The rabbitmqctl status command can be used to return the state of RabbitMQ. 

rabbitmqctl status

If RabbitMQ is running, something like this should be returned.

Status of node rabbit@server001 ...
Runtime

OS PID: 59844
OS: Linux
Uptime (seconds): 6779
RabbitMQ version: 3.8.3
Node name: rabbit@server001
Erlang configuration: Erlang/OTP 22 [erts-10.5.2] [source] [64-bit] [smp:6:6] [ds:6:6:10] [async-threads:96] [hipe]
Erlang processes: 15122 used, 1048576 limit
Scheduler run queue: 1
Cluster heartbeat timeout (net_ticktime): 60

Plugins

Enabled plugin file: /etc/rabbitmq/enabled_plugins
Enabled plugins:

 * rabbitmq_message_timestamp
 * rabbitmq_prometheus
 * rabbitmq_shovel_management
 * rabbitmq_management
 * rabbitmq_web_dispatch
 * rabbitmq_auth_backend_ldap
 * rabbitmq_management_agent
 * rabbitmq_shovel
 * amqp_client
 * cowboy
 * cowlib
 * amqp10_client
 * amqp10_common
 * prometheus

Data directory

Node data directory: /opt/rabbitmq/mnesia/rabbit@server001

Config files

 * /etc/rabbitmq/advanced.config
 * /etc/rabbitmq/rabbitmq.conf

Log file(s)

 * /usr/local/inet/logs/rabbitmq/rabbit.log
 * /var/log/rabbitmq/rabbit@server001_upgrade.log

Alarms

(none)

Memory

Calculation strategy: rss
Memory high watermark setting: 0.4 of available memory, computed to: 6.655 gb
allocated_unused: 0.1841 gb (23.48 %)
binary: 0.1191 gb (15.19 %)
other_proc: 0.1143 gb (14.58 %)
queue_procs: 0.1005 gb (12.81 %)
connection_other: 0.0609 gb (7.76 %)
other_ets: 0.0441 gb (5.62 %)
plugins: 0.038 gb (4.85 %)
code: 0.0267 gb (3.4 %)
mgmt_db: 0.0258 gb (3.28 %)
other_system: 0.0187 gb (2.39 %)
msg_index: 0.0175 gb (2.23 %)
connection_readers: 0.0108 gb (1.38 %)
mnesia: 0.0062 gb (0.79 %)
metrics: 0.0061 gb (0.78 %)
connection_channels: 0.0041 gb (0.52 %)
reserved_unallocated: 0.0038 gb (0.49 %)
connection_writers: 0.0017 gb (0.21 %)
atom: 0.0016 gb (0.2 %)
quorum_queue_procs: 0.0002 gb (0.02 %)
quorum_ets: 0.0001 gb (0.01 %)
queue_slave_procs: 0.0 gb (0.0 %)

File Descriptors

Total: 1185, limit: 32671
Sockets: 317, limit: 29401

Free Disk Space

Low free disk space watermark: 0.05 gb
Free disk space: 104.1952 gb

Totals

Connection count: 220
Queue count: 1018
Virtual host count: 195

Listeners

Interface: [::], port: 25672, protocol: clustering, purpose: inter-node and CLI tool communication
Interface: [::], port: 5671, protocol: amqp/ssl, purpose: AMQP 0-9-1 and AMQP 1.0 over TLS
Interface: [::], port: 15671, protocol: https, purpose: HTTP API over TLS (HTTPS)
Interface: [::], port: 15692, protocol: http/prometheus, purpose: Prometheus exporter API over HTTP

If RabbitMQ is not running, something like this should be returned.

Error: unable to perform an operation on node 'rabbit@server001'. Please see diagnostics information and suggestions below.

Most common reasons for this are:

 * Target node is unreachable (e.g. due to hostname resolution, TCP connection or firewall issues)
 * CLI tool fails to authenticate with the server (e.g. due to CLI tool's Erlang cookie not matching that of the server)
 * Target node is not running

In addition to the diagnostics info below:

 * See the CLI, clustering and networking guides on https://rabbitmq.com/documentation.html to learn more
 * Consult server logs on node rabbit@server001
 * If target node is configured to use long node names, don't forget to use --longnames with CLI tools

DIAGNOSTICS
===========

attempted to contact: [rabbit@server001]

rabbit@server001:
  * connected to epmd (port 4369) on server001
  * epmd reports: node 'rabbit' not running at all
                  no other nodes on server001
  * suggestion: start the node

Current node details:
 * node name: 'rabbitmqcli-86998-rabbit@server001'
 * effective user's home directory: /var/lib/rabbitmq
 * Erlang cookie hash: abc123