.TH net_kernel 3erl "kernel 8.5.4.3" "Ericsson AB" "Erlang Module Definition"
.SH NAME
net_kernel \- Erlang networking kernel.
.SH DESCRIPTION
.LP
The net kernel is a system process, registered as \fInet_kernel\fR\&, which must be operational for distributed Erlang to work\&. The purpose of this process is to implement parts of the BIFs \fIspawn/4\fR\& and \fIspawn_link/4\fR\&, and to provide monitoring of the network\&.
.LP
An Erlang node is started using command-line flag \fI-name\fR\& or \fI-sname\fR\&:
.LP
.nf

$ erl -sname foobar
.fi
.LP
It is also possible to call \fInet_kernel:start(foobar, #{})\fR\& directly from the normal Erlang shell prompt:
.LP
.nf

1> net_kernel:start(foobar, #{name_domain => shortnames})\&.
{ok,<0.64.0>}
(foobar@gringotts)2>
.fi
.LP
If the node is started with command-line flag \fI-sname\fR\&, the node name is \fIfoobar@Host\fR\&, where \fIHost\fR\& is the short name of the host (not the fully qualified domain name)\&. If started with flag \fI-name\fR\&, the node name is \fIfoobar@Host\fR\&, where \fIHost\fR\& is the fully qualified domain name\&. For more information, see \fIerl\fR\&\&.
.LP
Normally, connections are established automatically when another node is referenced\&. This functionality can be disabled by setting Kernel configuration parameter \fIdist_auto_connect\fR\& to \fInever\fR\&, see \fIkernel(7)\fR\&\&. In this case, connections must be established explicitly by calling \fIconnect_node/1\fR\&\&.
.LP
Which nodes that are allowed to communicate with each other is handled by the magic cookie system, see section Distributed Erlang in the Erlang Reference Manual\&.
.LP

.RS -4
.B
Warning:
.RE
Starting a distributed node without also specifying \fI-proto_dist inet_tls\fR\& will expose the node to attacks that may give the attacker complete access to the node and in extension the cluster\&. When using un-secure distributed nodes, make sure that the network is configured to keep potential attackers out\&. See the  Using SSL for Erlang Distribution User\&'s Guide for details on how to setup a secure distributed node\&.

.SH EXPORTS
.LP
.nf

.B
allow(Nodes) -> ok | error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Nodes = [node()]
.br
.RE
.RE
.RS
.LP
Permits access to the specified set of nodes\&.
.LP
Before the first call to \fIallow/1\fR\&, any node with the correct cookie can be connected\&. When \fIallow/1\fR\& is called, a list of allowed nodes is established\&. Any access attempts made from (or to) nodes not in that list will be rejected\&.
.LP
Subsequent calls to \fIallow/1\fR\& will add the specified nodes to the list of allowed nodes\&. It is not possible to remove nodes from the list\&.
.LP
Returns \fIerror\fR\& if any element in \fINodes\fR\& is not an atom\&.
.RE

.LP
.nf

.B
connect_node(Node) -> boolean() | ignored
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Node = node()
.br
.RE
.RE
.RS
.LP
Establishes a connection to \fINode\fR\&\&. Returns \fItrue\fR\& if a connection was established or was already established or if \fINode\fR\& is the local node itself\&. Returns \fIfalse\fR\& if the connection attempt failed, and \fIignored\fR\& if the local node is not alive\&.
.RE

.LP
.nf

.B
get_net_ticktime() -> Res
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Res = NetTicktime | {ongoing_change_to, NetTicktime} | ignored
.br
NetTicktime = integer() >= 1
.br
.RE
.RE
.RS
.LP
Returns currently used net tick time in seconds\&. For more information see the \fInet_ticktime\fR\& \fIkernel(7)\fR\& parameter\&.
.LP
Defined return values (\fIRes\fR\&):
.RS 2
.TP 2
.B
\fINetTicktime\fR\&:
\fInet_ticktime\fR\& is \fINetTicktime\fR\& seconds\&.
.TP 2
.B
\fI{ongoing_change_to, NetTicktime}\fR\&:
\fInet_kernel\fR\& is currently changing \fInet_ticktime\fR\& to \fINetTicktime\fR\& seconds\&.
.TP 2
.B
\fIignored\fR\&:
The local node is not alive\&.
.RE
.RE

