Provided by:
mosquitto_0.12-1_i386 
NAME
mosquitto.conf - the configuration file for mosquitto
SYNOPSIS
mosquitto.conf
DESCRIPTION
mosquitto.conf is the configuration file for mosquitto. This file can
reside anywhere as long as mosquitto can read it. By default, mosquitto
does not need a configuration file and will use the default values
listed below. See mosquitto(8) for information on how to load a
configuration file.
FILE FORMAT
All lines with a # as the very first character are treated as a
comment.
Configuration lines start with a variable name. The variable value is
separated from the name by a single space.
VARIABLES
acl_file
Set the path to an access control list file. If defined, the
contents of the file are used to control client access to topics
on the broker.
If this parameter is defined then only the topics listed will
have access. Topic access is added with lines of the format:
topic [read|write] <topic>
The access type is controlled using "read" or "write". This
parameter is optional - if not given then the access is
read/write. <topic> can contain the + or # wildcards as in
subscriptions.
The first set of topics are applied to anonymous clients,
assuming allow_anonymous is true. User specific topic ACLs are
added after a user line as follows:
user <username>
The username referred to here is the same as in password_file.
It is not the clientid.
Reloaded on reload signal. The currently loaded ACLs will be
freed and reloaded. Existing subscriptions will be affected
after the reload.
allow_anonymous
Boolean value that determines whether clients that connect
without providing a username are allowed to connect. If set to
false then a password file should be created (see the
password_file option) to control authenticated client access.
Defaults to true.
Reloaded on reload signal.
autosave_interval
The number of seconds that mosquitto will wait between each time
it saves the in-memory database to disk. If set to 0, the in-
memory database will only be saved when mosquitto exits or when
receiving the SIGUSR1 signal. Note that this setting only has an
effect if persistence is enabled. Defaults to 1800 seconds (30
minutes).
Reloaded on reload signal.
bind_address
Listen for incoming network connections on the specified IP
address/hostname only. This is useful to restrict access to
certain network interfaces. To restrict access to mosquitto to
the local host only, use "bind_address localhost". This only
applies to the default listener. Use the listener variable to
control other listeners.
Not reloaded on reload signal.
clientid_prefixes
If defined, only clients that have a clientid with a prefix that
matches clientid_prefixes will be allowed to connect to the
broker. For example, setting "secure-" here would mean a client
"secure-client" could connect but another with clientid "mqtt"
couldn't. By default, all client ids are valid.
Reloaded on reload signal. Note that currently connected clients
will be unaffected by any changes.
listener
Listen for incoming network connection on the specified port. A
second optional argument allows the listener to be bound to a
specific ip address/hostname. If this variable is used and
neither bind_address nor port are used then the default listener
will not be started. This option may be specified multiple
times. See also the mount_point option.
Not reloaded on reload signal.
log_dest
Send log messages to a particular destination. Possible
destinations are: stdout stderr syslog topic. stdout and stderr
log to the console on the named output. syslog uses the
userspace syslog facility which usually ends up in
/var/log/messages or similar and topic logs to the broker topic
'$SYS/broker/log/<severity>', where severity is one of D, E, W,
N, I which are debug, error, warning, notice and information.
Use "log_dest none" if you wish to disable logging. Defaults to
stderr. This option may be specified multiple times.
Reloaded on reload signal.
log_type
Choose types of messages to log. Possible types are: debug,
error, warning, notice, information, none. Defaults to error,
warning, notice and information. This option may be specified
multiple times. Note that the debug type (used for decoding
incoming network packets) is never logged in syslog or topics.
Reloaded on reload signal.
max_connections
Limit the total number of clients connected for the current
listener. Set to -1 to have "unlimited" connections. Note that
other limits may be imposed that are outside the control of
mosquitto. See e.g. limits.conf(5).
Not reloaded on reload signal.
max_inflight_messages
The maximum number of QoS 1 or 2 messages that can be in the
process of being transmitted simultaneously. This includes
messages currently going through handshakes and messages that
are being retried. Defaults to 20. Set to 0 for no maximum. If
set to 1, this will guarantee in-order delivery of messages.
Reloaded on reload signal.
max_queued_messages
The maximum number of QoS 1 or 2 messages to hold in the queue
above those messages that are currently in flight. Defaults to
100. Set to 0 for no maximum (not recommended).
Reloaded on reload signal.
mount_point
This option is used with the listener option to isolate groups
of clients. When a client connects to a listener which uses this
option, the string argument is attached to the start of all
topics for this client. This prefix is removed when any messages
are sent to the client. This means a client connected to a
listener with mount point example can only see messages that are
published in the topic hierarchy example and above.
Not reloaded on reload signal.
password_file
Set the path to a password file. If defined, the contents of the
file are used to control client access to the broker. Each line
should be in the format "username:password", where the colon and
password are optional but recommended. If allow_anonymous is set
to false, only users defined in this file will be able to
connect. Setting allow_anonymous to true when password_file is
defined is valid and could be used with acl_file to have e.g.
read only guest/anonymous accounts and defined users that can
publish.
