Live reconfiguration
Managing VerneMQ live config values.
You can dynamically re-configure most of VerneMQ's settings on a running node by using the vmq-admin set command.
The following config values can be handled dynamically:
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allow_anonymous
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topic_alias_max_broker
3
receive_max_broker
4
vmq_acl.acl_file
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graphite_host
6
vmq_acl.acl_reload_interval
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graphite_enabled
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queue_type
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suppress_lwt_on_session_takeover
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max_message_size
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vmq_passwd.password_file
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graphite_port
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max_client_id_size
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upgrade_outgoing_qos
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max_message_rate
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graphite_interval
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allow_multiple_sessions
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systree_enabled
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max_last_will_delay
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retry_interval
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receive_max_client
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max_offline_messages
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max_online_messages
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max_inflight_messages
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allow_register_during_netsplit
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vmq_passwd.password_reload_interval
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topic_alias_max_client
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systree_interval
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allow_publish_during_netsplit
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coordinate_registrations
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remote_enqueue_timeout
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persistent_client_expiration
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allow_unsubscribe_during_netsplit
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graphite_include_labels
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shared_subscription_policy
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queue_deliver_mode
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allow_subscribe_during_netsplit
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Settings dynamically configured with the vmq-admin set command will be reset by vernemq.conf upon broker restart.

Setting a value for the local node

Let's change the max_client_id_size as an example. (We might have noticed that some clients can't login because their client ID is too long, but we don't want to restart the broker for that). Note that you can also set multiple values with the same command.
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vmq-admin set max_client_id_size=45
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Setting a value for an arbitrary cluster node

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vmq-admin set max_client_id_size=45 [email protected]
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Setting a value for all cluster nodes

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vmq-admin set max_client_id_size=45 --all
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Show current VerneMQ config values

For the local node

You can show one or multiple values in a simple table:
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vmq-admin show max_client_id_size retry_interval
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+----------------------+------------------+--------------+
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| node |max_client_id_size|retry_interval|
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+----------------------+------------------+--------------+
4
|[email protected]| 28 | 20 |
5
+----------------------+------------------+--------------+
6
7
`
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For an arbitrary node

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vmq-admin show max_client_id_size retry_interval --node [email protected]
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For all cluster nodes

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vmq-admin show max_client_id_size retry_interval --all
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+----------------------+------------------+--------------+
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| node |max_client_id_size|retry_interval|
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+----------------------+------------------+--------------+
4
|[email protected]| 33 | 20 |
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|[email protected]| 33 | 20 |
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|[email protected]| 33 | 20 |
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|[email protected]| 33 | 20 |
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|[email protected]| 28 | 20 |
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+----------------------+------------------+--------------+
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Last modified 2mo ago