#!@@PERL@@
# -*- perl -*-

=encoding utf8

=head1 NAME

mysql_ - Munin plugin to display misc MySQL server status

=head1 APPLICABLE SYSTEMS

Any MySQL platform, tested by the authors on:
* MySQL 5.0.51
* MariaDB 5.5.39
* MariaDB-5.5.39(galera).
* MySQL 5.6.12
* MariaDB 10.0.18

Plugins:
* MariaDB-10 Query Response Time: https://mariadb.com/kb/en/mariadb/query_response_time-plugin/

Information Schema tables:
* User statistics - MariaDB-5.2+, OurDelta, Percona Server - https://mariadb.com/kb/en/mariadb/user-statistics

=head1 CONFIGURATION

This script is used to generate data for several graphs. To generate
data for one specific graph, you need to create a symbolic link with a
name like mysql_<GRAPH> to this script.

If you need to run against multiple MySQL instances on the same host,
create your symlinks with names like mysql<N>_<GRAPH> where N is any
non-negative integer. You must also set the env.cachenamespace variable
to a unique value for each group of symlinks.

To get a list of symlinks that can be created, run:

  ./mysql_ suggest

In addition you might need to specify connection parameters in the
plugin configuration to override the defaults. These are the defaults:

  [mysql_*]
    env.mysqlconnection DBI:mysql:information_schema
    env.mysqluser root

Non-default example:

  [mysql_*]
    env.mysqlconnection DBI:mysql:information_schema;host=127.0.0.1;port=3306
    env.mysqluser munin
    env.mysqlpassword geheim
    env.cachenamespace munin_mysql_pri
  [mysql2_*]
    env.mysqlconnection DBI:mysql:information_schema;host=127.0.0.1;port=13306
    env.mysqluser munin
    env.mysqlpassword ryuWyawEv
    env.cachenamespace munin_mysql_alt
  [mysql10_*]
    user munin
    env.mysqluser munin
    env.mysqlconnection DBI:mysql:information_schema;mysql_read_default_file=/etc/munin/.my-10.cnf
    env.cachenamespace munin_mysql_10
    # here the [client] section of /etc/munin/.my-10.cnf is read. socket= can
    # be specified here.

Creating a munin user:

  CREATE USER 'munin'@'localhost' IDENTIFIED BY 'ryuWyawEv';

or with a unix_socket plugin (INSTALL PLUGIN unix_socket SONAME 'auth_socket')

  CREATE USER 'munin'@'localhost' IDENTIFIED WITH unix_socket;

Note: requires 'user munin' in the configuration.

The minimum required priviledges of the munin database user is:

  GRANT PROCESS, REPLICATION CLIENT ON *.* TO 'munin'@'localhost';


Warning and critical values can be set via the environment in the usual way.
For example:

  [mysql_replication]
    env.slave_io_running_warning 0.5
    env.slave_sql_running_warning 0.5
    env.seconds_behind_master_warning 300
    env.seconds_behind_master_critical 600

=head1 DEPENDENCIES

=over

=item Cache::Cache

The plugin uses shared memory to cache the statistics gathered from
MySQL. This ensures minimal inpact on the MySQL server.

=item DBD::mysql

=back

=head1 INTERPRETATION

=head2 InnoDB

The statistics from innodb are mainly collected from the command

  SHOW ENGINE INNODB STATUS

A nice walk through is found at
L<http://www.mysqlperformanceblog.com/2006/07/17/show-innodb-status-walk-through/>

=head2 The graphs

FIX point to relevant sections in the MySQL manual and other www
resources for each graph

=over

=item mysql_replication

slave_io_running and slave_sql_running both translate the "Yes" values to 0 and
anything else to 1 for their respective fields in the "SHOW SLAVE STATUS" output.
This can be used to warn on slave failure if the warning and critical values
are set as seen in a previous section.

=back

=head1 LICENSE

Copyright (C) 2008,2009 Kjell-Magne Øierud

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 dated June, 1991.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

=head1 VERSION

git-master + a few munin modifications

This plugin was downloaded from L<http://github.com/kjellm/munin-mysql/>

=head1 MAGICK MARKERS

  #%# family=auto
  #%# capabilities=suggest autoconf

=cut

use warnings;
use strict;
use utf8;

use English qw( -no_match_vars );
use File::Basename;
use Storable qw(nfreeze thaw);

use Munin::Plugin;

my $has_cache;
my $has_dbi;
my $has_math_bigint;

BEGIN {
    eval { require Cache::SharedMemoryCache; };
    $has_cache = $EVAL_ERROR ? 0 : 1;
    eval { require DBI; DBI->import(); };
    $has_dbi = $EVAL_ERROR ? 0 : 1;
    # Used to append "=> lib 'GMP'" here, but GMP caused segfault on some
    # occasions. Removed as I don't think the tiny performance boost is
    # worth the debugging effort.
    eval { require Math::BigInt; Math::BigInt->import(); };
    $has_math_bigint = $EVAL_ERROR ? 0 : 1;
}


#---------------------------------------------------------------------
#  C O N F I G
#---------------------------------------------------------------------

my %config = (
    'dsn'        => $ENV{'mysqlconnection'} || 'DBI:mysql:information_schema',
    'user'       => $ENV{'mysqluser'}       || 'root',
    'password'   => $ENV{'mysqlpassword'}   || '',
    'cache_namespace' => $ENV{'cachenamespace'} || 'munin_mysql',
);


