Configuration

RabbitMQ comes with default built-in settings which will most likely be sufficient for running your RabbitMQ server effectively. If it runs fine, then you probably don't need any configuration at all.

If you have other constraints, RabbitMQ provides two general ways to customise the server:

environment variables
define ports, file locations and names (taken from the shell, or set in the rabbitmq-env.conf file)
a configuration file
defines server component settings for permissions, limits and clusters, and also plugin settings.

Customise RabbitMQ Environment

Unix (general)

On Unix-based systems (including Linux, MacOSX) you can create/edit rabbitmq-env.conf to define environment variables. Its location is not configurable (unlike rabbitmq.config).

Use the standard environment variable names (but drop the RABBITMQ_ prefix) e.g.

#example rabbitmq-env.conf file entries
#Rename the node
NODENAME=bunny
#Config file location and new filename bunnies.config
CONFIG_FILE=/etc/rabbitmq/testdir/bunnies
More info on using rabbitmq-env.conf

RabbitMQ Environment Variables

RabbitMQ environment variable names have the prefix RABBITMQ_. A typical variable called RABBITMQ_var_name is set as follows:

  • a shell environment variable called RABBITMQ_var_name is used if this is defined;
  • otherwise, a variable called var_name is used if this is set in the rabbitmq-env.conf file;
  • otherwise, a system-specified default value is used.

In this way, variables set in the shell environment take priority over variables set in rabbitmq-env.conf, which in turn over-ride RabbitMQ built-in defaults.

It is unlikely you will need to set any of these environment variables. If you have non-standard requirements, then RabbitMQ environment variables include, but are not limited to:

NameDefaultDescription
RABBITMQ_NODE_IP_ADDRESS the empty string - meaning bind to all network interfaces. Change this if you only want to bind to one network interface.
RABBITMQ_NODE_PORT 5672
RABBITMQ_NODENAME
  • Unix*: rabbit@$HOSTNAME
  • Windows: rabbit@%COMPUTERNAME%
The node name should be unique per erlang-node-and-machine combination. To run multiple nodes, see the clustering guide.
RABBITMQ_SERVICENAME Windows Service: RabbitMQ The name of the installed service. This will appear in services.msc.
RABBITMQ_CONSOLE_LOG Windows Service: Set this variable to new or reuse to redirect console output from the server to a file named %RABBITMQ_SERVICENAME%.debug in the default RABBITMQ_BASE directory.
  • If not set, console output from the server will be discarded (default).
  • new A new file will be created each time the service starts.
  • reuse The file will be overwritten each time the service starts.
RABBITMQ_CTL_ERL_ARGS None Parameters for the erl command used when invoking rabbitmqctl. This should be overridden for debugging purposes only.
RABBITMQ_SERVER_ERL_ARGS
  • Unix*: "+K true +A30 +P 1048576 -kernel inet_default_connect_options [{nodelay,true}]"
  • Windows: Not configurable
Standard parameters for the erl command used when invoking the RabbitMQ Server. This should be overridden for debugging purposes only.
RABBITMQ_SERVER_START_ARGS None Extra parameters for the erl command used when invoking the RabbitMQ Server. This will not override RABBITMQ_SERVER_ERL_ARGS.
* Unix, Linux, MacOSX

In addition, there are several environment variables which tell RabbitMQ where to locate its database, log files, plugins, configuration etc.

Other variables upon which RabbitMQ depends are:

NameDefaultDescription
HOSTNAME
  • Unix, Linux: `env hostname`
  • MacOSX: `env hostname -s`
The name of the current machine
COMPUTERNAME Windows: localhost The name of the current machine
ERLANG_SERVICE_MANAGER_PATH Windows Service: %ERLANG_HOME%\erts-x.x.x\bin This path is the location of erlsrv.exe, the Erlang service wrapper script.

Configuration File

The rabbitmq.config File

The configuration file rabbitmq.config allows the RabbitMQ core application, Erlang services and RabbitMQ plugins to be configured. It is a standard Erlang configuration file, documented on the Erlang Config Man Page.

An example configuration file follows:

  [
    {mnesia, [{dump_log_write_threshold, 1000}]},
    {rabbit, [{tcp_listeners, [5673]}]}
  ].

This example will alter the dump_log_write_threshold for mnesia (increasing from the default of 100), and alter the port RabbitMQ listens on from 5672 to 5673.

This configuration file is not the same as rabbitmq-env.conf, which can be used to set environment variables on non-windows systems. A future release of RabbitMQ will unify the two configuration mechanisms.

Variables Configurable in rabbitmq.config

Many users of RabbitMQ never need to change any of these values, and some are fairly obscure. However, for completeness they are all listed here.

Key Default value Documentation
tcp_listeners [5672] List of ports on which to listen for AMQP connections (without SSL). Can contain integers (meaning "listen on all interfaces") or tuples such as {"127.0.0.1", 5672} to listen on a single interface.
ssl_listeners [] As above, for SSL connections.
ssl_options [] SSL configuration. See the SSL documentation.
vm_memory_high_watermark 0.4 Memory threshold at which the flow control is triggered. See the memory-based flow control documentation.
disk_free_limit 1000000000 Disk free space limit of the partition on which RabbitMQ is storing data. When available disk space falls below this limit, flow control is triggered. The value may be set relative to the total amount of RAM (e.g. {mem_relative, 1.0}). The value may also be set to an integer number of bytes. By default free disk space must exceed 1GB. See the memory-based flow control documentation.
log_levels [{connection, info}] Controls the granularity of logging. The value is a list of log event category and log level pairs.

The level can be one of 'none' (no events are logged), 'error' (only errors are logged), 'warning' (only errors and warning are logged), or 'info' (errors, warnings and informational messages are logged).

At present there is just one category defined - 'connection', for all events relating to network connections. Other, currently uncategorised, events are always logged.

frame_max 131072 Maximum permissible size of a frame (in bytes) to negotiate with clients. Setting to 0 means "unlimited" but will trigger a bug in some QPid clients. Setting a larger value may improve throughput; setting a smaller value may improve latency.
default_vhost <<"/">> Virtual host to create when RabbitMQ creates a new database from scratch. The exchange amq.rabbitmq.log will exist in this virtual host.
default_user <<"guest">> User name to create when RabbitMQ creates a new database from scratch.
default_pass <<"guest">> Password for the default user.
default_user_tags [administrator] Tags for the default user.
default_permissions [<<".*">>, <<".*">>, <<".*">>] Permissions to assign to the default user when creating it.
cluster_nodes [] Set this to cause clustering to happen automatically.
server_properties [] List of key-value pairs to announce to clients on connection.
collect_statistics none Statistics collection mode. Primarily relevant for the management plugin. Options are:
  • none (do not emit statistics events)
  • coarse (emit per-queue / per-channel / per-connection statistics)
  • fine (also emit per-message statistics)
You probably don't want to change this yourself.
collect_statistics_interval 5000 Statistics collection interval in milliseconds. Primarily relevant for the management plugin.
auth_mechanisms ['PLAIN', 'AMQPLAIN'] SASL authentication mechanisms to offer to clients.
auth_backends [rabbit_auth_backend_internal] List of authentication databases to use. Other databases than rabbit_auth_backend_internal are available through plugins.
delegate_count 16 Number of delegate processes to use for intra-cluster communication. On a machine which has a very large number of cores and is also part of a cluster, you may wish to increase this value.
trace_vhosts [] Used internally by the tracer. You shouldn't change this.
tcp_listen_options
[binary, {packet,        raw},
         {reuseaddr,     true},
         {backlog,       128},
         {nodelay,       true},
         {exit_on_close, false}]
Default socket options. You probably don't want to change this.
hipe_compile false Set to true to precompile parts of RabbitMQ with the High Performance Erlang compiler. This will increase the message rate that the server can handle, while also increasing startup time.

You might see 20-50% better performance at the cost of approximately 1 minute delay at startup. These figures are highly workload- and hardware-dependent.

HiPE support may not be compiled into your Erlang installation. If it is not, enabling this option will just cause a warning message to be displayed and startup will proceed as normal. For example, Debian / Ubuntu users will need to install the erlang-base-hipe package.

HiPE is not available at all on some platforms, notably including Windows.

This option should be considered experimental. If your Erlang VM segfaults, disable this option again.

msg_store_index_module rabbit_msg_store_ets_index Implementation module for queue indexing. You probably don't want to change this.
backing_queue_module rabbit_variable_queue Implementation module for queue contents. You probably don't want to change this.
msg_store_file_size_limit 16777216 Tunable value for the persister. You almost certainly should not change this.
queue_index_max_journal_entries 262144 Tunable value for the persister. You almost certainly should not change this.

In addition, many plugins can have sections in the configuration file, with names of the form rabbitmq_plugin. See the plugins page for more information.