MMM

This manual is for MMM version 2.

1. Overview

MMM (Master-Master Replication Manager for MySQL) is a set of flexible scripts to perform monitoring/failover and management of MySQL Master-Master replication configurations (with only one node writable at any time). The toolset also has the ability to read balance standard master/slave configurations with any number of slaves, so you can use it to move virtual IP addresses around a group of servers depending on whether they are behind in replication. In addition to that, it also has scripts for data backups, resynchronization between nodes etc.

The main functionality is provided through the following three scripts:

mmm_mond

monitoring daemon which does all monitoring work and makes all decisions about roles moving and so on.

mmm_agentd

agent daemon which runs on each MySQL server and provides monitoring node with simple set of remote services.

mmm_control

simple script dedicated to management of the mmm_mond processes by commands.

2. Typical use-cases

Typical use cases of MMM will be described in the following two sections.

2.1 Two node setup

In two node master-master setup, MMM uses five IPs: single permanent IP for each node that is never changed, 2 reader IPs (read-only) and 1 writer IP (updates). Last three IPs are migrating between the nodes depending on node availability.

Normally (no replication failures, no replication delay etc) active master has 2 IPs (reader and writer), standby master - 1 IP (reader). In case of a failure, both - writer and reader roles migrate to the working node.

2.2 Two masters + one/many slaves

3. Requirements

For an MMM setup with n MySQL servers, you'll need

n + 1 hosts

One host for each MySQL server; one host for the MMM monitor.

2 * (n + 1) IPs

One IP for each host (see above); one IP for the writer role; n IPs for one reader role per host.

monitor user

A MySQL user with privileges REPLICATION CLIENT for MMM monitor.

agent user

A MySQL user with privileges SUPER, REPLICATION CLIENT, PROCESS for MMM agent.

replication user

A MySQL user with privileges REPLICATION SLAVE used for replication.

tools user

A MySQL user with privileges SUPER, REPLICATION CLIENT, RELOAD for MMM tools.

3.1 Requirements - monitoring host

• perl with ithreads support
• fping (if you want to run mmm_mond as non-root user)
• Perl modules:
  • - Algorithm::Diff
  • - Class:Singleton
  • - DBI and DBD::mysql
  • - File::Basename
  • - File::stat
  • - File::Temp
  • - Log::Dispatch
  • - Log::Log4perl
  • - Mail::Send
  • - Net::Ping
  • - Proc::Daemon
  • - Thread::Queue
  • - Time::HiRes

3.2 Requirements - nodes

One should set read-only=1 in the configuration of all MySQL servers, MMM will change that to read-only=0 on the host with the active_master_role.

• perl
• iproute
• send_arp (solaris)
• Perl modules:
  • - Algorithm::Diff
  • - DBI and DBD::mysql
  • - File::Basename
  • - File::stat
  • - Log::Dispatch
  • - Log::Log4perl
  • - Mail::Send
  • - Net::ARP (linux)
  • - Proc::Daemon
  • - Time::HiRes

3.3 Additional requirements for MMM tools

If you want to use the MMM tools (mmm_backup, mmm_restore, mmm_clone) you have to use LVM for the partition on which your MySQL databases and logs reside. Note: You'll need free physical extends for the snapshots undo space (see Estimating Undo Space needed for LVM Snapshot).

You'll also need the following perl modules:

• Path::Class
• Data::Dumper

4. mmm_agentd - the agent

TODO short description

5. mmm_mond - the monitor

5.1 States

• Only hosts with state ONLINE may have roles. When a host switches from ONLINE to any other state, all roles will be removed from it.
• A host that was in state REPLICATION_DELAY or REPLICATION_FAIL will be switched back to ONLINE if everything is OK again, unless it is flapping (see Flapping).
• A host that was in state HARD_OFFLINE will be switched to AWAITING_RECOVERY if everything is OK again. If its downtime was shorter than 60 seconds and it wasn't rebooted or auto_set_online is > 0 it will be switched back to ONLINE automatically, unless it is flapping (see Flapping again).
• Replication backlog or failure on the active master isn't considered to be a problem, so the active master will never be in state REPLICATION_DELAY or REPLICATION_FAIL.
• Replication backlog or failure will be ignored on hosts whos peers got ONLINE less than 60 seconds ago (That's the default value of master-connect-retry).
• If both checks rep_backlog and rep_threads fail, the state will change to REPLICATION_FAIL.