#---------------------------------------------------------------------
#  C A C H E
#---------------------------------------------------------------------

my %cache_options = (
    'namespace'          => $config{cache_namespace},
    'default_expires_in' => 60,
);

my $shared_memory_cache ;
if ($has_cache)
{
  $shared_memory_cache = Cache::SharedMemoryCache->new(\%cache_options)
    or die("Couldn't instantiate SharedMemoryCache");
}

#---------------------------------------------------------------------
#  G R A P H   D E F I N I T I O N S
#---------------------------------------------------------------------

# These are defaults to save typing in the graph definitions
my %defaults = (
    global_attrs => {
	args   => '--base 1000',
    },
    data_source_attrs => {
	min   => '0',
	type  => 'DERIVE',
	draw  => 'AREASTACK',
    },
);

# %graphs contains the graph definitions, it is indexed on the graph
# name. The information stored for each graph is used for both showing
# data source values and for printing the graph configuration. Each
# graph follows the followingformat:
#
# $graph{NAME} => {
#     config => {
#         # The global attributes for this graph
#         global_attrs => {}
#         # Attributes common to all data sources in this graph
#         data_source_attrs => {}
#     },
#     data_sources => [
#         # NAME - The name of the data source (e.g. variable names
#         #        from SHOW STATUS)
#         # DATA_SOURCE_ATTRS - key-value pairs with data source
#         #                     attributes
#         {name => 'NAME', (DATA_SOURCE_ATTRS)},
#         {...},
#     ],
my %graphs = ();

#---------------------------------------------------------------------

$graphs{bin_relay_log} = {
    config => {
	global_attrs => {
	    title  => 'Binary/Relay Logs',
	    vlabel => 'Log activity',
	},
	data_source_attrs => {
	    draw  => 'LINE1',
	},
    },
    data_sources => [
	{name => 'Binlog_cache_disk_use', label => 'Binlog Cache Disk Use'},
	{name => 'Binlog_cache_use',      label => 'Binlog Cache Use'},
	{name => 'ma_binlog_size',        label => 'Binary Log Space'},
	{name => 'relay_log_space',       label => 'Relay Log Space'},
    ],
};

#-------------------------
$graphs{binlog_groupcommit} = {
    config => {
       global_attrs => {
           title  => 'Binary Log Group Commits',
           vlabel => 'Commits/Groups',
       },
       data_source_attrs => {
           draw  => 'LINE1',
       },
    },
    data_sources => [
       {name => 'Binlog_commits', label => 'Binlog commits'},
       {name => 'Binlog_group_commits',      label => 'Binlog Group Commits'},
       {name => 'Binlog_group_commit_trigger_count', label => 'Binlog Groups because of binlog_commit_wait_count'},
       {name => 'Binlog_group_commit_trigger_timeout', label => 'Binlog Groups because of binlog_commit_wait_usec'},
       {name => 'Binlog_group_commit_trigger_lock_wait', label => 'Binlog Groups because of transactions'},
    ],
};

#---------------------------------------------------------------------

$graphs{commands} = {
    config => {
	global_attrs => {
	    title  => 'Command Counters',
	    vlabel => 'Commands per ${graph_period}',
	    total  => 'Questions',
	},
	data_source_attrs => {},
    },
    data_sources => [
	{name => 'Com_delete',         label => 'Delete'},
	{name => 'Com_insert',         label => 'Insert'},
	{name => 'Com_insert_select',  label => 'Insert select'},
	{name => 'Com_load',           label => 'Load Data'},
	{name => 'Com_replace',        label => 'Replace'},
	{name => 'Com_replace_select', label => 'Replace select'},
	{name => 'Com_select',         label => 'Select'},
	{name => 'Com_update',         label => 'Update'},
	{name => 'Com_update_multi',   label => 'Update multi'},
    ],
};

#---------------------------------------------------------------------

$graphs{connections} = {
    config => {
	global_attrs => {
	    title  => 'Connections',
	    vlabel => 'Connections per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE1',
	},
    },
    data_sources => [
	{name => 'max_connections',      label  => 'Max connections',
					 type   => 'GAUGE',
					 draw   => 'AREA',
					 colour => 'cdcfc4'},
	{name => 'Max_used_connections', label  => 'Max used',
					 type   => 'GAUGE',
					 draw   => 'AREA',
					 colour => 'ffd660'},
	{name => 'Aborted_clients',      label => 'Aborted clients'},
	{name => 'Aborted_connects',     label => 'Aborted connects'},
	{name => 'Threads_connected',    label => 'Threads connected',
					 type  => 'GAUGE'},
	{name => 'Threads_running',      label => 'Threads running',
					 type  => 'GAUGE'},
	{name => 'Connections',          label => 'New connections'},
    ],
};