.LP
.nf

.B
getopts(Node, Options) ->
.B
           {ok, OptionValues} | {error, Reason} | ignored
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Node = node()
.br
Options = [inet:socket_getopt()]
.br
OptionValues = [inet:socket_setopt()]
.br
Reason = inet:posix() | noconnection
.br
.RE
.RE
.RS
.LP
Get one or more options for the distribution socket connected to \fINode\fR\&\&.
.LP
If \fINode\fR\& is a connected node the return value is the same as from \fIinet:getopts(Sock, Options)\fR\& where \fISock\fR\& is the distribution socket for \fINode\fR\&\&.
.LP
Returns \fIignored\fR\& if the local node is not alive or \fI{error, noconnection}\fR\& if \fINode\fR\& is not connected\&.
.RE

.LP
.nf

.B
get_state() ->
.B
             #{started => no | static | dynamic,
.B
               name => atom(),
.B
               name_type => static | dynamic,
.B
               name_domain => shortnames | longnames}
.br
.fi
.br
.RS
.LP
Get the current state of the distribution for the local node\&.
.LP
Returns a map with (at least) the following key-value pairs:
.RS 2
.TP 2
.B
\fIstarted => Started\fR\&:
Valid values for \fIStarted\fR\&:
.RS 2
.TP 2
.B
\fIno\fR\&:
The distribution is not started\&. In this state none of the other keys below are present in the map\&.
.TP 2
.B
\fIstatic\fR\&:
The distribution was started with command line arguments \fI-name\fR\& or \fI-sname\fR\&\&.
.TP 2
.B
\fIdynamic\fR\&:
The distribution was started with \fInet_kernel:start/1\fR\& and can be stopped with \fInet_kernel:stop/0\fR\&\&.
.RE
.TP 2
.B
\fIname => Name\fR\&:
The name of the node\&. Same as returned by \fIerlang:node/0\fR\& except when \fIname_type\fR\& is \fIdynamic\fR\& in which case \fIName\fR\& may be \fIundefined\fR\& (instead of \fInonode@nohost\fR\&)\&.
.TP 2
.B
\fIname_type => NameType\fR\&:
Valid values for \fINameType\fR\&:
.RS 2
.TP 2
.B
\fIstatic\fR\&:
The node has a static node name set by the node itself\&.
.TP 2
.B
\fIdynamic\fR\&:
The distribution was started in  dynamic node name mode, and will get its node name assigned from the first node it connects to\&. If key \fIname\fR\& has value \fIundefined\fR\& that has not happened yet\&.
.RE
.TP 2
.B
\fIname_domain => NameDomain\fR\&:
Valid values for \fINameDomain\fR\&:
.RS 2
.TP 2
.B
\fIshortnames\fR\&:
The distribution was started to use node names with a short host portion (not fully qualified)\&.
.TP 2
.B
\fIlongnames\fR\&:
The distribution was started to use node names with a long fully qualified host portion\&.
.RE
.RE
.RE

