package name.
It looks for a line of the form "package Foo;" and if found,
considers the plugin's package name to be Foo. Of course the package name can
be a valid Perl package name, with double semicolons and so on.
It also looks for a description in the source code, to make the plugin editor
more human-friendly. The description is a comment line of the form "#
description: Foo", where "Foo" is the text innotop will
consider to be the plugin's description.
Plugin Interface¶
The innotop plugin interface is quite simple: innotop expects the plugin to be
an object-oriented module it can call certain methods on. The methods are
- new(%variables)
- This is the plugin's constructor. It is passed a hash of innotop's
variables, which it can manipulate (see "Plugin Variables"). It
must return a reference to the newly created plugin object.
At construction time, innotop has only loaded the general configuration and
created the default built-in variables with their default contents (which
is quite a lot). Therefore, the state of the program is exactly as in the
innotop source code, plus the configuration variables from the
"general" section in the config file.
If your plugin manipulates the variables, it is changing global data, which
is shared by innotop and all plugins. Plugins are loaded in the order
they're listed in the config file. Your plugin may load before or after
another plugin, so there is a potential for conflict or interaction
between plugins if they modify data other plugins use or modify.
- register_for_events()
- This method must return a list of events in which the plugin is
interested, if any. See "Plugin Events" for the defined events.
If the plugin returns an event that's not defined, the event is
ignored.
- event handlers
- The plugin must implement a method named the same as each event for which
it has registered. In other words, if the plugin returns qw(foo bar) from
register_for_events(), it must have foo() and bar()
methods. These methods are callbacks for the events. See "Plugin
Events" for more details about each event.
Plugin Variables¶
The plugin's constructor is passed a hash of innotop's variables, which it can
manipulate. It is probably a good idea if the plugin object saves a copy of it
for later use. The variables are defined in the innotop variable
%pluggable_vars, and are as follows:
- action_for
- A hashref of key mappings. These are innotop's global hot-keys.
- agg_funcs
- A hashref of functions that can be used for grouping. See
"GROUPING".
- config
- The global configuration hash.
- connections
- A hashref of connection specifications. These are just specifications of
how to connect to a server.
- dbhs
- A hashref of innotop's database connections. These are actual DBI
connection objects.
- filters
- A hashref of filters applied to table rows. See "FILTERS" for
more.
- modes
- A hashref of modes. See "MODES" for more.
- server_groups
- A hashref of server groups. See "SERVER GROUPS".
- tbl_meta
- A hashref of innotop's table meta-data, with one entry per table (see
"TABLES" for more information).
- trans_funcs
- A hashref of transformation functions. See
"TRANSFORMATIONS".
- var_sets
- A hashref of variable sets. See "VARIABLE SETS".
Plugin Events¶
Each event is defined somewhere in the innotop source code. When innotop runs
that code, it executes the callback function for each plugin that expressed
its interest in the event. innotop passes some data for each event. The events
are defined in the %event_listener_for variable, and are as follows:
- extract_values($set, $cur, $pre, $tbl)
- This event occurs inside the function that extracts values from a data
source. The arguments are the set of values, the current values, the
previous values, and the table name.
- set_to_tbl
- Events are defined at many places in this subroutine, which is responsible
for turning an arrayref of hashrefs into an arrayref of lines that can be
printed to the screen. The events all pass the same data: an arrayref of
rows and the name of the table being created. The events are
set_to_tbl_pre_filter, set_to_tbl_pre_sort,set_to_tbl_pre_group,
set_to_tbl_pre_colorize, set_to_tbl_pre_transform, set_to_tbl_pre_pivot,
set_to_tbl_pre_create, set_to_tbl_post_create.
- draw_screen($lines)
- This event occurs inside the subroutine that prints the lines to the
screen. $lines is an arrayref of strings.
Simple Plugin Example¶
The easiest way to explain the plugin functionality is probably with a simple
example. The following module adds a column to the beginning of every table
and sets its value to 1.
use strict;
use warnings FATAL => 'all';
package Innotop::Plugin::Example;
# description: Adds an 'example' column to every table
sub new {
my ( $class, %vars ) = @_;
# Store reference to innotop's variables in $self
my $self = bless { %vars }, $class;
# Design the example column
my $col = {
hdr => 'Example',
just => '',
dec => 0,
num => 1,
label => 'Example',
src => 'example', # Get data from this column in the data source
tbl => '',
trans => [],
};
# Add the column to every table.
my $tbl_meta = $vars{tbl_meta};
foreach my $tbl ( values %$tbl_meta ) {
# Add the column to the list of defined columns
$tbl->{cols}->{example} = $col;
# Add the column to the list of visible columns
unshift @{$tbl->{visible}}, 'example';
}
# Be sure to return a reference to the object.
return $self;
}
# I'd like to be called when a data set is being rendered into a table, please.
sub register_for_events {
my ( $self ) = @_;
return qw(set_to_tbl_pre_filter);
}
# This method will be called when the event fires.
sub set_to_tbl_pre_filter {
my ( $self, $rows, $tbl ) = @_;
# Set the example column's data source to the value 1.
foreach my $row ( @$rows ) {
$row->{example} = 1;
}
}
1;
Plugin Editor¶
The plugin editor lets you view the plugins innotop discovered and activate or
deactivate them. Start the editor by pressing $ to start the configuration
editor from any mode. Press the 'p' key to start the plugin editor. You'll see
a list of plugins innotop discovered. You can use the 'j' and 'k' keys to move
the highlight to the desired one, then press the * key to toggle it active or
inactive. Exit the editor and restart innotop for the changes to take effect.
SQL STATEMENTS¶
innotop uses a limited set of SQL statements to retrieve data from MySQL for
display. The statements are customized depending on the server version against
which they are executed; for example, on MySQL 5 and newer, INNODB_STATUS
executes "SHOW ENGINE INNODB STATUS", while on earlier versions it
executes "SHOW INNODB STATUS". The statements are as follows:
Statement SQL executed
=================== ===============================
INNODB_STATUS SHOW [ENGINE] INNODB STATUS
KILL_CONNECTION KILL
KILL_QUERY KILL QUERY
OPEN_TABLES SHOW OPEN TABLES
PROCESSLIST SHOW FULL PROCESSLIST
SHOW_MASTER_LOGS SHOW MASTER LOGS
SHOW_MASTER_STATUS SHOW MASTER STATUS
SHOW_SLAVE_STATUS SHOW SLAVE STATUS
SHOW_STATUS SHOW [GLOBAL] STATUS
SHOW_VARIABLES SHOW [GLOBAL] VARIABLES
DATA SOURCES¶
Each time innotop extracts values to create a table (see "EXPRESSIONS"
and "TABLES"), it does so from a particular data source. Largely
because of the complex data extracted from SHOW INNODB STATUS, this is
slightly messy. SHOW INNODB STATUS contains a mixture of single values and
repeated values that form nested data sets.
Whenever innotop fetches data from MySQL, it adds two extra bits to each set:
cxn and Uptime_hires. cxn is the name of the connection from which the data
came. Uptime_hires is a high-resolution version of the server's Uptime status
variable, which is important if your "interval" setting is
sub-second.
Here are the kinds of data sources from which data is extracted:
- STATUS_VARIABLES
- This is the broadest category, into which the most kinds of data fall. It
begins with the combination of SHOW STATUS and SHOW VARIABLES, but other
sources may be included as needed, for example, SHOW MASTER STATUS and
SHOW SLAVE STATUS, as well as many of the non-repeated values from SHOW
INNODB STATUS.
- DEADLOCK_LOCKS
- This data is extracted from the transaction list in the LATEST DETECTED
DEADLOCK section of SHOW INNODB STATUS. It is nested two levels deep:
transactions, then locks.
- DEADLOCK_TRANSACTIONS
- This data is from the transaction list in the LATEST DETECTED DEADLOCK
section of SHOW INNODB STATUS. It is nested one level deep.
- EXPLAIN
- This data is from the result set returned by EXPLAIN.
- INNODB_TRANSACTIONS
- This data is from the TRANSACTIONS section of SHOW INNODB STATUS.
- IO_THREADS
- This data is from the list of threads in the the FILE I/O section of SHOW
INNODB STATUS.
- INNODB_LOCKS
- This data is from the TRANSACTIONS section of SHOW INNODB STATUS and is
nested two levels deep.