5.2 Roles

There are two types of roles:

exclusive roles

Exclusive roles may only have one ip and are assigned to one host at a time. You may specify a preferred host, to which the role will always be moved, if it's online. Note: You can't move roles which are assigned to the preferred host, because they would be moved back to it immediately.

balanced roles

Balanced roles may have multiple ips. The ips will be balanced between the hosts, so that no host has two roles more than another host.

TODO describe active_master_role allow writes change master of all hosts with mode=slave to this host

5.3 Status file

information about host state and roles ‘status_path’

5.4 Checks

mmm_mond performs four different checks on each host to determine if it is OK. These checks are:

5.5 Network check

mmm_mond has the ability to detect a non-functioning network connection. It regularly pings all ping_ips defined in the config. If at least one ip is reachable, the network is considered to be working.

Without working network connection mmm_mond will...

• ... ignore failed checks.
• ... not change the state of hosts.
• ... not send anything to agents.

If the network connection doesn't work during startup, mmm_mond will delay startup until it's available again.

5.6 Flapping

mmm_mond supports the detection of hosts that are "flapping". Flapping occurs if a host which is ONLINE changes its state to HARD_OFFLINE / REPLICATION_FAIL / REPLICATION_DELAY too often and each time gets switched back to ONLINE (because of auto_set_online or because it has been down for less than 60 seconds). This may lead to roles getting switched between hosts very often.

To prevent this mmm_mond has a built in flap-detection which can be tuned in the configuration file. If a host goes down for more than flap_count times within flap_duration seconds it is considered as flapping and will not be set ONLINE automatically. It will stay in state AWAITING_RECOVERY until it gets set online (with mmm_control set_online host).

If auto_set_online is > 0, flapping hosts will automatically be set to ONLINE after flap_duration seconds.

5.7 Modes

5.7.1 Active mode

The monitor will remove roles from failed hosts and assign them to other hosts automatically.

5.7.2 Manual mode

The monitor will only distribute balanced roles across the hosts, but will not remove roles from failed hosts automatically. You can remove roles from failed hosts manually with move_role.

5.7.3 Wait mode

Like MANUAL mode, but mode will be changed into ACTIVE mode when both master hosts are ONLINE or after wait_for_other_master seconds have elapsed.

5.7.4 Passive mode

In passive mode the monitor doesn't change roles, update the status file nor send anything to agents. In passive mode you can modify roles (unclean) with set_ip - the changes won't be applied until the monitor is switched to ACTIVE or MANUAL mode with set_active or set_manual. Passive mode will be entered if conflicting roles are detected during startup. You should then analyze the situation, fix the role information (if needed) and switch into ACTIVE or MANUAL mode. It also can be entered manually with set_passive.

5.8 Startup

• Initial network check
• If network is down startup will be delayed until it's reachable again.
• Initial host checks
• reads status information from ...
  • - status file
  • - agents (agent info)
  • - hosts (system info)

  and tries to figure out the cluster status.

5.9 Role transition

5.9.1 Standard role

• IP is removed from old host
• IP is configured on new host
• New host sends arp packets to inform other hosts that it now has the IP

5.9.2 Active master role

• Writer role is removed from old master:
  1. MySQL is made read_only
  2. Active connections are removed
  3. IP is removed
• Slaves are informed. They:
  1. Try to catch up with the old master as far as possible
  2. Change master to the new master
• Writer role is added to the new master:
  1. MySQL is made writable
  2. IP is configured

5.10 Kill host functionality

If a host goes down and the agent on it can't be reached, the monitor executes a "kill host"-binary if present. You have to provide a custom binary for this which takes the hostname as first argument and the state of check ping (1 - ok; 0 - not ok) as second argument. This binary could for example:

• SSH to the failed host and use iptables to close mysql from the world by dropping all connections to port 3306.
• Tell a UPS to poweroff the failed host.
• ...