.LP
.nf

.B
monitor_nodes(Flag) -> ok | Error
.br
.fi
.br
.nf

.B
monitor_nodes(Flag, Options) -> ok | Error
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Flag = boolean()
.br
Options = OptionsList | OptionsMap
.br
OptionsList = [ListOption]
.br
ListOption = 
.br
    connection_id | {node_type, NodeType} | nodedown_reason
.br
OptionsMap = 
.br
    #{connection_id => boolean(),
.br
      node_type => NodeType,
.br
      nodedown_reason => boolean()}
.br
NodeType = visible | hidden | all
.br
Error = error | {error, term()}
.br
.RE
.RE
.RS
.LP
The calling process subscribes or unsubscribes to node status change messages\&. A \fInodeup\fR\& message is delivered to all subscribing processes when a new node is connected, and a \fInodedown\fR\& message is delivered when a node is disconnected\&.
.LP
If \fIFlag\fR\& is \fItrue\fR\&, a new subscription is started\&. If \fIFlag\fR\& is \fIfalse\fR\&, all previous subscriptions started with the same \fIOptions\fR\& are stopped\&. Two option lists are considered the same if they contain the same set of options\&.
.LP
Delivery guarantees of \fInodeup\fR\&/\fInodedown\fR\& messages:
.RS 2
.TP 2
*
\fInodeup\fR\& messages are delivered before delivery of any signals from the remote node through the newly established connection\&.
.LP
.TP 2
*
\fInodedown\fR\& messages are delivered after all the signals from the remote node over the connection have been delivered\&.
.LP
.TP 2
*
\fInodeup\fR\& messages are delivered after the corresponding node appears in results from \fIerlang:nodes()\fR\&\&.
.LP
.TP 2
*
\fInodedown\fR\& messages are delivered after the corresponding node has disappeared in results from \fIerlang:nodes()\fR\&\&.
.LP
.TP 2
*
As of OTP 23\&.0, a \fInodedown\fR\& message for a connection being taken down will be delivered before a \fInodeup\fR\& message due to a new connection to the same node\&. Prior to OTP 23\&.0, this was not guaranteed to be the case\&.
.LP
.RE

.LP
The format of the node status change messages depends on \fIOptions\fR\&\&. If \fIOptions\fR\& is the empty list or if \fInet_kernel:monitor_nodes/1\fR\& is called, the format is as follows:
.LP
.nf

{nodeup, Node} | {nodedown, Node}
  Node = node()
.fi
.LP
When \fIOptions\fR\& 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 \fIerlang:nodes/0\fR\&\&.
.LP
If \fIOptions\fR\& equals anything other than the empty list, the format of the status change messages is as follows:
.LP
.nf

{nodeup, Node, Info} | {nodedown, Node, Info}
  Node = node()
  Info = #{Tag => Val} | [{Tag, Val}]
.fi
.LP
\fIInfo\fR\& is either a map or a list of 2-tuples\&. Its content depends on \fIOptions\fR\&\&. If \fIOptions\fR\& is a map, \fIInfo\fR\& will also be a map\&. If \fIOptions\fR\& is a list, \fIInfo\fR\& will also be a list\&.
.LP
When \fIOptions\fR\& is a map, currently the following associations are allowed:
.RS 2
.TP 2
.B
\fIconnection_id => boolean()\fR\&:
If the value of the association equals \fItrue\fR\&, a \fIconnection_id => ConnectionId\fR\& association will be included in the \fIInfo\fR\& map where \fIConnectionId\fR\& is the connection identifier of the connection coming up or going down\&. For more info about this connection identifier see the documentation of erlang:nodes/2\&.
.TP 2
.B
\fInode_type => NodeType\fR\&:
Valid values for \fINodeType\fR\&:
.RS 2
.TP 2
.B
\fIvisible\fR\&:
Subscribe to node status change messages for visible nodes only\&. The association \fInode_type => visible\fR\& will be included in the \fIInfo\fR\& map\&.
.TP 2
.B
\fIhidden\fR\&:
Subscribe to node status change messages for hidden nodes only\&. The association \fInode_type => hidden\fR\& will be included in the \fIInfo\fR\& map\&.
.TP 2
.B
\fIall\fR\&:
Subscribe to node status change messages for both visible and hidden nodes\&. The association \fInode_type => visible | hidden\fR\& will be included in the \fIInfo\fR\& map\&.
.RE
.RS 2
.LP
If no \fInode_type => NodeType\fR\& association is included in the \fIOptions\fR\& map, the caller will subscribe for status change messages for visible nodes only, but \fIno\fR\&  \fInode_type => visible\fR\& association will be included in the \fIInfo\fR\& map\&.
.RE

.TP 2
.B
\fInodedown_reason => boolean()\fR\&:
If the value of the association equals \fItrue\fR\&, a \fInodedown_reason => Reason\fR\& association will be included in the \fIInfo\fR\& map for \fInodedown\fR\& messages\&.
.RS 2
.LP
\fIReason\fR\& can, depending on which distribution module or process that is used, be any term, but for the standard TCP distribution module it is one of the following:
.RE