#---------------------------------------------------------------------

$graphs{files_tables} = {
    config => {
	global_attrs => {
	    title  => 'Files and tables',
	    vlabel => 'Tables',
	},
	data_source_attrs => {
	    type  => 'GAUGE',
	    draw  => 'LINE1',
	},
    },
    data_sources => [
	{name => 'table_open_cache', label  => 'Table cache',
				     draw   => 'AREA',
				     colour => 'cdcfc4'},
	{name => 'Open_files',       label => 'Open files'},
	{name => 'Open_tables',      label => 'Open tables'},
	{name => 'Opened_tables',    label => 'Opened tables',
				     type  => 'DERIVE',
	                             min   => 0},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_bpool} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Buffer Pool',
	    vlabel => 'Pages',
	    args   => '--base 1024',
	},
	data_source_attrs => {
	    draw => 'LINE2',
	    type => 'GAUGE',
	},
    },
    data_sources => [
	{name => 'ib_bpool_size',     label  => 'Buffer pool size',
				      draw   => 'AREA',
				      colour => 'ffd660'},
	{name => 'ib_bpool_dbpages',  label  => 'Database pages',
				      draw   => 'AREA',
				      colour => 'cdcfc4'},
	{name => 'ib_bpool_free',     label => 'Free pages'},
	{name => 'ib_bpool_modpages', label => 'Modified pages'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_bpool_act} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Buffer Pool Activity',
	    vlabel => 'Activity per ${graph_period}',
	    total  => 'Total',
	},
	data_source_attrs => {
	    draw => 'LINE2',
	},
    },
    data_sources => [
	{name => 'ib_bpool_read',    label => 'Pages read'},
	{name => 'ib_bpool_created', label => 'Pages created'},
	{name => 'ib_bpool_written', label => 'Pages written'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_insert_buf} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Insert Buffer',
	    vlabel => 'Activity per ${graph_period}',
	},
	data_source_attrs => {
	    draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'ib_ibuf_inserts',    label => 'Inserts'},
	{name => 'ib_ibuf_merged_rec', label => 'Merged Records'},
	{name => 'ib_ibuf_merges',     label => 'Merges'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_io} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB IO',
	    vlabel => 'IO operations per ${graph_period}',
	},
	data_source_attrs => {
	    draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'ib_io_read',  label => 'File reads'},
	{name => 'ib_io_write', label => 'File writes'},
	{name => 'ib_io_log',   label => 'Log writes'},
	{name => 'ib_io_fsync', label => 'File syncs'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_io_pend} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB IO Pending',
	    vlabel => 'Pending operations',
	},
	data_source_attrs => {
	    draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'ib_iop_log',         label => 'AIO Log'},
	{name => 'ib_iop_sync',        label => 'AIO Sync'},
	{name => 'ib_iop_flush_bpool', label => 'Buf Pool Flush'},
	{name => 'ib_iop_flush_log',   label => 'Log Flushes'},
	{name => 'ib_iop_ibuf_aio',    label => 'Insert Buf AIO Read'},
	{name => 'ib_iop_aioread',     label => 'Normal AIO Reads'},
	{name => 'ib_iop_aiowrite',    label => 'Normal AIO Writes'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_log} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Log',
	    vlabel => 'Log activity per ${graph_period}',
	},
	data_source_attrs => {
	    draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'innodb_log_buffer_size', label  => 'Buffer Size',
					   type   => 'GAUGE',
					   draw   => 'AREA',
					   colour => 'fafd9e'},
	{name => 'ib_log_flush',           label => 'KB Flushed'},
	{name => 'ib_log_written',         label => 'KB Written'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_rows} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Row Operations',
	    vlabel => 'Operations per ${graph_period}',
	    total  => 'Total',
	},
	data_source_attrs => {},
    },
    data_sources => [
	{name => 'Innodb_rows_deleted',  label => 'Deletes'},
	{name => 'Innodb_rows_inserted', label => 'Inserts'},
	{name => 'Innodb_rows_read',     label => 'Reads'},
	{name => 'Innodb_rows_updated',  label => 'Updates'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_semaphores} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Semaphores',
	    vlabel => 'Semaphores per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE1',
	},
    },
    data_sources => [
	{name => 'ib_spin_rounds', label => 'Spin Rounds'},
	{name => 'ib_spin_waits',  label => 'Spin Waits'},
	{name => 'ib_os_waits',    label => 'OS Waits'},
    ],
};

#---------------------------------------------------------------------

$graphs{innodb_tnx} = {
    config => {
	global_attrs => {
	    title  => 'InnoDB Transactions',
	    vlabel => 'Transactions per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE1',
	},
    },
    data_sources => [
	{name => 'ib_tnx', label => 'Transactions created'},
    ],
};

#---------------------------------------------------------------------

$graphs{myisam_indexes} = {
    config => {
	global_attrs => {
	    title  => 'MyISAM Indexes',
	    vlabel => 'Requests per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Key_read_requests',  label => 'Key read requests'},
	{name => 'Key_reads',          label => 'Key reads'},
	{name => 'Key_write_requests', label => 'Key write requests'},
	{name => 'Key_writes',         label => 'Key writes'},
   ],
};

#---------------------------------------------------------------------

$graphs{network_traffic} = {
    config => {
	global_attrs => {
	    title  => 'Network Traffic',
	    args   => '--base 1024',
	    vlabel => 'Bytes received (-) / sent (+) per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Bytes_received', label => 'Bytes transfered',
				   graph => 'no'},
	{name => 'Bytes_sent',     label    => 'Bytes transfered',
				   negative => 'Bytes_received'},
    ],
};

#---------------------------------------------------------------------

$graphs{qcache} = {
    config => {
	global_attrs => {
	    title  => 'Query Cache',
	    vlabel => 'Commands per ${graph_period}',
	},
	data_source_attrs => {
	     draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'Qcache_queries_in_cache', label => 'Queries in cache'},
	{name => 'Qcache_hits',             label => 'Cache hits'},
	{name => 'Qcache_inserts',          label => 'Inserts'},
	{name => 'Qcache_not_cached',       label => 'Not cached'},
	{name => 'Qcache_lowmem_prunes',    label => 'Low-memory prunes'},
    ],
};