The default location for this binary is ‘bin_path/monitor/kill_host’. This may be changed via the variable kill_host_bin in the monitor section of the configuration.

6. mmm_control - controlling the monitor

The monitor daemon may be controlled with the help of mmm_control. If you have multiple clusters, you should always specify the name of the cluster you want to work with (i.e. to check C1 status, use "mmm_control @C1 show"). Otherwise - if you have only one MMM cluster, it can be used without cluster name.

6.1 help

Show help message.

6.2 ping

Ping the monitor deamon to check if it's still alive.

# mmm_control ping
OK: Pinged successfully!

When the monitor is down:

# mmm_control ping
ERROR: Can't connect to monitor daemon!

6.3 show

Show the current cluster status. See States for an explanation of the different node states.

# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.51)
  db2(192.168.0.32) master/AWAITING_RECOVERY. Roles:
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.52), reader(192.168.0.53)

6.4 checks [host|all [check|all]]

Show information about the specified/all check(s) for the specified/all host(s).

# mmm_control checks
mmm-master1  ping         [last change: 2010/02/11 12:43:16]  OK
mmm-master1  mysql        [last change: 2010/02/11 12:43:16]  OK
mmm-master1  rep_threads  [last change: 2010/02/11 12:43:16]  OK
mmm-master1  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null
mmm-master2  ping         [last change: 2010/02/11 12:43:16]  OK
mmm-master2  mysql        [last change: 2010/02/11 12:43:16]  OK
mmm-master2  rep_threads  [last change: 2010/02/11 12:43:16]  OK
mmm-master2  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null
# mmm_control checks mmm-master1
mmm-master1  ping         [last change: 2010/02/11 12:43:16]  OK
mmm-master1  mysql        [last change: 2010/02/11 12:43:16]  OK
mmm-master1  rep_threads  [last change: 2010/02/11 12:43:16]  OK
mmm-master1  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null
# mmm_control checks mmm-master1 rep_backlog
mmm-master1  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null
# mmm_control checks all rep_backlog
mmm-master1  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null 
mmm-master2  rep_backlog  [last change: 2010/02/11 12:43:16]  OK: Backlog is null

6.5 set_online host

set_online is used to recover a node from a failure when it's state is AWAITING_RECOVERY or ADMIN_OFFLINE. In the following example, the host db2 was rebooted. Here's the cluster status:

# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.51)
  db2(192.168.0.32) master/AWAITING_RECOVERY. Roles:
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.52), reader(192.168.0.53)

All roles have been moved to hosts db1 and db3 as db2 has failed. Now that it's recovered, we should set it online:

# mmm_control set_online db2
OK: State of 'db2' changed to ONLINE. Now you can wait some time and check its new roles!
# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.51)
  db2(192.168.0.32) master/ONLINE. Roles: reader(192.168.0.52)
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.53)

6.6 set_offline host

set_offline is used to bring a node down manually for maintenance. This will remove all roles and stop replication.

# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.51)
  db2(192.168.0.32) master/ONLINE. Roles: reader(192.168.0.52)
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.53)
# mmm_control set_offline db1
OK: State of 'db1' changed to ADMIN_OFFLINE. Now you can wait some time and check all roles!
mon:~# mmm_control show
  db1(192.168.0.31) master/ADMIN_OFFLINE. Roles:
  db2(192.168.0.32) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.52)
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.51), reader(192.168.0.53)

set_online is used to bring the node back online again. See set_online host.

6.7 mode

Print current mode. In the following example, the monitor is running in ACTIVE mode:

# mmm_control mode
ACTIVE

Here the monitor is in PASSIVE mode:

# mmm_control mode
PASSIVE

See Modes.

6.8 set_active

Switch the monitor into ACTIVE mode:

# mmm_control set_active
OK: Switched into active mode.

See Modes.

