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  1. OpenNMS
  2. NMS-9238

DnsResolutionMonitor should not use cache for lookups

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      Description

      I followed the docs for DnsResolutionMonitor and run into an issue.

      The service is defined like this:

      <service name="DNS-Resolution-v4" interval="300000" user-defined="true" status="on">
          <parameter key="retry" value="2"/>
          <parameter key="timeout" value="2000"/>
          <parameter key="resolution-type" value="v4"/>
          <parameter key="rrd-repository" value="/usr/share/opennms/share/rrd/response"/>
          <parameter key="rrd-base-name" value="dns-res-v4"/>
          <parameter key="ds-name" value="dns-res-v4"/>
          <parameter key="nameserver" value="8.8.8.8"/>
      </service>
      <monitor service="DNS-Resolution-v4" class-name="org.opennms.netmgt.poller.monitors.DNSResolutionMonitor" />
      

      Scenario:

      Added www.google.com and test.mydomain.com to ONMS (nodeLabels).
      They got an IP from the local network and the DNS-Resolution-v4 service.
      Added poller config, restarted ONMS, both nodes online.

      Now I deleted my A record test.mydomain.com. Instantly nslookup test showed:

      nslookup test.mydomain.com 8.8.8.8
      Server:		8.8.8.8
      Address:	8.8.8.8#53
      
      ** server can't find test.mydomain.com: NXDOMAIN
      

      But the DnsResolutionMonitor didn't go offline after 10-15 minutes. But if I restart ONMS, the poller recognizes the outage.

      The www.google.com node doesn't get any outages (used as reference).

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            • Assignee:
              seth Seth Leger
              Reporter:
              fuhrmann Marcel Fuhrmann
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              • Created:
                Updated:
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