[erlang-bugs] epmd not cleaning up node name if node is down.

Kenneth Lundin <>
Mon Aug 18 15:42:05 CEST 2008


Can you start epmd manually like this "epmd -debug" before you start the
Erlang nodes on the same host.

You will then get debug printouts from empd showing when it register
and unregister E-nodes.

/Kenneth

2008/8/18 Zbyszek Żółkiewski <>:
> so? no one have any idea?
>
> On Fri, Aug 15, 2008 at 14:22, Zbyszek Żółkiewski <>
> wrote:
>>
>> Hello, thanks for the reply,
>>
>> System is Debian 4.0, custom compiled erlang OTP R11B-5,
>> Erlang (BEAM) emulator version 5.5.5 [source] [smp:2] [async-threads:0]
>> [hipe] [kernel-poll:true]
>> (so the nodes are running with +K true -smp options)
>>
>> software that we use is ejabberd xmpp server, we are using cluster mode
>> with 3 nodes (2 on one server and 1 on other server), in this case node was
>> crashed,
>> but the same situation appear on both servers, if i stop node with
>> init:stop()., ctrl+G, k 1, q combination - so quite legaly exiting and
>> shuting down node...
>>
>> so do you have any clue what can cause that epmd is not removing entry
>> from its table? and what we can do to determine problem, and finaly, is
>> there any way of clear epmd table from invalid entries?
>>
>> thanks,
>>
>>
>>
>> 2008/8/15 Kenneth Lundin <>
>>>
>>> Hi,
>>>
>>> The normal and correct behaviour is that a node is unregistered from
>>> epmd when it is shutdown.
>>> each Erlang node that register to epmd establishes and keep an open
>>> tcp connection towards epmd.
>>> When that connection is broken the Erlang node is unregistered.
>>>
>>> On what OS is this?
>>> How is the Erlang node shutdown?
>>>
>>> I just run an example on Suse Linux where I create 2 Erlang nodes like
>>> this:
>>>
>>> erl -sname a
>>>
>>> and in another shell
>>>
>>> erl -sname b
>>>
>>> In a third shell epmd -names reported both nodes.
>>>
>>> I then tried to terminate one of the nodes normally and epmd -names
>>> correctly reported that there
>>> is only one node left.
>>>
>>> i started the second node again and epmd -names reported the 2 nodes.
>>>
>>> I killed one of the nodes with kill -9 and again epmd -names reported
>>> only one node as expected.
>>>
>>> There must be something else causing the behaviour on your system.
>>>
>>> /Kenneth Erlang/OTP team Ericsson
>>>
>>
>>
>> --
>> pozdrawiam,
>> Zbyszek Żółkiewski
>
>
>
> --
> pozdrawiam,
> Zbyszek Żółkiewski
>
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