6.9 set_manual

Switch the monitor into MANUAL mode:

# mmm_control set_manual
OK: Switched into manual mode.

See Modes.

6.10 set_passive

Switch the monitor into PASSIVE mode:

# mmm_control set_passive
OK: Switched into passive mode.

See Modes.

6.11 move_role role host

Used to move an exclusive role between the cluster nodes. This command is not available in PASSIVE mode. Lets assume the following situation:

# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: reader(192.168.0.51)
  db2(192.168.0.32) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.52)
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.53)

We use move_role to move the role writer to host db1:

# mmm_control move_role writer db1
OK: Role 'writer' has been moved from 'db2' to 'db1'. Now you can wait some time and check new roles info!
# mmm_control show
  db1(192.168.0.31) master/ONLINE. Roles: writer(192.168.0.50), reader(192.168.0.51)
  db2(192.168.0.32) master/ONLINE. Roles: reader(192.168.0.52)
  db3(192.168.0.33) slave/ONLINE. Roles: reader(192.168.0.53)

6.12 move_role --force role host

Can be used to move the active_master_role to a host with state REPLICATION_FAIL or REPLICATION_DELAY. Use this with caution! This command is not available in PASSIVE mode.

6.13 set_ip ip host

set_ip can be used to manipulate the roles in PASSIVE mode. The changes won't be applied until the monitor is switched into ACTIVE or manual mode via set_active or set_manual.

7. Configuration

7.1 Config files

Config files may resist in ‘/etc’, ‘/etc/mmm’ or ‘/etc/mysql-mmm’. ‘/etc/mysql-mmm’ should be preferred.

7.2 Configuration syntax

7.2.1 Comments

Lines which begin with the hash character # are considered comments, and are ignored. Comments may not be included on a line after a configuration directive. White space occuring before comments are ignored.

# This is a comment
debug	1 # this is no comment

7.2.2 Variables

asdsadasd

debug   0

7.2.3 Specifying multiple values

For some variables you may specify multiple values seperated by a comma:

ips     192.168.0.51, 192.168.0.52, 192.168.0.53

7.2.4 Sections

The configuration is divided into two kinds of sections: unique and named.

7.2.4.1 Unique sections

Unique sections ... TODO

<monitor>
    ip     127.0.0.1
</monitor>

It is also possible to define empty unique sections:

<socket/>

7.2.4.2 Named sections

Named sections ... TODO

<host db1>
    ip     192.168.0.31
</host>

You may also define empty named sections:

<check mysql/>

7.2.4.3 Default sections

Values assigned in sections named default will be used as default values for all other sections of this type.

# Default mode of all hosts is 'slave'
<host default>
    mode	slave
</host>

7.2.5 Includes

It is possible to split up the configuration into several files and include them via include.

include	common.conf

7.3 Configuration variables

7.3.1 Global variables

• this

  Description:	name of this host
  Default value:	-
  Used by:	agent, tools

• debug

  Description:	Enable debug mode
  Allowed values:	true/yes/1/on false/no/0/off
  Default value:	0
  Used by:	agent, monitor

• active_master_role

  Description:	name of the role for which identifies the active master
  Default value:	-
  Used by:	agent, monitor

• max_kill_retries

  Description:	Maximum number of retries when killing threads to prevent further writes during the removal of the active_master_role.
  Default value:	10
  Used by:	agent

• default_copy_method

  Description:	name of the default copy method
  Default value:	-
  Used by:	tools

• clone_dirs

  Description:	path(s) containing mysql data/logs (relative to mount point of logical volume)
  Default value:	-
  Used by:	tools

7.3.2 monitor section

The monitor section is required by mmm_mond and mmm_control.

