[SNMP4J] About IllegalStateException
Frank Fock
fock at agentpp.com
Fri Dec 15 22:25:49 CET 2006
Hi,
? wrote:
> $)CHi,
>
> I have interested the problems you wrote since I had found the behavior
> of the Snmp class something incorrect.
Could you provide details? Or is it the IllegalStateException issue?
> In my case, I wrote a new class send PDUs to target and process the timeout
> because I made a conclusion that the JAVA timer itself can produce a problem
> on resource handling when we try to make up well organized software architecture.
Why should be using java.util.Timer an architectural problem?
> And finally I use very little time slice of CPU and have succeeded to get timeout result
> under 5msec tolerance.
Without using a real-time Java system such time specifications
have no significance. Using a polling Thread that sleeps
unconditional either uses more CPU cycles than required or
waste responsiveness by waiting.
Best regards,
Frank
>
> My aproach is use just another one watch up thread and polling the
> SNMP responses of all PDUs we have send.
>
> the part of source code
>
> while(true)
> {
> try
> {
> sleep(0,1);
>
> for(..) // monitoring results of..
> {
> //some code stuffs that watch up
> ..
> sleep(0,1);
> }
> }
> }
>
> I hope my approch can be helpful to you.
>
> Regards,
> Steve Jin
>
> --------------------- Original Messages ---------------------
> From: snmp4j-request at agentpp.orgSubject: SNMP4J Digest, Vol 35, Issue 9
> Subject:
>
>
>
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> Today's Topics:
>
> 1. IllegalStateException in Snmp.send() (Alberto)
> 2. Virtual SNMPv3 Server (Keary Parinis)
> 3. CHANGE OF THE SENDER IP (RC_Insignia)
> 4. Re: IllegalStateException in Snmp.send() (Frank Fock)
> 5. Re: CHANGE OF THE SENDER IP (Frank Fock)
> 6. Re: Virtual SNMPv3 Server (Frank Fock)
> 7. Re: Virtual SNMPv3 Server (Keary Parinis)
> 8. R: Re: [SNMP4J] IllegalStateException in Snmp.send() (Alberto)
> 9. Re: R: Re: [SNMP4J] IllegalStateException in Snmp.send()
> (Fabian Nart)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 13 Dec 2006 16:38:28 +0100 (CET)
> From: Alberto
> Subject: [SNMP4J] IllegalStateException in Snmp.send()
> To: snmp4j at agentpp.org
> Message-ID:
> <32705453.1240591166024308212.JavaMail.defaultUser at defaultHost>
> Content-Type: text/plain;charset="UTF-8"
>
> Hello,
> I refer to the correction provided in v1.7.1 and described by Frank in email
> below.
> Since I got the same problem in my project, I downloaded the SNMP4J version
> 1.7.5 and reproduced the error with log4j logs enabled.
> Here the result (just reported the PduHandle with the problem, but if you need
> I have the complete logs):
>
> 13/12/2006 14:30:30:131 DEBUG [pool-10-thread-22] [Log4jLogAdapter.debug] New
> pending request with handle PduHandle[1826954335]
> ....
> 13/12/2006 14:30:45:579 DEBUG [Timer-15] [Log4jLogAdapter.debug] Running
> pending request (3 left) with handle: PduHandle[1826954335]
> ....
> 13/12/2006 14:31:00:587 DEBUG [Timer-15] [Log4jLogAdapter.debug] Running
> pending request (2 left) with handle: PduHandle[1826954335]
> ....
> 13/12/2006 14:31:00:589 DEBUG [SNMPDriverDispatchPool.2] [Log4jLogAdapter.
> debug] Looking up pending request with handle PduHandle[1826954335]
> ....
> 13/12/2006 14:31:00:591 ERROR [Timer-15] [Log4jLogAdapter.error] Failed to
> process pending request PduHandle[1826954335] because Task already scheduled or
> cancelled
> java.lang.IllegalStateException: Task already scheduled or cancelled
> at java.util.Timer.sched(Timer.java:358)
> at java.util.Timer.schedule(Timer.java:170)
> at org.snmp4j.Snmp$PendingRequest.run(Snmp.java:1426)
> at java.util.TimerThread.mainLoop(Timer.java:512)
> at java.util.TimerThread.run(Timer.java:462)
> ....
> 13/12/2006 14:31:00:590 DEBUG [pool-10-thread-22] [Log4jLogAdapter.debug]
> Removed pending request with handle: PduHandle[1826954335]
> ....
>
> It seems there is a relation between the time the Timer-15 is checking the
> handle for the second time (14:31:00:587) and the time the answer comes (14:31:
> 00:589). They are really very closed one to the other.
> Maybe a synchronization problem among threads?
>
> Of course, after Timer-15 thread dies, no Snmp primitive to the agent is
> possible anymore and my application has to be restarted.
>
> Can you help, please?
> Regards,
> Alberto
>
>
> Frank wrote:
>
>> Hi Fabian,
>>
>> We can catch only a RuntimeException and rethrow it. I have
>> changed the code as follows for v1.7.1:
>>
>> /**
>> * run
>> */
>> public synchronized void run() {
>> try {
>> if ((!finished) && (retryCount > 0)) {
>> ...
>> }
>> }
>> catch (RuntimeException ex) {
>> logger.error("Failed to process pending request "+key+
>> " because"+ex.getMessage(), ex);
>> throw ex;
>> }
>>
>> Best regards,
>> Frank
>>
>
>
> --------------------
> Alberto Mascheroni
> Mob. +39-333-6314222
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 13 Dec 2006 08:13:54 -0800 (PST)
> From: Keary Parinis
> Subject: [SNMP4J] Virtual SNMPv3 Server
> To: snmp4j at agentpp.org
> Message-ID: <20061213161354.5639.qmail at web60715.mail.yahoo.com>
> Content-Type: text/plain; charset=ascii
>
> Hi,
>
> I use a java app at work that collects router information using SNMP4J and we are currently using SNMP version 2. We will upgrade to version 3 shortly. I see the code example for version 3 in the Java docs. I would like to re-code my java app and test before the upgrade. Does anyone know how to create a virtual SNMPv3 server with SNMP4J? I just need something that will accept USM authentication and reply to a get request. I think I can create something simple with a ServerSocket running on port 162. Is there something out there that does this. I had no luck with google for the past few hours. Thanks in advance.
>
>
> K E
>
> ------------------------------
>
> Message: 3
> Date: Wed, 13 Dec 2006 11:55:45 -0400
> From: "RC_Insignia"
> Subject: [SNMP4J] CHANGE OF THE SENDER IP
> To:
> Message-ID:
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> In my computer I have 4 differents IP4s because VPN requisites I need to
> change the sender IP different from the localhost.
> How I can do that and send the trps trough a specific IP in my machine ?
>
> Thanks in advance,
>
> Ricardo Carrillo
>
>
>
> ------------------------------
>
> Message: 4
> Date: Thu, 14 Dec 2006 00:55:52 +0100
> From: Frank Fock
> Subject: Re: [SNMP4J] IllegalStateException in Snmp.send()
> To: Alberto
> Cc: snmp4j at agentpp.org
> Message-ID: <45809308.105 at agentpp.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> Hello Alberto,
>
> You wrote that you had to restart your application
> in order to use your Snmp instance again after
> having caught the error below. This indicates,
> that the timer referred to in the exception,
> had been canceled. That means that your code
> somewhere called Snmp.close() while requests
> where pending.
>
> That is how it is supposed to work: If you close
> the Snmp instance, then it is shutdown and
> cannot be used again. You will need to instantiate
> a new Snmp instance.
>
> So please do not call Snmp.close() between two
> queries!
>
> Hope this helps.
>
> Best regards,
> Frank
>
> Alberto wrote:
>> Hello,
>> I refer to the correction provided in v1.7.1 and described by Frank in email
>> below.
>> Since I got the same problem in my project, I downloaded the SNMP4J version
>> 1.7.5 and reproduced the error with log4j logs enabled.
>> Here the result (just reported the PduHandle with the problem, but if you need
>> I have the complete logs):
>>
>> 13/12/2006 14:30:30:131 DEBUG [pool-10-thread-22] [Log4jLogAdapter.debug] New
>> pending request with handle PduHandle[1826954335]
>> ...
>> 13/12/2006 14:30:45:579 DEBUG [Timer-15] [Log4jLogAdapter.debug] Running
>> pending request (3 left) with handle: PduHandle[1826954335]
>> ...
>> 13/12/2006 14:31:00:587 DEBUG [Timer-15] [Log4jLogAdapter.debug] Running
>> pending request (2 left) with handle: PduHandle[1826954335]
>> ...
>> 13/12/2006 14:31:00:589 DEBUG [SNMPDriverDispatchPool.2] [Log4jLogAdapter.
>> debug] Looking up pending request with handle PduHandle[1826954335]
>> ...
>> 13/12/2006 14:31:00:591 ERROR [Timer-15] [Log4jLogAdapter.error] Failed to
>> process pending request PduHandle[1826954335] because Task already scheduled or
>> cancelled
>> java.lang.IllegalStateException: Task already scheduled or cancelled
>> at java.util.Timer.sched(Timer.java:358)
>> at java.util.Timer.schedule(Timer.java:170)
>> at org.snmp4j.Snmp$PendingRequest.run(Snmp.java:1426)
>> at java.util.TimerThread.mainLoop(Timer.java:512)
>> at java.util.TimerThread.run(Timer.java:462)
>> ...
>> 13/12/2006 14:31:00:590 DEBUG [pool-10-thread-22] [Log4jLogAdapter.debug]
>> Removed pending request with handle: PduHandle[1826954335]
>> ...
>>
>> It seems there is a relation between the time the Timer-15 is checking the
>> handle for the second time (14:31:00:587) and the time the answer comes (14:31:
>> 00:589). They are really very closed one to the other.
>> Maybe a synchronization problem among threads?
>>
>> Of course, after Timer-15 thread dies, no Snmp primitive to the agent is
>> possible anymore and my application has to be restarted.
>>
>> Can you help, please?
>> Regards,
>> Alberto
>>
>>
>> Frank wrote:
>>
>>> Hi Fabian,
>>>
>>> We can catch only a RuntimeException and rethrow it. I have
>>> changed the code as follows for v1.7.1:
>>>
>>> /**
>>> * run
>>> */
>>> public synchronized void run() {
>>> try {
>>> if ((!finished) && (retryCount > 0)) {
>>> ...
>>> }
>>> }
>>> catch (RuntimeException ex) {
>>> logger.error("Failed to process pending request "+key+
>>> " because"+ex.getMessage(), ex);
>>> throw ex;
>>> }
>>>
>>> Best regards,
>>> Frank
>>>
>>
>> --------------------
>> Alberto Mascheroni
>> Mob. +39-333-6314222
>> _______________________________________________
>> SNMP4J mailing list
>> SNMP4J at agentpp.org
>> http://lists.agentpp.org/mailman/listinfo/snmp4j
>
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