Types:

Permits access to the specified set of nodes.

Before the first call to allow/1, any node with the correct cookie can be connected. When allow/1 is called, a list of allowed nodes is established. Any access attempts made from (or to) nodes not in that list will be rejected.

Subsequent calls to allow/1 will add the specified nodes to the list of allowed nodes. It is not possible to remove nodes from the list.

Returns error if any element in Nodes is not an atom.

Types:

Establishes a connection to Node. Returns true if a connection was established or was already established or if Node is the local node itself. Returns false if the connection attempt failed, and ignored if the local node is not alive.

Types:

Returns currently used net tick time in seconds. For more information see the net_ticktime kernel(7) parameter.

Defined return values (Res):

Types:

Get one or more options for the distribution socket connected to Node.

If Node is a connected node the return value is the same as from inet:getopts(Sock, Options) where Sock is the distribution socket for Node.

Returns ignored if the local node is not alive or {error, noconnection} if Node is not connected.

Get the current state of the distribution for the local node.

Returns a map with (at least) the following key-value pairs:

Types:

The calling process subscribes or unsubscribes to node status change messages. A nodeup message is delivered to all subscribing processes when a new node is connected, and a nodedown message is delivered when a node is disconnected.

If Flag is true, a new subscription is started. If Flag is false, all previous subscriptions started with the same Options are stopped. Two option lists are considered the same if they contain the same set of options.

Delivery guarantees of nodeup/nodedown messages:

The format of the node status change messages depends on Options. If Options is the empty list or if net_kernel:monitor_nodes/1 is called, the format is as follows:

{nodeup, Node} | {nodedown, Node}


  Node = node()

When Options is the empty map or empty list, the caller will only subscribe for status change messages for visible nodes. That is, only nodes that appear in the result of erlang:nodes/0.

If Options equals anything other than the empty list, the format of the status change messages is as follows:

{nodeup, Node, Info} | {nodedown, Node, Info}


  Node = node()


  Info = #{Tag => Val} | [{Tag, Val}]

Info is either a map or a list of 2-tuples. Its content depends on Options. If Options is a map, Info will also be a map. If Options is a list, Info will also be a list.

When Options is a map, currently the following associations are allowed:

When Options is a list, currently ListOption can be one of the following:

Example:

(a@localhost)1> net_kernel:monitor_nodes(true, #{connection_id=>true, node_type=>all, nodedown_reason=>true}).
ok
(a@localhost)2> flush().
Shell got {nodeup,b@localhost,


                  #{connection_id => 3067552,node_type => visible}}
Shell got {nodeup,c@localhost,


                  #{connection_id => 13892107,node_type => hidden}}
Shell got {nodedown,b@localhost,


                    #{connection_id => 3067552,node_type => visible,


                      nodedown_reason => connection_closed}}
Shell got {nodedown,c@localhost,


                    #{connection_id => 13892107,node_type => hidden,


                      nodedown_reason => net_tick_timeout}}
Shell got {nodeup,b@localhost,


                  #{connection_id => 3067553,node_type => visible}}
ok
(a@localhost)3> 


        

Types:

Sets net_ticktime (see kernel(7)) to NetTicktime seconds. TransitionPeriod defaults to 60.

Some definitions:

If NetTicktime < PreviousNetTicktime, the net_ticktime change is done at the end of the transition period; otherwise at the beginning. During the transition period, net_kernel ensures that there is outgoing traffic on all connections at least every MTTI millisecond.

Returns one of the following:

Types:

Set one or more options for distribution sockets. Argument Node can be either one node name or the atom new to affect the distribution sockets of all future connected nodes.

The return value is the same as from inet:setopts/2 or {error, noconnection} if Node is not a connected node or new.

If Node is new the Options will then also be added to kernel configuration parameters inet_dist_listen_options and inet_dist_connect_options.

Returns ignored if the local node is not alive.

Types:

Turns a non-distributed node into a distributed node by starting net_kernel and other necessary processes.

If Name is set to undefined the distribution will be started to request a dynamic node name from the first node it connects to. See Dynamic Node Name. Setting Name to undefined implies options dist_listen => false and hidden => true.

Currently supported options:

Types:

Turns a non-distributed node into a distributed node by starting net_kernel and other necessary processes.

Options list can only be exactly one of the following lists (order is imporant):

Types:

Turns a distributed node into a non-distributed node. For other nodes in the network, this is the same as the node going down. Only possible when the net kernel was started using start/2, otherwise {error, not_allowed} is returned. Returns {error, not_found} if the local node is not alive.