• ip

  Description:	IP on which mmm_mond listens
  Default value:	-
  Used by:	control, monitor

• port

  Description:	Port on which mmm_mond listens
  Default value:	9988
  Used by:	control, monitor

• pid_path

  Description:	Location of pid-file
  Default value:	-
  Used by:	monitor

• bin_path

  Description:	Path to directory containing MMM binaries
  Default value:	-
  Used by:	monitor

• status_path

  Description:	Location of of status file
  Default value:	-
  Used by:	monitor

• ping_interval

  Description:	Break between network checks
  Default value:	1
  Used by:	monitor

• ping_ips

  Description:	IPs used for network checks
  Default value:	-
  Used by:	monitor

• flap_duration

  Description:	Duration in seconds for flap detection. See flap_count
  Default value:	3600
  Used by:	monitor

• flap_count

  Description:	Maximum number of downtimes within flap_duration seconds after which a host is considered to be flapping.
  Default value:	3
  Used by:	monitor

• auto_set_online

  Description:	How many seconds to wait before switching node status from AWAITING_RECOVERY to ONLINE. 0 = disabled.
  Default value:	0
  Used by:	monitor

• kill_host_bin

  Description:	Binary used to kill hosts if roles couldn't be removed because the agent was not reachable. You have to provide a custom binary for this which takes the hostname as first argument and the state of check ping (1 - ok; 0 - not ok) as second argument.
  Default value:	bin_path/monitor/kill_host
  Used by:	monitor

• careful_startup

  Description:	Startup carefully i.e. switch into passive mode when writer role is configured on multiple hosts.
  Allowed values:	true/yes/1/on false/no/0/off
  Default value:	0
  Used by:	monitor

• mode

  Description:	Default mode of monitor.
  Allowed values:	active manual wait passive
  Default value:	active
  Used by:	monitor

• wait_for_other_master

  Description:	How many seconds to wait for other master to become ONLINE before switching from mode WAIT to mode ACTIVE. 0 = infinite.
  Default value:	120
  Used by:	monitor

7.3.3 host sections

• ip

  Description:	IP of host
  Default value:	-
  Used by:	agent, monitor, tools

• mode

  Description:	Mode of host. Either master or slave.
  Default value:	-
  Used by:	agent, monitor

• peer

  Description:	Name of peer host (if mode is master)
  Default value:	-
  Used by:	agent, monitor

• pid_path

  Description:	Location of pid-file
  Default value:	-
  Used by:	agent

• bin_path

  Description:	Path to directory containing MMM binaries
  Default value:	-
  Used by:	agent

• agent_port

  Description:	Port on which mmm_agentd listens
  Default value:	9989
  Used by:	agent, monitor

• cluster_interface

  Description:	network interface on which the IPs of the roles should be configured
  Default value:	-
  Used by:	agent

• mysql_port

  Description:	Port on which mysqld is listening
  Default value:	3306
  Used by:	agent, monitor, tools

• mysql_pidfile

  Description:	location of mysql pid-file
  Default value:	/var/run/mysqld/mysqld.pid
  Used by:	tools

• mysql_rcscript

  Description:	location of mysql rc-script
  Default value:	/etc/init.d/mysql
  Used by:	tools

• mysql_cnf

  Description:	location of my.cnf
  Default value:	/etc/my.cnf
  Used by:	tools

• agent_user

  Description:	mysql user for MMM Agent
  Default value:	-
  Used by:	agent

• agent_password

  Description:	mysql password for MMM Agent
  Default value:	-
  Used by:	agent

• monitor_user

  Description:	mysql user for MMM Monitor
  Default value:	-
  Used by:	monitor

• monitor_password

  Description:	mysql password for MMM Monitor
  Default value:	-
  Used by:	monitor

• replication_user

  Description:	mysql user used for replication
  Default value:	-
  Used by:	agent, tools

• replication_password

  Description:	mysql password used for replication
  Default value:	-
  Used by:	agent, tools

• ssh_user

  Description:	SSH user for MMM Tools
  Default value:	-
  Used by:	tools

• ssh_port

  Description:	SSH port for MMM Tools
  Default value:	22
  Used by:	tools

• ssh_parameters

  Description:	additional SSH parameters for MMM Tools
  Default value:	-
  Used by:	tools

