writecommit failed

[HarelAshwal]

Hi All,

I'm having a SET Sequence with SNMP using the writeCommit method:

def writeCommit(self, name, val, *args):
print " Setting var..."
obj = setValue(fullPath,val)
if (obj == 'err') :
raise 'some error'

I'm trying to fail the write sequence in case the set operation didn't passed OK.
but, when i'm raising an error the entire agent is stopping.
how do i do that? how do i inform the SNMP client the set operation failed without stopping the agent?

[etingof]

Depending on which SNMP error you are trying to convey to the client, you should only raise exceptions based on the pysnmp.smi.error.SmiError class. For example NotWritableError or NoAccessError.

Also note that it is generally cheaper to fail in the writeTest() method which is called for every variable in the SET request prior to writeCommit. That's because if you fail in writeCommit(), the rest of the variables in the SET query that were "set" prior to the failure would have to be "unset".

Here is a baseline implementation for your reference.

[HarelAshwal]

LK"I

Thanks for the quick replay.
here is my code:

main function to start the agent:
def serve_forever(self):
print "Starting agent"
self._snmpEngine.transportDispatcher.jobStarted(1)
try:
self._snmpEngine.transportDispatcher.runDispatcher()
except:
self._snmpEngine.transportDispatcher.closeDispatcher()
raise

and the writeTest: (raising the ValueConstraintError from SmiError)
def writeTest(self, name, idx, acInfo, *args):
print " Testing var..."
raise error.ValueConstraintError()

but it still just fails and stops the snmp engine:
Testing var...
Traceback (most recent call last):
File "C:\projects_node\CompleteDemo\SNMP\SNMP.py", line 265, in
agent.serve_forever()
File "C:\projects_node\CompleteDemo\SNMP\SNMP.py", line 193, in serve_forever
self._snmpEngine.transportDispatcher.runDispatcher()
File "C:\Python27\lib\site-packages\pysnmp\carrier\asyncore\dispatch.py", line
49, in runDispatcher
raise PySnmpError('poll error: %s' % ';'.join(format_exception(*exc_info()))
)
PySnmpError: poll error: Traceback (most recent call last):
; File "C:\Python27\lib\site-packages\pysnmp\carrier\asyncore\dispatch.py", lin
e 45, in runDispatcher
use_poll=True, map=self.__sockMap, count=1)
; File "C:\Python27\lib\asyncore.py", line 220, in loop
poll_fun(timeout, map)
; File "C:\Python27\lib\asyncore.py", line 156, in poll
read(obj)
; File "C:\Python27\lib\asyncore.py", line 87, in read
obj.handle_error()
; File "C:\Python27\lib\asyncore.py", line 83, in read
obj.handle_read_event()
; File "C:\Python27\lib\asyncore.py", line 449, in handle_read_event
self.handle_read()
; File "C:\Python27\lib\site-packages\pysnmp\carrier\asyncore\dgram\base.py", l
ine 157, in handle_read
self._cbFun(self, transportAddress, incomingMessage)
; File "C:\Python27\lib\site-packages\pysnmp\carrier\base.py", line 68, in _cbF
un
self, transportDomain, transportAddress, incomingMessage
; File "C:\Python27\lib\site-packages\pysnmp\entity\engine.py", line 145, in __
receiveMessageCbFun
self, transportDomain, transportAddress, wholeMsg
; File "C:\Python27\lib\site-packages\pysnmp\proto\rfc3412.py", line 407, in re
ceiveMessage
PDU, maxSizeResponseScopedPDU, stateReference)
; File "C:\Python27\lib\site-packages\pysnmp\entity\rfc3413\cmdrsp.py", line 13
3, in processPdu
(self.__verifyAccess, snmpEngine))
; File "C:\Python27\lib\site-packages\pysnmp\entity\rfc3413\cmdrsp.py", line 31
7, in handleMgmtOperation
(acFun, acCtx)))
; File "C:\Python27\lib\site-packages\pysnmp\smi\instrum.py", line 250, in writ
eVars
return self.flipFlopFsm(self.fsmWriteVar, vars, acInfo)
; File "C:\Python27\lib\site-packages\pysnmp\smi\instrum.py", line 218, in flip
FlopFsm
rval = f(tuple(name), val, idx, acInfo)
; File "c:\users\ashwalh\appdata\local\temp\pip-build-iibrk4\pysnmp\pysnmp\smi
mibs\SNMPv2-SMI.py", line 470, in writeTest
; File "c:\users\ashwalh\appdata\local\temp\pip-build-iibrk4\pysnmp\pysnmp\smi
mibs\SNMPv2-SMI.py", line 570, in writeTest
; File "c:\users\ashwalh\appdata\local\temp\pip-build-iibrk4\pysnmp\pysnmp\smi
mibs\SNMPv2-SMI.py", line 470, in writeTest
; File "C:\projects_node\CompleteDemo\SNMP\SNMP.py", line 87, in writeTest
raise error.ValueConstraintError()
;ValueConstraintError

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