[SNMP4J] Behaviour of ResponseListener in SNMP V3
Peter Verthez
Peter.Verthez at nokia.com
Fri Oct 7 08:18:14 CEST 2016
Ah, maybe I copied the wrong traces then and that is the source of the
confusion (we have a mix of SNMPv2 and v3 agents).
Let me check...
Thanks,
Peter.
On 6/10/2016 21:45, Frank Fock wrote:
> Hi Peter,
>
> The PDU that is send is a SNMPv2c GET request and not a v3 request.
> So this cannot be an issue with the USM or other v3 processing.
>
> To be able to reproduce the issue I might need more details. If it is
> indeed
> a v3 request, I would like to have the log for it. In addition,
> is the "unknown user" locally unknown the the USM of the command
> sender or remotely unknown to the command responder.
>
> If locally unknown, a exception is thrown during the send call.
>
> Best regards,
> Frank
>
> Am 06.10.2016 um 09:45 schrieb Peter Verthez:
>> Hi Frank,
>>
>> The PDU instance is not used in another thread, only in this one. All
>> normal functionality works properly (we started to use async requests
>> 1.5 years ago), except for this timeout due to a wrong security name
>> being used. I'm not sure whether that is a new regression or
>> something that wasn't tested before by our test team.
>>
>> I'm not sure which further information I have to give, I can't
>> provide the full source code as this is a proprietary product. If you
>> want me to debug something specific I can do that.
>>
>> Best regards,
>> Peter.
>>
>>
>> On 5/10/2016 22:55, Frank Fock wrote:
>>> Hi Peter,
>>>
>>> From the provided send call alone, I cannot verify if the parameters
>>> are correctly
>>> setup. The SnmpUserTarget.this, for example, might not work if
>>> called in a constructor
>>> of that class.
>>>
>>> The pdu instance might be used concurrently by another thread (with
>>> same or different
>>> request ID), which would corrupt the pending request management.
>>>
>>> Best regards,
>>> Frank
>>>
>>> Am 05.10.2016 um 08:14 schrieb Peter Verthez:
>>>> Hi Frank,
>>>>
>>>> The call of the send method was in the last line of my code
>>>> snippet: session is an Snmp object.
>>>>
>>>> Best regards,
>>>> Peter.
>>>>
>>>>
>>>> On 4/10/2016 20:12, Frank Fock wrote:
>>>>>
>>>>> Hi Peter,
>>>>>
>>>>> How do call the send method? Is the listener set there?
>>>>> All fields null should not happen normally....
>>>>>
>>>>> Best regards,
>>>>> Frank
>>>>>
>>>>> Am 04.10.2016 um 11:18 schrieb Peter Verthez:
>>>>>> Hi Frank,
>>>>>>
>>>>>> Our code is simply:
>>>>>>
>>>>>> ResponseListener respListener = new
>>>>>> ResponseListener() {
>>>>>> @Override
>>>>>> public void onResponse(ResponseEvent
>>>>>> event) {
>>>>>> // canceling is required as per
>>>>>> SNMP4J documentation
>>>>>> ((Snmp)event.getSource()).cancel(event.getRequest(), this);
>>>>>> PDU response = event.getResponse();
>>>>>> updateStats(session, agentId,
>>>>>> startTime, response);
>>>>>> listener.onResponse(response, event.getUserObject());
>>>>>> }
>>>>>> };
>>>>>>
>>>>>> session.send(pdu, SnmpUserTarget.this,
>>>>>> userContext, respListener);
>>>>>>
>>>>>> It doesn't reach even the first line of the onResponse method.
>>>>>>
>>>>>> I've been debugging a little, and the PendingRequest.run() method
>>>>>> in the Snmp class is always being exited because all fields are
>>>>>> null, and so it never calls the onResponse method on the
>>>>>> listener. This is also what the debug message says:
>>>>>>
>>>>>> 2016-09-28 16:43:36,861 DEBUG [SNMP4J Timer]-[org.snmp4j.Snmp]
>>>>>> PendingRequest canceled key=null, pdu=null, target=null,
>>>>>> transport=null, listener=null
>>>>>>
>>>>>> I've then put a breakpoint in the cancel() method, and it gets
>>>>>> run when the following report is coming in (copied from the
>>>>>> debugger):
>>>>>>
>>>>>> REPORT[{contextEngineID=80:00:02:7d:03:00:90:d0:6d:fa:bc,
>>>>>> contextName=nt}, requestID=0, errorStatus=0, errorIndex=0,
>>>>>> VBS[1.3.6.1.6.3.15.1.1.3.0 = 18]]
>>>>>>
>>>>>> Best regards,
>>>>>> Peter.
>>>>>>
>>>>>>
>>>>>> On 3/10/2016 23:06, Frank Fock wrote:
>>>>>>> Hi Peter,
>>>>>>>
>>>>>>> Yes, the ResponseEvent should be returned after the timeout with
>>>>>>> a null response.
>>>>>>> From the log, it is unclear why you do not get the event. Is
>>>>>>> there an if-statement
>>>>>>> that ignores the ResponseEvent with null response in your code?
>>>>>>>
>>>>>>> Best regards,
>>>>>>> Frank
>>>>>>>
>>>>>>> Am 30.09.2016 um 10:12 schrieb Peter Verthez:
>>>>>>>> Hi Frank,
>>>>>>>>
>>>>>>>> If we are using asynchronous SNMP calls with SNMPv3, what
>>>>>>>> should be the behaviour in case of timeout, when you used wrong
>>>>>>>> credentials such as a wrong user name. Should the
>>>>>>>> ResponseListener always be triggered, with event.getResponse()
>>>>>>>> = null, after the timeout?
>>>>>>>>
>>>>>>>> I would expect that, but it looks like this is not what I'm
>>>>>>>> seeing: the ResponseListener does not seem to be triggered in
>>>>>>>> that case. So this means that our application never knows that
>>>>>>>> a timeout occurred. We are using currently SNMP4J 2.5.0. Debug
>>>>>>>> logging from SNMP4J:
>>>>>>>>
>>>>>>>> 2016-09-28 16:43:31,768 DEBUG
>>>>>>>> [JM-49-Ping-Ping-4]-[org.snmp4j.Snmp] Running pending async
>>>>>>>> request with handle PduHandle[1071987217] and retry count left 1
>>>>>>>> 2016-09-28 16:43:31,768 DEBUG
>>>>>>>> [JM-49-Ping-Ping-4]-[org.snmp4j.transport.DefaultUdpTransportMapping]
>>>>>>>> Sending message to 135.249.41.44/161 with length 268:
>>>>>>>> 30:82:01:08:02:01:01:04:06:70:75:62:6c:69:63:a0:81:fa:02:04:3f:e5:3a:11:02:01:00:02:01:00:30:81:eb:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:09:03:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:06:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:0b:09:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:0b:02:00:05:00:30:12:06:0e:2b:06:01:04:01:84:7d:3d:01:23:3c:03:02:00:05:00:30:0c:06:08:2b:06:01:02:01:01:03:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:07:00:05:00:30:0c:06:08:2b:06:01:02:01:01:02:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:03:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:09:0d:00:05:00:30:12:06:0e:2b:06:01:04:01:84:7d:3d:01:17:02:01:04:01:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:09:1c:01:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:09:1c:02:00:05:00
>>>>>>>>
>>>>>>>> 2016-09-28 16:43:35,771 DEBUG [SNMP4J Timer]-[org.snmp4j.Snmp]
>>>>>>>> Running pending async request with handle PduHandle[1071987217]
>>>>>>>> and retry count left 0
>>>>>>>> 2016-09-28 16:43:35,771 DEBUG [SNMP4J
>>>>>>>> Timer]-[org.snmp4j.transport.DefaultUdpTransportMapping]
>>>>>>>> Sending message to 135.249.41.44/161 with length 268:
>>>>>>>> 30:82:01:08:02:01:01:04:06:70:75:62:6c:69:63:a0:81:fa:02:04:3f:e5:3a:11:02:01:00:02:01:00:30:81:eb:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:09:03:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:06:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:0b:09:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:0b:02:00:05:00:30:12:06:0e:2b:06:01:04:01:84:7d:3d:01:23:3c:03:02:00:05:00:30:0c:06:08:2b:06:01:02:01:01:03:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:07:00:05:00:30:0c:06:08:2b:06:01:02:01:01:02:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:17:01:03:00:05:00:30:10:06:0c:2b:06:01:04:01:84:7d:3d:01:09:0d:00:05:00:30:12:06:0e:2b:06:01:04:01:84:7d:3d:01:17:02:01:04:01:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:09:1c:01:00:05:00:30:11:06:0d:2b:06:01:04:01:84:7d:3d:01:09:1c:02:00:05:00
>>>>>>>>
>>>>>>>> 2016-09-28 16:43:36,861 DEBUG [SNMP4J Timer]-[org.snmp4j.Snmp]
>>>>>>>> PendingRequest canceled key=null, pdu=null, target=null,
>>>>>>>> transport=null, listener=null
>>>>>>>> 2016-09-28 16:43:43,771 DEBUG [SNMP4J Timer]-[org.snmp4j.Snmp]
>>>>>>>> Request timed out: 1071987217
>>>>>>>> 2016-09-28 16:43:43,772 DEBUG [SNMP4J Timer]-[org.snmp4j.Snmp]
>>>>>>>> Cancelling pending request with handle PduHandle[1071987217]
>>>>>>>>
>>>>>>>> Best regards,
>>>>>>>> Peter.
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>>
>
--
Peter Verthez
Systems Engineer Network Mgt.
Tel: (+32) 3 240 84 50 | Alcanet:
Fax: (+32) 3 240 84 59 | (6)2605
Nokia Corporation
Copernicuslaan 50, 2018 Antwerp, Belgium
Fortis 220-0002334-42
VAT BE 0404 621 642 Register of Legal Entities Antwerp
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