• tools_user

  Description:	mysql user for MMM Tools
  Default value:	-
  Used by:	tools

• tools_password

  Description:	mysql password for MMM Tools
  Default value:	-
  Used by:	tools

• backup_dir

  Description:	Target directory for backups
  Default value:	-
  Used by:	tools

• restore_dir

  Description:	Directory where backups should be restored to
  Default value:	-
  Used by:	tools

• lvm_bin_lvcreate

  Description:	Path to lvcreate binary
  Default value:	lvcreate
  Used by:	tools

• lvm_bin_lvremove

  Description:	Path to lvremove binary
  Default value:	lvremove
  Used by:	tools

• lvm_snapshot_size

  Description:	Size of LVM snapshot
  Default value:	-
  Used by:	tools

• lvm_logical_volume

  Description:	Logical volume where mysql data and logs reside
  Default value:	-
  Used by:	tools

• lvm_volume_group

  Description:	Volume group of logical volume with mysql data and logs
  Default value:	-
  Used by:	tools

• lvm_mount_dir

  Description:	Mount point for LVM snapshot
  Default value:	-
  Used by:	tools

• lvm_mount_opts

  Description:	Mount options used when mounting LVM snapshot
  Default value:	-
  Used by:	tools

7.3.4 role sections

This section defines what roles are in the cluster and which IPs will be used for each role. Since roles are moved among servers each server needs an IP (for the monitor to talk to it) and each role needs an IP.

• mode

  Description:	Mode of role. Either balanced or exclusive (see see section Roles).
  Default value:	-
  Used by:	monitor

• hosts

  Description:	Hosts which may take over the role
  Default value:	-
  Used by:	monitor

• ips

  Description:	One or multiple IPs associated with the role
  Default value:	-
  Used by:	agent, monitor

• prefer

  Description:	The preferred host for this role. Only allowed for exclusive roles.
  Default value:	-
  Used by:	monitor

7.3.5 check sections

• check_period

  Description:	Perform check every 5 seconds
  Default value:	5
  Used by:	monitor

• trap_period

  Description:	Check is considered as failed if it doesn't succeed for at least trap_period seconds.
  Default value:	10
  Used by:	monitor

• timeout

  Description:	Check times out after timeout seconds
  Default value:	2
  Used by:	monitor

• restart_after

  Description:	Restart checker process after restart_after checks
  Default value:	10000
  Used by:	monitor

• max_backlog

  Description:	Maximum backlog for check rep_backlog.
  Default value:	60
  Used by:	monitor

7.3.6 socket section

• type

  Description:	Socket type to use. Either plain or ssl
  Default value:	-
  Used by:	agent, control, monitor

• cert_file

  Description:	location of SSL certificate (if type is ssl)
  Default value:	-
  Used by:	agent, control, monitor

• key_file

  Description:	location of RSA private key (if type is ssl)
  Default value:	-
  Used by:	agent, control, monitor

• ca_file

  Description:	location of file containing certificate(s) of the reputable certificate authorities (if type is ssl)
  Default value:	-
  Used by:	agent, monitor

7.3.7 copy_method sections

• backup_command

  Description:	Command used for creation of backup
  Default value:	-
  Used by:	tools

• restore_command

  Description:	Command used for restoring backup
  Default value:	-
  Used by:	tools

• incremental_command

  Description:	Command used for showing available increments
  Default value:	-
  Used by:	tools

• incremental

  Description:	Indicates whether the copy method supports incremental backups
  Default value:	0
  Used by:	tools

• single_run

  Description:	Indicates whether the copy method is able to copy all dirs in one single run
  Default value:	0
  Used by:	tools

• true_copy

  Description:	Indicates whether the copy method creates a 1:1 copy of the data
  Default value:	0
  Used by:	tools

8. Logging

8.1 Logging config files

MMM uses Log4perl for logging, so the logging abilities are very flexible. If the default logging configuration doesn't fit your needs you can create a config file which may resist in ‘/etc’, ‘/etc/mmm’ or ‘/etc/mysql-mmm’. ‘/etc/mysql-mmm’ should be preferred.