#---------------------------------------------------------------------

$graphs{qcache_mem} = {
    config => {
	global_attrs => {
	    title  => 'Query Cache Memory',
	    vlabel => 'Bytes',
	    args   => '--base 1024 --lower-limit 0',
	},
	data_source_attrs => {
	    draw => 'AREA',
	    type => 'GAUGE',
	},
    },
    data_sources => [
	{name => 'query_cache_size',    label => 'Cache size'},
	{name => 'Qcache_free_memory',  label => 'Free mem'},
    ],
};

#---------------------------------------------------------------------

$graphs{replication} = {
    config => {
	global_attrs => {
	    title  => 'Replication',
	    vlabel => 'Activity',
	},
	data_source_attrs => {
	    draw => 'LINE1',
	},
    },
    data_sources => [
	{name => 'slave_io_running',           label => 'Slave IO Running',
					       type  => 'GAUGE',
					       draw  => 'AREA'},
	{name => 'slave_sql_running',          label => 'Slave SQL Running',
					       type  => 'GAUGE',
					       draw  => 'AREA'},
	{name => 'Slave_retried_transactions', label => 'Retried Transactions'},
	{name => 'Slave_open_temp_tables',     label => 'Open Temp Tables'},
	{name => 'seconds_behind_master',      label => 'Secs Behind Master',
					       type  => 'GAUGE'},
    ],
};

#---------------------------------------------------------------------

$graphs{select_types} = {
    config => {
	global_attrs => {
	    title  => 'Select types',
	    vlabel => 'Commands per ${graph_period}',
	    total  => 'Total',
	},
	data_source_attrs => {},
    },
    data_sources => [
	{name => 'Select_full_join',       label => 'Full join'},
	{name => 'Select_full_range_join', label => 'Full range'},
	{name => 'Select_range',           label => 'Range'},
	{name => 'Select_range_check',     label => 'Range check'},
	{name => 'Select_scan',            label => 'Scan'},
    ],
};

#---------------------------------------------------------------------

$graphs{slow} = {
    config => {
	global_attrs => {
	    title  => 'Slow Queries',
	    vlabel => 'Slow queries per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Slow_queries', label => 'Slow queries'},
    ],
};

#---------------------------------------------------------------------

$graphs{sorts} = {
    config => {
	global_attrs => {
	    title  => 'Sorts',
	    vlabel => 'Sorts / ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Sort_rows',         label => 'Rows sorted'},
	{name => 'Sort_range',        label => 'Range'},
	{name => 'Sort_merge_passes', label => 'Merge passes'},
	{name => 'Sort_scan',         label => 'Scan'},
    ],
};

#---------------------------------------------------------------------

$graphs{table_locks} = {
    config => {
	global_attrs => {
	    title  => 'Table locks',
	    vlabel => 'locks per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Table_locks_immediate', label => 'Table locks immed'},
	{name => 'Table_locks_waited',    label => 'Table locks waited'},
    ],
};

#---------------------------------------------------------------------

$graphs{tmp_tables} = {
    config => {
	global_attrs => {
	    title  => 'Temporary objects',
	    vlabel => 'Objects per ${graph_period}',
	},
	data_source_attrs => {
	    draw  => 'LINE2',
	},
    },
    data_sources => [
	{name => 'Created_tmp_disk_tables', label => 'Temp disk tables'},
	{name => 'Created_tmp_tables',      label => 'Temp tables'},
	{name => 'Created_tmp_files',       label => 'Temp files'},
    ],
};

#---------------------------------------------------------------------
#  Plugin Graphs
#  These are mysql plugins of type INFORMATION SCHEMA
#
#  These will be added to $graphs if available
#---------------------------------------------------------------------

my %graph_plugins = ();

$graph_plugins{query_response_time} = {
    count => {
        config => {
            global_attrs => {
                title  => 'Query Response Time Count',
                vlabel  => 'queries per ${graph_period}',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        # data_sources are populated by sub plugin_query_response_time
        data_sources => [
        ],
   },
   total => {
        config => {
            global_attrs => {
                title  => 'Query Response Time Total',
                vlabel  => 'query time (microseconds) per ${graph_period}',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        # data_sources are populated by sub plugin_query_response_time
        data_sources => [
        ],
   }
};

$graph_plugins{user_statistics} = {
    connections => {
        config => {
            global_attrs => {
                title  => 'User Connections',
                vlabel  => 'connections per ${graph_period}',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        cols => { 'total_connections' => {}, 'concurrent_connections' => {}, 'denied_connections' => {}, 'lost_connections'  => {}},
        data_sources => [
        ],
   },
   usertime => {
        config => {
            global_attrs => {
                title  => 'User Time',
                vlabel  => 'seconds',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        cols => { 'connected_time' => {}, 'busy_time' => {}, 'cpu_time' => {} },
        data_sources => [
        ],
   },
   bytes => {
        config => {
            global_attrs => {
                title  => 'User Bytes',
                vlabel  => 'bytes',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        cols => { 'bytes_received' => {}, 'bytes_sent' => {}, 'binlog_bytes_written' => {} },
        data_sources => [
        ],
   },
   rows => {
        config => {
            global_attrs => {
                title  => 'User Rows',
                vlabel  => 'rows',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        cols => { 'rows_read' => {}, 'rows_sent' => {}, 'rows_deleted' => {}, 'rows_inserted' => {}, 'rows_updated' => {} },
        data_sources => [
        ],
   },
   commands => {
        config => {
            global_attrs => {
                title  => 'Command breakdown by user',
                vlabel  => 'commands',
            },
            data_source_attrs => {
                draw  => 'LINE2',
                type => 'DERIVE',
            },
        },
        cols => { 'select_commands' => {}, 'update_commands' => {}, 'other_commands' => {}, 'commit_transactions' => {}, 'rollback_transactions' => {} },
        data_sources => [
        ],
   }