.RS 2
.TP 2
.B
\fIconnection_setup_failed\fR\&:
The connection setup failed (after \fInodeup\fR\& messages were sent)\&.
.TP 2
.B
\fIno_network\fR\&:
No network is available\&.
.TP 2
.B
\fInet_kernel_terminated\fR\&:
The \fInet_kernel\fR\& process terminated\&.
.TP 2
.B
\fIshutdown\fR\&:
Unspecified connection shutdown\&.
.TP 2
.B
\fIconnection_closed\fR\&:
The connection was closed\&.
.TP 2
.B
\fIdisconnect\fR\&:
The connection was disconnected (forced from the current node)\&.
.TP 2
.B
\fInet_tick_timeout\fR\&:
Net tick time-out\&.
.TP 2
.B
\fIsend_net_tick_failed\fR\&:
Failed to send net tick over the connection\&.
.TP 2
.B
\fIget_status_failed\fR\&:
Status information retrieval from the \fIPort\fR\& holding the connection failed\&.
.RE
.RE
.LP
When \fIOptions\fR\& is a list, currently \fIListOption\fR\& can be one of the following:
.RS 2
.TP 2
.B
\fIconnection_id\fR\&:
A \fI{connection_id, ConnectionId}\fR\& tuple will be included in \fIInfo\fR\& where \fIConnectionId\fR\& is the connection identifier of the connection coming up or going down\&. For more info about this connection identifier see the documentation of erlang:nodes/2\&.
.TP 2
.B
\fI{node_type, NodeType}\fR\&:
Valid values for \fINodeType\fR\&:
.RS 2
.TP 2
.B
\fIvisible\fR\&:
Subscribe to node status change messages for visible nodes only\&. The tuple \fI{node_type, visible}\fR\& will be included in the \fIInfo\fR\& list\&.
.TP 2
.B
\fIhidden\fR\&:
Subscribe to node status change messages for hidden nodes only\&. The tuple \fI{node_type, hidden}\fR\& will be included in the \fIInfo\fR\& list\&.
.TP 2
.B
\fIall\fR\&:
Subscribe to node status change messages for both visible and hidden nodes\&. The tuple \fI{node_type, visible | hidden}\fR\& will be included in the \fIInfo\fR\& list\&.
.RE
.RS 2
.LP
If no \fI{node_type, NodeType}\fR\& option has been given\&. The caller will subscribe for status change messages for visible nodes only, but \fIno\fR\&  \fI{node_type, visible}\fR\& tuple will be included in the \fIInfo\fR\& list\&.
.RE

.TP 2
.B
\fInodedown_reason\fR\&:
The tuple \fI{nodedown_reason, Reason}\fR\& will be included in the \fIInfo\fR\& list for \fInodedown\fR\& messages\&.
.RS 2
.LP
See the documentation of the \fInodedown_reason => boolean()\fR\& association above for information about possible \fIReason\fR\& values\&.
.RE

.RE
.LP
Example:
.LP
.nf

(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> 
        
.fi
.RE

.LP
.nf

.B
set_net_ticktime(NetTicktime) -> Res
.br
.fi
.br
.nf

.B
set_net_ticktime(NetTicktime, TransitionPeriod) -> Res
.br
.fi
.br
.RS
.LP
Types:

.RS 3
NetTicktime = integer() >= 1
.br
TransitionPeriod = integer() >= 0
.br
Res = 
.br
    unchanged | change_initiated |
.br
    {ongoing_change_to, NewNetTicktime}
.br
NewNetTicktime = integer() >= 1
.br
.RE
.RE
.RS
.LP
Sets \fInet_ticktime\fR\& (see \fIkernel(7)\fR\&) to \fINetTicktime\fR\& seconds\&. \fITransitionPeriod\fR\& defaults to \fI60\fR\&\&.
.LP
Some definitions:
.RS 2
.TP 2
.B
Minimum transition traffic interval (\fIMTTI\fR\&):
\fIminimum(NetTicktime, PreviousNetTicktime)*1000 div 4\fR\& milliseconds\&.
.TP 2
.B
Transition period:
The time of the least number of consecutive \fIMTTI\fR\&s to cover \fITransitionPeriod\fR\& seconds following the call to \fIset_net_ticktime/2\fR\& (that is, ((\fITransitionPeriod*1000 - 1) div MTTI + 1)*MTTI\fR\& milliseconds)\&.
.RE
.LP
If \fINetTicktime < PreviousNetTicktime\fR\&, the \fInet_ticktime\fR\& change is done at the end of the transition period; otherwise at the beginning\&. During the transition period, \fInet_kernel\fR\& ensures that there is outgoing traffic on all connections at least every \fIMTTI\fR\& millisecond\&.
.LP

.RS -4
.B
Note:
.RE
The \fInet_ticktime\fR\& changes must be initiated on all nodes in the network (with the same \fINetTicktime\fR\&) before the end of any transition period on any node; otherwise connections can erroneously be disconnected\&.

.LP
Returns one of the following:
.RS 2
.TP 2
.B
\fIunchanged\fR\&:
\fInet_ticktime\fR\& already has the value of \fINetTicktime\fR\& and is left unchanged\&.
.TP 2
.B
\fIchange_initiated\fR\&:
\fInet_kernel\fR\& initiated the change of \fInet_ticktime\fR\& to \fINetTicktime\fR\& seconds\&.
.TP 2
.B
\fI{ongoing_change_to, NewNetTicktime}\fR\&:
The request is \fIignored\fR\& because \fInet_kernel\fR\& is busy changing \fInet_ticktime\fR\& to \fINewNetTicktime\fR\& seconds\&.
.RE
.RE

.LP
.nf

.B
setopts(Node, Options) -> ok | {error, Reason} | ignored
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Node = node() | new
.br
Options = [inet:socket_setopt()]
.br
Reason = inet:posix() | noconnection
.br
.RE
.RE
.RS
.LP
Set one or more options for distribution sockets\&. Argument \fINode\fR\& can be either one node name or the atom \fInew\fR\& to affect the distribution sockets of all future connected nodes\&.
.LP
The return value is the same as from \fIinet:setopts/2\fR\& or \fI{error, noconnection}\fR\& if \fINode\fR\& is not a connected node or \fInew\fR\&\&.
.LP
If \fINode\fR\& is \fInew\fR\& the \fIOptions\fR\& will then also be added to kernel configuration parameters inet_dist_listen_options and inet_dist_connect_options\&.
.LP
Returns \fIignored\fR\& if the local node is not alive\&.
.RE

