NAME

SYNOPSIS

 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 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

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

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.

--timestamp

In -n mode, write a timestamp either before every screenful of output, or if the option is given twice, at the start of every line. The format is controlled by the timeformat config variable.

--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

• 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

A: Health Dashboard

This mode displays a single table with one row per monitored server. The columns show essential overview information about the server's health, and coloration rules show whether replication is running or if there are any very long-running queries or excessive replication delay.

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.

K: InnoDB Lock Waits

This mode shows information from InnoDB plugin's transaction and locking tables. You can use it to find when a transaction is waiting for another, and kill the blocking transaction. It displays the "innodb_blocked_blocker" table.

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.

U: User Statistics

This mode displays data that's available in Percona's enhanced version of MySQL (also known as Percona Server with XtraDB). Specifically, it makes it easy to enable and disable the so-called "user statistics." This feature gathers stats on clients, threads, users, tables, and indexes and makes them available as INFORMATION_SCHEMA tables. These are invaluable for understanding what your server is doing. They are also available in MariaDB.

The statistics supported so far are only from the TABLE_STATISTICS and INDEX_STATISTICS tables added by Percona. There are three views: one of table stats, one of index stats (which can be aggregated with the = key), and one of both.

The server doesn't gather these stats by default. You have to set the variable userstat_running to turn it on. You can do this easily with innotop from U mode, with the 's' key.

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

SERVER ADMINISTRATION

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.

in "U: User Statistics" mode, you can use the 's' key to start and stop the collection of the statistics data for TABLE_STATISTICS and similar.

SERVER CONNECTIONS

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

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

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

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

• 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

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 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.

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

• 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.

 sub filter {
    my ( $set ) = @_;
    # YOUR CODE HERE
 }

 sub filter {
    my ( $set ) = @_;
    $set->{info} =~ m/product/;
 }

 1. /
 2. cmd ^(?!Gandalf)

 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

 foo bar
 === ===
 1   3
 2   4

 name set0 set1
 ==== ==== ====
 foo  1    2
 bar  3    4

 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

 sub compute_column_value {
    my ( $set, $cur, $pre ) = @_;
    my $val = # EXPANDED STRING GOES HERE
    return $val;
 }

 Queries/Uptime_hires

 $set->{Queries}/$set->{Uptime_hires}

 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   Additional pool alloc  IB_bp_add_poo

VARIABLE SETS

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:

 Queries, Uptime, Queries/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:

 Queries, Uptime, set_precision(Queries/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:

 Queries, Uptime, set_precision(Queries/Uptime_hires) as QPS

This example is simple, but it shows how easy it is to choose which variables you want to monitor.

PLUGINS

An innotop plugin is a Perl module (.pm) file 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 files named "*.pm". 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.

 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;

SQL STATEMENTS

 Statement           SQL executed
 =================== ===============================
 INDEX_STATISTICS    SELECT * FROM INFORMATION_SCHEMA.INDEX_STATISTICS
 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
 TABLE_STATISTICS    SELECT * FROM INFORMATION_SCHEMA.TABLE_STATISTICS

DATA SOURCES

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_BLOCKED_BLOCKER

This data is from the INFORMATION_SCHEMA tables related to InnoDB locks and the processlist.

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.

MASTER_SLAVE

This data is from the combination of SHOW MASTER STATUS and SHOW SLAVE STATUS.

OPEN_TABLES

This data is from SHOW OPEN TABLES.

PROCESSLIST

This data is from SHOW FULL PROCESSLIST.

PROCESSLIST_STATS

This data is from SHOW FULL PROCESSLIST and computes stats such as the maximum time a user query has been running, and how many user queries are running. A "user query" excludes replication threads.

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

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

GLOSSARY OF TERMS

tick

A tick is a refresh event, when innotop re-fetches data from connections and displays it.

ACKNOWLEDGEMENTS

Aaron Racine, 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 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

BUGS