};
#---------------------------------------------------------------------
#  M A I N
#---------------------------------------------------------------------


#
# Global hash holding the data collected from mysql.
#
our $data; # Was 'my'. Changed to 'our' to facilitate testing.


sub main {
    my $graph = basename($0);
    $graph =~ s/^mysql[0-9]*_//g; # allow multiple instances
    my $command = $ARGV[0] || 'show';

    my %command_map = (
	'autoconf' => \&autoconf,
	'config'   => \&config,
	'show'     => \&show,
	'suggest'  => \&suggest,
    );

    die "Unknown command: $command"
	unless exists $command_map{$command};

    die "Missing dependency Cache::Cache"
	unless $has_cache || $command eq 'autoconf';

    die "Missing dependency DBI"
        unless $has_dbi || $command eq 'autoconf';

    die "Missing dependency Math::BigInt"
        unless $has_math_bigint || $command eq 'autoconf';

    return $command_map{$command}->($graph);
}


#---------------------------------------------------------------------
#  C O M M A N D   H A N D L E R S
#---------------------------------------------------------------------

# Each command handler should return an appropriate exit code


# http://munin-monitoring.org/wiki/ConcisePlugins#autoconf
sub autoconf {
    unless ($has_cache) {
	print "no (Missing dependency Cache::Cache)\n";
	return 0;
    }
    unless ($has_dbi) {
	print "no (Missing dependency DBI)\n";
	return 0;
    }
    unless ($has_math_bigint) {
	print "no (Missing dependency Math::BigInt)\n";
	return 0;
    }

    eval {
	db_connect();
    };
    if ($@) {
	my $err = $@;
	$err =~ s{\s at \s \S+ \s line .*}{}xms;
	print "no ($err)\n";
	return 0;
    }
    print "yes\n";
    return 0;
}


# http://munin-monitoring.org/wiki/ConcisePlugins#suggest
sub suggest {

    # What is the best way to decide which graphs is applicable to a
    # given system?
    #
    # Does the database use InnoDB? A zero count from:
    #
    #   SELECT COUNT(*)
    #     FROM tables
    #    WHERE table_type = 'base table'
    #      AND engine     = 'innodb'
    #
    # Does the database use binary logs? 'OFF' as the result from:
    #
    #   SHOW GLOBAL variables LIKE 'log_bin'
    #
    # Is the database setup as a slave? Empty result from:
    #
    #   SHOW SLAVE STATUS

    foreach my $graph (sort keys(%graphs)) {
        next if $graph =~ /innodb_/ && $data->{_innodb_disabled};
        next if $graph =~ /wsrep_/ && $data->{_galera_disabled};
        print "$graph\n";
    }

    return 0;
}


sub config {
    my $graph_name = shift;

    # In MySQL 5.1 (and probably erlier versions as well) status
    # variables are unique when looking at the last 19 characters.
    #
    #   SELECT RIGHT(variable_name, 19), COUNT(*)
    #     FROM information_schema.global_status
    #    GROUP BY RIGHT(variable_name, 19)
    #   HAVING COUNT(*) > 1;
    #
    #   Empty set (0.06 sec)
    #
    # There is one duplicate when looking at server variables
    #
    #   SELECT RIGHT(variable_name, 19), COUNT(*)
    #     FROM information_schema.global_variables
    #    GROUP BY RIGHT(variable_name, 19)
    #   HAVING COUNT(*) > 1;
    #
    #   +--------------------------+----------+
    #   | RIGHT(variable_name, 19) | COUNT(*) |
    #   +--------------------------+----------+
    #   | OW_PRIORITY_UPDATES      |        2 |
    #   +--------------------------+----------+
    #   1 row in set (0.05 sec)
    #
    #   show global variables like '%OW_PRIORITY_UPDATES';
    #
    #   +--------------------------+-------+
    #   | Variable_name            | Value |
    #   +--------------------------+-------+
    #   | low_priority_updates     | OFF   |
    #   | sql_low_priority_updates | OFF   |
    #   +--------------------------+-------+
    #   2 rows in set (0.00 sec)
    #
    # Not a problem since we don't graph these

    update_data();

    die 'Unknown graph ' . ($graph_name ? $graph_name : '')
	unless $graphs{$graph_name};

    my $graph = $graphs{$graph_name};

    my %conf = (%{$defaults{global_attrs}}, %{$graph->{config}{global_attrs}});
    while (my ($k, $v) = each %conf) {
	print "graph_$k $v\n";
    }
    print "graph_category mysql2\n";

    for my $ds (@{$graph->{data_sources}}) {
	my %ds_spec = (
	    %{$defaults{data_source_attrs}},
	    %{$graph->{config}{data_source_attrs}},
	    %$ds,
	);
	while (my ($k, $v) = each %ds_spec) {
            # 'name' is only used internally in this script, not understood by munin.
            printf("%s.%s %s\n", clean_fieldname($ds->{name}), $k, $v) unless ($k eq 'name');
	}
	print_thresholds(clean_fieldname($ds->{name}));
    }

    return 0;
}

sub show {
    my $graph_name = shift;

    update_data();