.LP
.nf

.B
start(Name, Options) -> {ok, pid()} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Options = 
.br
    #{name_domain => NameDomain,
.br
      net_ticktime => NetTickTime,
.br
      net_tickintensity => NetTickIntensity,
.br
      dist_listen => boolean(),
.br
      hidden => boolean()}
.br
Name = atom()
.br
NameDomain = shortnames | longnames
.br
NetTickTime = integer() >= 1
.br
NetTickIntensity = 4\&.\&.1000
.br
Reason = {already_started, pid()} | term()
.br
.RE
.RE
.RS
.LP
Turns a non-distributed node into a distributed node by starting \fInet_kernel\fR\& and other necessary processes\&.
.LP
If \fIName\fR\& is set to \fI\fIundefined\fR\&\fR\& the distribution will be started to request a dynamic node name from the first node it connects to\&. See  Dynamic Node Name\&. Setting \fIName\fR\& to \fIundefined\fR\& implies options \fIdist_listen => false\fR\& and \fIhidden => true\fR\&\&.
.LP
Currently supported options:
.RS 2
.TP 2
.B
\fIname_domain => NameDomain\fR\&:
Determines the host name part of the node name\&. If \fINameDomain\fR\& equals \fIlongnames\fR\&, fully qualified domain names will be used which also is the default\&. If \fINameDomain\fR\& equals \fIshortnames\fR\&, only the short name of the host will be used\&.
.TP 2
.B
\fInet_ticktime => NetTickTime\fR\&:
\fINet tick time\fR\&  to use in seconds\&. Defaults to the value of the \fInet_ticktime\fR\& \fIkernel(7)\fR\& parameter\&. For more information about \fInet tick time\fR\& , see the \fIkernel\fR\& parameter\&. However, note that if the value of the \fIkernel\fR\& parameter is invalid, it will silently be replaced by a valid value, but if an invalid \fINetTickTime\fR\& value is passed as option value to this function, the call will fail\&.
.TP 2
.B
\fInet_tickintensity => NetTickIntensity\fR\&:
\fINet tick intensity\fR\&  to use\&. Defaults to the value of the \fInet_tickintensity\fR\& \fIkernel(7)\fR\& parameter\&. For more information about \fInet tick intensity\fR\& , see the \fIkernel\fR\& parameter\&. However, note that if the value of the \fIkernel\fR\& parameter is invalid, it will silently be replaced by a valid value, but if an invalid \fINetTickIntensity\fR\& value is passed as option value to this function, the call will fail\&.
.TP 2
.B
\fIdist_listen => boolean()\fR\&:
Enable or disable listening for incoming connections\&. Defaults to the value of the \fI-dist_listen\fR\& \fIerl\fR\& command line argument\&. Note that \fIdist_listen => false\fR\& implies \fIhidden => true\fR\&\&.
.RS 2
.LP
If \fIundefined\fR\& has been passed as \fIName\fR\&, the \fIdist_listen\fR\& option will be overridden with \fIdist_listen => false\fR\&\&.
.RE

.TP 2
.B
\fIhidden => boolean()\fR\&:
Enable or disable hidden node\&. Defaults to \fItrue\fR\& if the \fI-hidden\fR\& \fIerl\fR\& command line argument has been passed; otherwise \fIfalse\fR\&\&.
.RS 2
.LP
If \fIundefined\fR\& has been passed as \fIName\fR\&, or the option \fIdist_listen\fR\& equals \fIfalse\fR\&, the \fIhidden\fR\& option will be overridden with \fIhidden => true\fR\&\&.
.RE

.RE
.RE

.LP
.nf

.B
start(Options) -> {ok, pid()} | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Options = [Name | NameDomain | TickTime, \&.\&.\&.]
.br
Name = atom()
.br
NameDomain = shortnames | longnames
.br
TickTime = integer() >= 1
.br
Reason = {already_started, pid()} | term()
.br
.RE
.RE
.RS
.LP

.RS -4
.B
Warning:
.RE
\fIstart/1\fR\& is deprecated\&. Use \fIstart/2\fR\& instead\&.

.LP
Turns a non-distributed node into a distributed node by starting \fInet_kernel\fR\& and other necessary processes\&.
.LP
\fIOptions\fR\& list can only be exactly one of the following lists (order is imporant):
.RS 2
.TP 2
.B
\fI[Name]\fR\&:
The same as \fInet_kernel:start([Name, longnames, 15000])\fR\&\&.
.TP 2
.B
\fI[Name, NameDomain]\fR\&:
The same as \fInet_kernel:start([Name, NameDomain, 15000])\fR\&\&.
.TP 2
.B
\fI[Name, NameDomain, TickTime]\fR\&:
The same as \fInet_kernel:start(Name, #{name_domain => NameDomain, net_ticktime => ((TickTime*4-1) div 1000) + 1, net_tickintensity => 4})\fR\&\&. Note that \fITickTime\fR\& is \fInot\fR\&  the same as net tick time expressed in milliseconds\&. \fITickTime\fR\& is the time between ticks when net tick intensity equals \fI4\fR\&\&.
.RE
.RE

.LP
.nf

.B
stop() -> ok | {error, Reason}
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Reason = not_allowed | not_found
.br
.RE
.RE
.RS
.LP
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 \fIstart/2\fR\&, otherwise \fI{error, not_allowed}\fR\& is returned\&. Returns \fI{error, not_found}\fR\& if the local node is not alive\&.
.RE