Reloaded on reload signal. The currently loaded username and
password data will be freed and reloaded. Clients that are
already connected will not be affected.
persistence
Can be true or false. If true, connection, subscription and
message data will be written to the disk in mosquitto.db at the
location dictated by persistence_location. When mosquitto is
restarted, it will reload the information stored in
mosquitto.db. The data will be written to disk when mosquitto
closes and also at periodic intervals as defined by
autosave_interval. Writing of the persistence database may also
be forced by sending mosquitto the SIGUSR1 signal. If false, the
data will be stored in memory only. Defaults to false.
Reloaded on reload signal.
persistence_file
The filename to use for the persistent database. Defaults to
mosquitto.db.
Reloaded on reload signal.
persistence_location
The path where the persistence database should be stored. Must
end in a trailing slash. If not given, then the current
directory is used.
Reloaded on reload signal.
pid_file
Write a pid file to the file specified. If not given (the
default), no pid file will be written. If the pid file cannot be
written, mosquitto will exit. This option only has an effect is
mosquitto is run in daemon mode.
If mosquitto is being automatically started by an init script it
will usually be required to write a pid file. This should then
be configured as /var/run/mosquitto.pid
Not reloaded on reload signal.
port Set the network port for the default listener to listen on.
Defaults to 1883.
Not reloaded on reload signal.
retained_persistence
This is a synonym of the persistence option.
Reloaded on reload signal.
retry_interval
The integer number of seconds after a QoS=1 or QoS=2 message has
been sent that mosquitto will wait before retrying when no
response is received. If unset, defaults to 20 seconds.
Reloaded on reload signal.
store_clean_interval
The integer number of seconds between the internal message store
being cleaned of messages that are no longer referenced. Lower
values will result in lower memory usage but more processor
time, higher values will have the opposite effect. Setting a
value of 0 means the unreferenced messages will be disposed of
as quickly as possible. Defaults to 10 seconds.
Reloaded on reload signal.
sys_interval
The integer number of seconds between updates of the $SYS
subscription hierarchy, which provides status information about
the broker. If unset, defaults to 10 seconds.
Reloaded on reload signal.
user When run as root, change to this user and its primary group on
startup. If mosquitto is unable to change to this user and
group, it will exit with an error. The user specified must have
read/write access to the persistence database if it is to be
written. If run as a non-root user, this setting has no effect.
Defaults to mosquitto.
This setting has no effect on Windows and so you should run
mosquitto as the user you wish it to run as.
Not reloaded on reload signal.
CONFIGURING BRIDGES
Multiple bridges (connections to other brokers) can be configured using
the following variables.
Bridges cannot currently be reloaded on reload signal.
address address[:port], addresses address[:port]
Specify the address and optionally the port of the bridge to
connect to. This must be given for each bridge connection. If
the port is not specified, the default of 1883 is used.
Unlike rsmb, it is not currently possible to specify multiple
addresses for a single bridge connection here. This is true even
if the name "addresses" is used.
cleansession [ true | false ]
Set the clean session option for this bridge. Setting to false
(the default), means that all subscriptions on the remote broker
are kept in case of the network connection dropping. If set to
true, all subscriptions and messages on the remote broker will
be cleaned up if the connection drops. Note that setting to true
may cause a large amount of retained messages to be sent each
time the bridge reconnects.
clientid id
Set the client id for this bridge connection. If not defined,
this defaults to 'name.hostname', where name is the connection
name and hostname is the hostname of this computer.
connection name
This variable marks the start of a new bridge connection. It is
also used to give the bridge a name which is used as the client
id on the remote broker.
keepalive_interval seconds
Set the number of seconds after which the bridge should send a
ping if no other traffic has occurred. Defaults to 60. A
minimum value of 5 seconds isallowed.
password value
Configure a password for the bridge. This is used for
authentication purposes when connecting to a broker that support
MQTT v3.1 and requires a username and/or password to connect.
This option is only valid if a username is also supplied.
topic pattern [ out | in | both ]
Define a topic pattern to be shared between the two brokers. Any
topics matching the pattern (which may include wildcards) are
shared. The second parameter defines the direction that the
messages will be shared in, so it is possible to import messages
from a remote broker using "in", export messages to a remote
broker using "out" or share messages in both directions. If this
parameter is not defined, the default of "out" is used.
This option can be specified multiple times per bridge.
Care must be taken to ensure that loops are not created with
this option. If you are experiencing high CPU load from a
broker, it is possible that you have a loop where each broker is
forever forwarding each other the same messages.
username name
Configure a username for the bridge. This is used for
authentication purposes when connecting to a broker that support
MQTT v3.1 and requires a username and/or password to connect.
See also the password option.
EXTERNAL SECURITY CHECKS
The following options are available when external security checks have
been compiled in. Unless you have done this yourself it is unlikely to
exist.
db_host hostname
Database host name.
Reloaded on reload signal.
db_port port
Database port.
Reloaded on reload signal.
db_name name
Database name.
Reloaded on reload signal.
db_username username
Database username.
Reloaded on reload signal.
db_password password
Database password.
Reloaded on reload signal.
FILES
mosquitto.conf
BUGS
mosquitto bug information can be found at
http://launchpad.net/mosquitto
SEE ALSO
mosquitto(8) mqtt(7) limits.conf(5)
AUTHOR
Roger Light <roger@atchoo.org>
25 July 2011 mosquitto.conf(5)