    die 'Unknown graph ' . ($graph_name ? $graph_name : '')
	unless $graphs{$graph_name};

    my $graph = $graphs{$graph_name};

    die "Can't show data for '$graph_name' because InnoDB is disabled."
	if $graph_name =~ /innodb_/ && $data->{_innodb_disabled};

    for my $ds (@{$graph->{data_sources}}) {
        my $value = exists $ds->{value}
            ? $ds->{value}($data)
                : $data->{$ds->{name}};

        printf "%s.value %s\n", clean_fieldname($ds->{name}), defined($value) ? $value : 'U';
    }

    return 0;
}



#---------------------------------------------------------------------
#  U T I L I T Y   S U B S
#---------------------------------------------------------------------


sub db_connect {
    my $dsn = "$config{dsn};mysql_connect_timeout=5";

    return DBI->connect($dsn, $config{user}, $config{password}, {
	RaiseError       => 1,
	PrintError       => 0,
	FetchHashKeyName => 'NAME_lc',
    });
}


sub update_data {
    $data = $shared_memory_cache->get('data');
    my $graphs_stored = $shared_memory_cache->get('graphs');
    %graphs = %{thaw($graphs_stored)} if $graphs_stored;
    return if $data;

    #warn "Need to update cache";

    $data = {};

    my $dbh = db_connect();

    # Set up defaults in case the server is not a slave
    $data->{relay_log_space} = 0;
    $data->{slave_running}   = 0;
    $data->{slave_stopped}   = 0;

    # Set up defaults in case binlog is not enabled
    $data->{ma_binlog_size} = 0;

    update_variables($dbh);
    update_plugins($dbh);
    update_innodb($dbh);
    update_master($dbh);
    update_slave($dbh);

    $shared_memory_cache->set('data', $data);
    $shared_memory_cache->set('graphs', nfreeze(\%graphs));
}


sub update_plugins {
    my ($dbh) = @_;

    my %plugin_map = (
	'query_response_time'         => \&plugin_query_response_time,
    );

    sub add_graphs {
      my ($f, $sec, $dbh, %g) = @_;
      if ($f->($dbh) == 0) {
        while (my ($k, $v) = each %g) {
          $graphs{$sec . '_' . $k} = $v;
        }
      }
    }

    my $sth = $dbh->prepare("SHOW PLUGINS");
    $sth->execute();
    while (my $row = $sth->fetchrow_hashref()) {
        next if $row->{'type'} ne 'INFORMATION SCHEMA';
        my $sec = lc $row->{'name'};
        next if not exists $plugin_map{$sec};
        add_graphs($plugin_map{$sec}, $sec, $dbh, %{$graph_plugins{$sec}});
    }
    $sth->finish();

    my %is_map = (
	'user_statistics'         => \&is_user_statistics,
    );

    $sth = $dbh->prepare("SHOW TABLES IN INFORMATION_SCHEMA");
    $sth->execute();
    while (my $row = $sth->fetchrow_hashref()) {
        my $sec = lc $row->{'tables_in_information_schema'};
        next if not exists $is_map{$sec};
        add_graphs($is_map{$sec}, $sec, $dbh, %{$graph_plugins{$sec}});
    }
    $sth->finish();
}

sub update_variables {
    my ($dbh) = @_;
    my @queries = (
	'SHOW GLOBAL STATUS',
	'SHOW GLOBAL VARIABLES',
    );

    my %variable_name_map = (
	table_cache => 'table_open_cache', # table_open_cache was
					   # previously known as
					   # table_cache in MySQL
					   # 5.1.2 and earlier.
    );

    for my $query (@queries) {
	$data->{$query} = {};

	my $sth = $dbh->prepare($query);
	$sth->execute();
	while (my $row = $sth->fetch) {
	    my $var = $variable_name_map{$row->[0]} || $row->[0];
	    $data->{$var} = $row->[1];
	}
	$sth->finish();
    }
}


sub update_innodb {
    my ($dbh) = @_;

    my $sth = $dbh->prepare('SHOW /*!50000 ENGINE*/ INNODB STATUS');
    eval {
	$sth->execute();
    };
    if ($@) {
	if ($@ =~ /Unknown (storage|table) engine 'INNODB'|Cannot call SHOW INNODB STATUS because skip-innodb is defined/i) {
	    $data->{_innodb_disabled} = 1;
	    return;
	}
	die $@;
    }
    my $row = $sth->fetchrow_hashref();
    my $status = $row->{'status'};
    $sth->finish();

    parse_innodb_status($status);
}


sub update_master {
    my ($dbh) = @_;

    my $sth = $dbh->prepare('SHOW MASTER LOGS');
    eval {
	$sth->execute();
    };
    if ($@) {
	# SHOW MASTER LOGS failed becuase binlog is not enabled
	return if $@ =~ /You are not using binary logging/;
	die $@;
    }

    while (my $row = $sth->fetch) {
	$data->{ma_binlog_size} += $row->[1];
    }

    $sth->finish();
}


sub update_slave {
    my ($dbh) = @_;

    my $sth = $dbh->prepare('SHOW SLAVE STATUS');
    $sth->execute();
    my $row = $sth->fetchrow_hashref();
    return unless $row;
    while (my ($k, $v) = each %$row) {
	$data->{$k} = $v;
    }
    $sth->finish();

    # undef when slave is stopped, or when MySQL fails to calculate
    # the lag (which happens depresingly often). (mk-heartbeat fixes
    # this problem.)
    $data->{seconds_behind_master} ||= 0;

