epmd(1) User Commands epmd(1)NAMEepmd - Erlang Port Mapper Daemon
DESCRIPTION
This daemon acts as a name server on all hosts involved in distributed
Erlang computations. When an Erlang node starts, the node has a name
and it obtains an address from the host OS kernel. The name and the
address are sent to the epmd daemon running on the local host. In a
TCP/IP environment, the address consists of the IP address and a port
number. The name of the node is an atom on the form of Name@Node. The
job of the epmd daemon is to keep track of which node name listens on
which address. Hence, epmd map symbolic node names to machine
addresses.
The daemon is started automatically by the Erlang start-up script.
The program epmd can also be used for a variety of other purposes, for
example checking the DNS (Domain Name System) configuration of a host.
EXPORTSepmd [-daemon]
Starts a name server as a daemon. If it has no argument, the
epmd runs as a normal program with the controlling terminal of
the shell in which it is started. Normally, it should run as a
daemon.
epmd-names
Requests the names of the local Erlang nodes epmd has regis‐
tered.
epmd-kill
Kills the epmd process.
epmd-help
Write short info about the usage including some debugging
options not listed here.
ENVIRONMENT VARIABLES
ERL_EPMD_PORT
This environment variable can contain the port number epmd will
use. The default port will work fine in most cases. A different
port can be specified to allow several instances of epmd, repre‐
senting independent clusters of nodes, to co-exist on the same
host. All nodes in a cluster must use the same epmd port number.
LOGGING
On some operating systems syslog will be used for error reporting when
epmd runs as an daemon. To enable the error logging you have to edit
/etc/syslog.conf file and add an entry
!epmd
*.*<TABs>/var/log/epmd.log
where <TABs> are at least one real tab character. Spaces will silently
be ignored.
Ericsson AB erts 5.7.4 epmd(1)
