[SNMP4J] Protocol mismatch (or socket errors in general) leadto many connection attempts using snmp4j 1.10.2

[Frank Fock]

Hi Warren,

I think I have fixed now the problem you reported.
Please try out the current snapshot at:
https://server.oosnmp.net/dist/snapshot/org/snmp4j/snmp4j/1.11-SNAPSHOT/

Best regards,
Frank

On 30.12.2009 14:14, Warren Cooper wrote:
> (Resending to include the mailing list in case you missed my followup
> questions. Thanks)
>
>  >...Any suggestions are welcome...
> How about if the the queued entries obey the retry configuration
> setting? i.e. if the retry count is set to 1, then a message in the
> pending list will only register for OP_CONNECT one more time. After that
> it is simply discarded from the pending list.
>
> I am seeing cases where the socket entry is null in connectChannel( )
> because the socket channel fails this check:
> --> if (sc.equals(entry.getSocket().getChannel())) { <--
> So no event is fired and that warning message
> --> logger.warn("Message not found on finish connection"); <--
> is sent instead. Once a few messages are queued into the pending member
> and the server socket connection is down, this really churns cpu
> streaming an endless amount of these 'Message not found...' messages and
> eats memory quickly if the traps include variables w/ alot of data.
>
> I'm investigating overriding the DefaultTcpTransportMapping class, but I
> just wanted to make certain you understood the potential impact of the
> problem I am reporting.
> -thanks
>
> Frank Fock wrote:
>> Warren,
>>
>> You can (and should) handle such a situation in your code
>> by implementing a TransportStateListener and add it
>> to your TcpTransportMapping.
>>
>> I have no idea how this could be solved in a generic
>> way without a negative impact on existing code.
>> Any suggestions are welcome.
>>
>> Regards,
>> Frank
>>
>> On 28.12.2009 15:57, Warren Cooper wrote:
>>> If there is a connection problem between an SNMP agent configured to
>>> send TCP in its attempt to send events to an SNMP server, and there is
>>> a problem making a connection, many attempts to send the events will
>>> fail. ( It's a problem because the pending list (member in
>>> DefaultTCPTransportMapping) will continue to grow.
>>>
>>> To see the problem, configure an SNMP client to send 40 events over TCP
>>> to a SNMP server expecting UDP.
>>> (But this problem would happen in any case where if
>>> (entry.getSocket().isConnected()) ) check in processPending() is not
>>> true.
>>> As you know, this is a serious problem since CPU resources are impacted
>>> and memory could eventually be exhausted if the problem continues for
>>> over an extended period of time and enough events are written to the
>>> 'pending' list object instance.
>>>
>>> thanks
>>> _______________________________________________
>>> SNMP4J mailing list
>>> SNMP4J at agentpp.org
>>> http://lists.agentpp.org/mailman/listinfo/snmp4j
>>
>

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