    # Track these two fields so we can trigger warnings if the slave stops
    # running
    $data->{slave_sql_running} = ($data->{slave_sql_running} eq 'Yes')
	    ? 0 : 1;
    $data->{slave_io_running} = ($data->{slave_io_running} eq 'Yes')
	    ? 0 : 1;

}


#---------------------------------------------------------------------
#  Information SCHEMA tables represent data to be processed
#---------------------------------------------------------------------


sub plugin_query_response_time {
    my ($dbh) = @_;

    return 1 if not defined $data->{query_response_time_stats};
    return 1 if $data->{query_response_time_stats} eq 'OFF';

    my $sth = $dbh->prepare("SELECT * FROM INFORMATION_SCHEMA.QUERY_RESPONSE_TIME");
    $sth->execute();
    while (my $row = $sth->fetchrow_hashref()) {
        my $time = $row->{'time'};
        $data->{'query_response_time_count_' . $time} = $row->{'count'};
        push @{$graph_plugins{query_response_time}->{count}->{data_sources}}, {name => 'query_response_time_count_' . $time, label => $time };
        next if $row->{'total'} eq 'TOO LONG';
        $data->{'query_response_time_total_' . $time} = $row->{'total'} * 1e6;
        push @{$graph_plugins{query_response_time}->{total}->{data_sources}}, {name => 'query_response_time_total_' . $time, label => $time };
    }
    $sth->finish();

    return 0;
}

sub is_user_statistics {
    my ($dbh) = @_;

    return 1 if not defined $data->{userstat};
    return 1 if $data->{userstat} eq 'OFF';

    my $sth = $dbh->prepare("SELECT * FROM INFORMATION_SCHEMA.USER_STATISTICS");
    $sth->execute();
    while (my $row = $sth->fetchrow_hashref()) {
        my $user = $row->{'user'};
        my $var;
        while (my ($g, $v) = each %{$graph_plugins{user_statistics}}) {
          while (my ($userstat,$conf) = each %{$v->{cols}}) {
            $var = 'user_stats_' . $user . '_' . $userstat;
            $data->{$var} = int $row->{$userstat};
            my $ds = { %$conf };
            $ds->{name} = $var;
            $ds->{label} = $user . ' ' . $userstat;
            push @{$graph_plugins{user_statistics}->{$g}->{data_sources}}, $ds;
          }
        }
    }
    $sth->finish();
    return 0;
}

#
# In 'SHOW ENGINE INNODB STATUS' 64 bit integers are not formated as
# plain integers. They are either:
#
#   - split in two and needs to be shifted together,
#   - or hexadecimal
#
sub innodb_bigint {
    my ($x, $y) = @_;

    return defined $y
	? Math::BigInt->new($x)->blsft(32) + $y
	: Math::BigInt->new("0x$x");
}

#---------------------------------------------------------------------
#  P A R S E   'SHOW ENGINE INNODB STATUS'   O U T P U T
#---------------------------------------------------------------------


# A nice walk through
# http://www.mysqlperformanceblog.com/2006/07/17/show-innodb-status-walk-through/

# The parsing is split in one subrutine per section. Each subroutine
# should parse a block with the following structure
#
# block body ...
# more lines ....
# ----------

sub parse_innodb_status {
    local $_ = shift;

    # Add a dummy section to the end in case the innodb status output
    # has been truncated (Happens for status > 64K characters)
    $_ .= "\n----------\nDUMMY\n";

    my %section_map = (

	'BUFFER POOL AND MEMORY'      => \&parse_buffer_pool_and_memory,
	'INDIVIDUAL BUFFER POOL INFO' => \&skip,
	'FILE I/O'                    => \&parse_file_io,
	'INSERT BUFFER AND ADAPTIVE HASH INDEX'
	    => \&parse_insert_buffer_and_adaptive_hash_index,
	'LATEST DETECTED DEADLOCK'    => \&skip,
	'LATEST FOREIGN KEY ERROR'    => \&skip,
	'LOG'                         => \&parse_log,
	'ROW OPERATIONS'              => \&skip,
	'SEMAPHORES'                  => \&parse_semaphores,
	'TRANSACTIONS'                => \&parse_transactions,
	'BACKGROUND THREAD'           => \&skip,
    );

    skip_heading();
    for (;;) {
	m/\G(.*)\n/gc;
	my $sec = $1;

	last if $sec eq 'END OF INNODB MONITOR OUTPUT';
	if ($sec eq 'DUMMY') {
	    handle_incomplete_innodb_status();
	    last;
	}

	die "Unknown section: $1" unless exists $section_map{$sec};
	die "Parse error. Expected a section separator" unless m/\G-+\n/gc;

	$section_map{$sec}->();
    }
}


# This regular expression handles the different formating of 64-bit
# integers in different versions of the innodb engine. Either two
# decimal 32-bit integers seperated by a space, or a single
# hexadecimal 64-bit integer.
my $innodb_bigint_rx = qr{([[a-fA-F\d]+)(?: (\d+))?};


sub match_dashes { return m/\G-+\n(?!-)/gc; }


sub skip_line    { return m/\G.*\n/gc; }


sub skip_heading {
    # Heading is 6 lines
    for my $foo (1...6) {
	skip_line or die('Parse error');
    }
}


sub parse_section {
    my ($parser) = @_;