The name of the file depends on the program you want to create it for:

8.2 Log4perl sample configuration

Here is the default logging configuration:

log4perl.logger = INFO, LogFile
log4perl.appender.LogFile = Log::Log4perl::Appender::File
log4perl.appender.LogFile.Threshold = INFO 
log4perl.appender.LogFile.filename = /var/log/mysql-mmm.htmlprogam.info
log4perl.appender.LogFile.recreate = 1
log4perl.appender.LogFile.layout = PatternLayout
log4perl.appender.LogFile.layout.ConversionPattern = %d %5p %m%n

In addition to that, if debug mode is enabled:

log4perl.logger = DEBUG, ScreenLog, LogFile
log4perl.appender.ScreenLog = Log::Log4perl::Appender::Screen
log4perl.appender.ScreenLog.stderr = 0
log4perl.appender.ScreenLog.layout = PatternLayout
log4perl.appender.ScreenLog.layout.ConversionPattern = %d %5p %m%n

It is also possible to log into multiple files (separated by severity) or let MMM send you mails (this was the default logging configuration in versions below 2.1.1):

log4perl.logger = INFO, FileInfo, FileWarn, FileError, FileFatal, MailFatal
log4perl.appender.FileInfo = Log::Log4perl::Appender::File
log4perl.appender.FileInfo.Threshold = INFO 
log4perl.appender.FileInfo.filename = /var/log/mysql-mmm.htmlprogam.info
log4perl.appender.FileInfo.recreate = 1
log4perl.appender.FileInfo.layout = PatternLayout
log4perl.appender.FileInfo.layout.ConversionPattern = %d %5p %m%n
log4perl.appender.FileWarn = Log::Log4perl::Appender::File
log4perl.appender.FileWarn.Threshold = WARN 
log4perl.appender.FileWarn.filename = /var/log/mysql-mmm.htmlprogam.warn
log4perl.appender.FileWarn.recreate  = 1
log4perl.appender.FileWarn.layout = PatternLayout
log4perl.appender.FileWarn.layout.ConversionPattern = %d %5p %m%n
log4perl.appender.FileError = Log::Log4perl::Appender::File
log4perl.appender.FileError.Threshold = ERROR 
log4perl.appender.FileError.filename = /var/log/mysql-mmm.htmlprogam.error
log4perl.appender.FileError.recreate = 1
log4perl.appender.FileError.layout = PatternLayout
log4perl.appender.FileError.layout.ConversionPattern = %d %5p %m%n
log4perl.appender.FileFatal = Log::Log4perl::Appender::File
log4perl.appender.FileFatal.Threshold = FATAL 
log4perl.appender.FileFatal.filename = /var/log/mysql-mmm.htmlprogam.fatal
log4perl.appender.FileFatal.recreate = 1
log4perl.appender.FileFatal.layout = PatternLayout
log4perl.appender.FileFatal.layout.ConversionPattern = %d %5p %m%n
log4perl.appender.MailFatal = Log::Dispatch::Email::MailSend
log4perl.appender.MailFatal.Threshold = FATAL 
log4perl.appender.MailFatal.to = root
log4perl.appender.MailFatal.buffered = 0
log4perl.appender.MailFatal.subject = FATAL error in progam
log4perl.appender.MailFatal.layout = PatternLayout
log4perl.appender.MailFatal.layout.ConversionPattern = %d %m%n

Index

Table of Contents

About This Document

This document was generated on May, 7 2010 using texi2html 1.78.

The buttons in the navigation panels have the following meaning:

where the Example assumes that the current position is at Subsubsection One-Two-Three of a document of the following structure:

• 1. Section One
  • 1.1 Subsection One-One
    • ...
  • 1.2 Subsection One-Two
    • 1.2.1 Subsubsection One-Two-One
    • 1.2.2 Subsubsection One-Two-Two
    • 1.2.3 Subsubsection One-Two-Three     <== Current Position
    • 1.2.4 Subsubsection One-Two-Four
  • 1.3 Subsection One-Three
    • ...
  • 1.4 Subsection One-Four

This document was generated on May, 7 2010 using texi2html 1.78.