- OPEN_TABLES
- This data is from SHOW OPEN TABLES.
- PROCESSLIST
- This data is from SHOW FULL PROCESSLIST.
- OS_WAIT_ARRAY
- This data is from the SEMAPHORES section of SHOW INNODB STATUS and is
nested one level deep. It comes from the lines that look like this:
--Thread 1568861104 has waited at btr0cur.c line 424 ....
MYSQL PRIVILEGES¶
- •
- You must connect to MySQL as a user who has the SUPER privilege for many
of the functions.
- •
- If you don't have the SUPER privilege, you can still run some functions,
but you won't necessarily see all the same data.
- •
- You need the PROCESS privilege to see the list of currently running
queries in Q mode.
- •
- You need special privileges to start and stop slave servers.
- •
- You need appropriate privileges to create and drop the deadlock tables if
needed (see "SERVER CONNECTIONS").
SYSTEM REQUIREMENTS¶
You need Perl to run innotop, of course. You also need a few Perl modules: DBI,
DBD::mysql, Term::ReadKey, and Time::HiRes. These should be included with most
Perl distributions, but in case they are not, I recommend using versions
distributed with your operating system or Perl distribution, not from CPAN.
Term::ReadKey in particular has been known to cause problems if installed from
CPAN.
If you have Term::ANSIColor, innotop will use it to format headers more readably
and compactly. (Under Microsoft Windows, you also need Win32::Console::ANSI
for terminal formatting codes to be honored). If you install Term::ReadLine,
preferably Term::ReadLine::Gnu, you'll get nice auto-completion support.
I run innotop on Gentoo GNU/Linux, Debian and Ubuntu, and I've had feedback from
people successfully running it on Red Hat, CentOS, Solaris, and Mac OSX. I
don't see any reason why it won't work on other UNIX-ish operating systems,
but I don't know for sure. It also runs on Windows under ActivePerl without
problem.
innotop has been used on MySQL versions 3.23.58, 4.0.27, 4.1.0, 4.1.22, 5.0.26,
5.1.15, and 5.2.3. If it doesn't run correctly for you, that is a bug that
should be reported.
FILES¶
$HOMEDIR/.innotop and/or /etc/innotop are used to store configuration
information. Files include the configuration file innotop.conf, the core_dump
file which contains verbose error messages if "debug" is enabled,
and the plugins/ subdirectory.
GLOSSARY OF TERMS¶
- tick
- A tick is a refresh event, when innotop re-fetches data from connections
and displays it.
ACKNOWLEDGEMENTS¶
The following people and organizations are acknowledged for various reasons.
Hopefully no one has been forgotten.
Allen K. Smith, Aurimas Mikalauskas, Bartosz Fenski, Brian Miezejewski,
Christian Hammers, Cyril Scetbon, Dane Miller, David Multer, Dr. Frank
Ullrich, Giuseppe Maxia, Google.com Site Reliability Engineers, Google Code,
Jan Pieter Kunst, Jari Aalto, Jay Pipes, Jeremy Zawodny, Johan Idren, Kristian
Kohntopp, Lenz Grimmer, Maciej Dobrzanski, Michiel Betel, MySQL AB, Paul
McCullagh, Sebastien Estienne, Sourceforge.net, Steven Kreuzer, The Gentoo
MySQL Team, Trevor Price, Yaar Schnitman, and probably more people that have
not been included.
(If your name has been misspelled, it's probably out of fear of putting
international characters into this documentation; earlier versions of Perl
might not be able to compile it then).
COPYRIGHT, LICENSE AND WARRANTY¶
This program is copyright (c) 2006 Baron Schwartz. Feedback and improvements are
welcome.
THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License. On UNIX and similar
systems, you can issue `man perlgpl' or `man perlartistic' to read these
licenses.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA.
Execute innotop and press '!' to see this information at any time.
AUTHOR¶
Originally written by Baron Schwartz; currently maintained by Aaron Racine.
BUGS¶
You can report bugs, ask for improvements, and get other help and support at
<
http://code.google.com/p/innotop/>. There are mailing lists, a source
code browser, a bug tracker, etc. Please use these instead of contacting the
maintainer or author directly, as it makes our job easier and benefits others
if the discussions are permanent and public. Of course, if you need to contact
us in private, please do.