    #warn substr($_, pos(), 10);
    for (;;) {
	return if match_dashes();
	next if $parser->();
	skip_line();
    }
}


sub skip { parse_section(sub {}); }


sub parse_semaphores {
    parse_section(
	sub {
	    m/\GMutex spin waits (\d+), rounds (\d+), OS waits (\d+)\n/gc && do {
		$data->{ib_spin_waits}  = $1;
		$data->{ib_spin_rounds} = $2;
		$data->{ib_os_waits}    = $3;
		return 1;
	    };
	}
    );
}


sub parse_transactions {
    parse_section(
	sub {
	    m/\GTrx id counter $innodb_bigint_rx\n/gc && do {
		$data->{ib_tnx} = innodb_bigint($1, $2);
		return 1;
	    };
	    m/\GPurge done for trx's n:o < $innodb_bigint_rx undo n:o < $innodb_bigint_rx\n/gc && do {
		if (defined $3) {
		    # old format
		    $data->{ib_tnx_prg} = innodb_bigint($1, $2);
		    # FIX add to data? innodb_bigint($3, $4);
		}
		else {
		    # new format
		    $data->{ib_tnx_prg} = innodb_bigint($1);
		    # FIX add to data? innodb_bigint($2);
		}
		return 1;
	    };
	    m/\GHistory list length (\d+)\n/gc && do {
		$data->{ib_tnx_hist} = $1;
		return 1;
	    };
	}
    );

}


sub parse_file_io {
    parse_section(
	sub {
	    m/\GPending normal aio reads: (\d+), aio writes: (\d+),\n\s*ibuf aio reads: (\d+), log i\/o's: (\d+), sync i\/o's: (\d+)\n/gc && do {
		$data->{ib_iop_aioread}  = $1;
		$data->{ib_iop_aiowrite} = $2;
		$data->{ib_iop_ibuf_aio} = $3;
		$data->{ib_iop_log}      = $4;
		$data->{ib_iop_sync}     = $5;
		return 1;
	    };
	    m/\GPending flushes \(fsync\) log: (\d+); buffer pool: (\d+)\n/gc && do {
		$data->{ib_iop_flush_log}   = $1;
		$data->{ib_iop_flush_bpool} = $2;
		return 1;
	    };
	    m/\G(\d+) OS file reads, (\d+) OS file writes, (\d+) OS fsyncs\n/gc && do {
		$data->{ib_io_read}  = $1;
		$data->{ib_io_write} = $2;
		$data->{ib_io_fsync} = $3;
		return 1;
	    };
	}
    );
}


sub parse_insert_buffer_and_adaptive_hash_index {
    parse_section(
	sub {
      # MySQL < 5.5
      m/\G(\d+) inserts, (\d+) merged recs, (\d+) merges\n/gc && do {
        $data->{ib_ibuf_inserts}    = $1;
        $data->{ib_ibuf_merged_rec} = $2;
        $data->{ib_ibuf_merges}     = $3;
        return 1;
      };
      # MySQL >= 5.5
      m/\Gmerged operations:\n insert (\d+), delete mark \d+, delete \d+\ndiscarded operations:\n insert (\d+), delete mark \d+, delete \d+\n/gc && do {
        $data->{ib_ibuf_inserts} = $1;
        $data->{ib_ibuf_merged_rec} = $1 + $2;
        return 1;
      };
      m/\GIbuf: size (\d+), free list len (\d+), seg size (\d+),(?: (\d+) merges)?\n/gc && do {
        $data->{ib_ibuf_size}     = $1;
        $data->{ib_ibuf_free_len} = $2;
        $data->{ib_ibuf_seg_size} = $3;
        $data->{ib_ibuf_merges}   = $4 if defined $4; # MySQL >= 5.5
        return 1;
      };
	}
    );
}


sub parse_log {
    parse_section(
	sub {
	    m/\GLog sequence number $innodb_bigint_rx\n/gc && do {
		$data->{ib_log_written} = innodb_bigint($1, $2);
		return 1;
	    };
	    m/\GLog flushed up to\s+$innodb_bigint_rx\n/gc && do {
		$data->{ib_log_flush} = innodb_bigint($1, $2);
		return 1;
	    };
	    m/\G(\d+) log i\/o's done.*\n/gc && do {
		$data->{ib_io_log} = $1;
		return 1;
	    };
	}
    );
}


sub parse_buffer_pool_and_memory {
    parse_section(
	sub {
	    m/\GBuffer pool size\s+(\d+)\n/gc && do {
		$data->{ib_bpool_size} = $1;
		return 1;
	    };
	    m/\GFree buffers\s+(\d+)\n/gc && do {
		$data->{ib_bpool_free} = $1;
		return 1;
	    };
	    m/\GDatabase pages\s+(\d+)\n/gc && do {
		$data->{ib_bpool_dbpages} = $1;
		return 1;
	    };
	    m/\GModified db pages\s+(\d+)\n/gc && do {
		$data->{ib_bpool_modpages} = $1;
		return 1;
	    };
	    m/\GPages read (\d+), created (\d+), written (\d+)\n/gc && do {
		$data->{ib_bpool_read}    = $1;
		$data->{ib_bpool_created} = $2;
		$data->{ib_bpool_written} = $3;
		return 1;
	    };
	}
    );
}


sub handle_incomplete_innodb_status {

    warn "Output from SHOW ENGINE INNDOB STATUS was truncated. "
	. "This happens if the output of SEIS exceeds 64KB. "
	. "Several of the InnoDB graphs might be affected by this.";

    # FIX Is it possible to find some of the missing values from SHOW
    # STATUS?
}


exit main() unless caller;


1;
