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  1. ZABBIX BUGS AND ISSUES
  2. ZBX-12956

queue calculation may give false positives for not fast *bulk* snmp operations

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    • Icon: Problem report Problem report
    • Resolution: Duplicate
    • Icon: Major Major
    • None
    • 3.4.3
    • None
    • Sprint 20, Sprint 21

      Not a bug , but ...

      Just FYI, I'm using a patch from ZBXNEXT-4103 to let my SNMPv3 device a chance to work in bulk mode. But it's not related to current case.

      But when I use it (bulk really works, with notes), I see an unexpected queue behavior - it's jumping.

      When attempt to capture snmp traffic, I could see that maximal OIDs number my device may reach is close to ~60 and as I was able to figure out - it depends on data size the device should reply by.

      Zabbix nicely splits on 2 parts and repeats requests in the same "snmp session" when it gets "error-status: tooBig".
      That and plus that my device probably not that fast, causes that the whole host polling may take up to 10-20 seconds.
      The host has 1000 items with 60 seconds update interval.

      Internal monitoring: if increase update interval to queue measurement to 3 seconds, we can cleanly see those spikes. See graph.

      Yes, I know that such items polling depends on interfaceID so scheduled time will be the same for all the 1000 items.

      When I have 4 hosts and many pollers - it gets not any better.
      I need to monitor much more such snmp hosts and much more items per host.

      The request is to reconsider such behavior and maybe improve some part (scheduling or queue calculation).

      I have bunch of snmp traffic captures with different number of pollers, 1 or 4 number of hosts, captured from server start and following 3-4 polling batches. Can be provided on request.

        1. queue.png
          queue.png
          54 kB
        2. pollers.png
          pollers.png
          52 kB

            Unassigned Unassigned
            zalex_ua Oleksii Zagorskyi
            Team C
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              Created:
              Updated:
              Resolved: