SNMP v3 Engine Discovery is slow for 250 Hosts and CPU is taking 90% when trying using asynio

[ganeshhsbsoft]

Hi,

    For each Host, SNMPEngine object is initialized and it is takes lot of time and CPU due to lot __manageColumns, exportSymbols  activities.

  Is it possible to use one SNMPEngine  object to query all hosts EngineID ? If there other way to query only EngineID from 250+ hosts concurrently ?

Script:

import asyncio
import pysnmp.hlapi.asyncio as snmp
import time
from pysnmp import debug
debug.setLogger(debug.Debug("all", 'dsp', 'msgproc', 'secmod'))

async def get(host, port, user, oid, timeout=5, retries=1):
result = []
try:
snmpEngine = snmp.SnmpEngine()
transportTarget = snmp.UdpTransportTarget((host, port), timeout=timeout, retries= retries)
observerContext = {}
snmpEngine.observer.registerObserver(lambda e, p, v, c: c.update(securityEngineId=v['securityEngineId']), 'rfc3412.prepareDataElements:internal', cbCtx=observerContext)
authData = snmp.UsmUserData(user)

    response = await snmp.getCmd(snmpEngine,
                                 authData,
                                 transportTarget,
                                 snmp.ContextData(),
                                 #snmp.ObjectType(snmp.ObjectIdentity(oid)),
                                 snmp.ObjectType(snmp.ObjectIdentity('1.3.6.1.2.1.1')),
                                 lookupMib=False
                                 )

    errorIndication, errorStatus, errorIndex, varBinds = response

    if errorIndication:                
        print(f'{host}: errorIndication: {errorIndication}')
    elif errorStatus:
        print('{}: {} at {}'.format(host, errorStatus.prettyPrint(), errorIndex and varBinds[int(errorIndex) - 1][0] or '?'))

    if 'securityEngineId' not in observerContext:
        print("Can't discover peer EngineID, errorIndication: %s" % errorIndication)
    else:
        securityEngineId = observerContext.pop('securityEngineId')
        print('Remote securityEngineId = %s' % securityEngineId.prettyPrint())
        result.append(securityEngineId.prettyPrint())

    snmpEngine.transportDispatcher.closeDispatcher()
except Exception as err:
    print (f'Error at SNMP get() due to {err}')
finally:
    print(f'Get {host}, {oid}: {result}')
    return result

async def main():
st = time.time()
tasks = []
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
tasks.append(get('192.168.50.124', 161, "AUTHPRIV", '1.3.6.1.2.1.1.1.0', 5, 1))
print ("Time taken to append ", time.time() - st)
results = list(filter(lambda a: a, await asyncio.gather(*tasks)))
print(f'main() results: {results}')

print ("Time taken to complete ", time.time() - st, len(results))

if name == 'main':
asyncio.run(main())

Thanks in advance,
Ganesh