Acclaimed Contributor.. FrankMortensen Acclaimed Contributor..
Acclaimed Contributor..
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NNMi - poll frequency when node down

Hi

 

In NNMi 9.11 on Windows, how often is a node poll after it has being detected as down. I am quite sure that it is being polled more often than  what the NNMi Admin has configured under Monitoring Settings, but how often does it happen? Is i a fraction of the time specified under monitoring settings, or is it a fixed interval.

 

Where is this documented, btw? I did not find any info. in the Causal Analysis WP or the Deployment Guide.

 

BR,

Frank

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6 Replies
Absent Member.. DJ Hogeweg Absent Member..
Absent Member..

Re: NNMi - poll frequency when node down

Hi Frank, The Deployment Guide describes the mechanism at NNMi Communication / Network Latency and Timeouts:

 

"For each request retry, NNMi adds the configured timeout value to the previous timeout value. Thus, the pause gets longer between each retry. For example, when NNMi is configured to use timeout of 5 seconds and three retries, NNMi waits 5 seconds for a response to the first request, 10 seconds for a response to the second request, and 15 seconds for a response to the third request before giving up until the next polling cycle."

 

I've tested this for SNMP communications and it behaves like HP describes. But be aware that timeouts are configured at Communication and that the polling interval is configured at monitoring. Regards,

 

DJ

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Acclaimed Contributor.. FrankMortensen Acclaimed Contributor..
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Re: NNMi - poll frequency when node down

Hi DJ

 

Thanks for your answer.

 

I guess I wasn't clear enough in my original posting. Don't worry, it's not you it's me. It has happened before 🙂

 

I was looking for the polling interval that NNMi uses on a node that is currently registered in NNMi as down. The algorithm you quote is what makes NNMi eventually conclude that the node is down in the first place. From this moment on, I *believe* that NNMi polls this node more frequent than the configured polling interval, to make sure that it quickly detects it when the node comes back up. My question is whether it is correct that NNMi behaves like that, and also where this is documented (if it is in actually documented..)

 

BR,

fRank

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Absent Member.. DJ Hogeweg Absent Member..
Absent Member..

Re: NNMi - poll frequency when node down

Hi Frank,

When a node is down you will see (if you use a sniffer) that at the interval defined at monitoring NNMi will try to poll the node. It won't get an answer and it will retry according to the timeout values defined at communication. When it runs out at the number of retries it's allowed to the next polling is your monitoring poll. When your NNMi server isn't busy it's like a swiss watch. Regards,

DJ

Acclaimed Contributor.. FrankMortensen Acclaimed Contributor..
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Re: NNMi - poll frequency when node down

Hm, interesting.

 

And thanks for the update! You seem to be sure of this 🙂

 

My customer has apparently sniffed, and if I understood them correctly, they saw that NNMi was trying to contact the node more often than the defined polling interval. But then I assume that they have witnessed the polling taking place as part of NNMI's retry attempts.

 

Frank

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AndyKemp Acclaimed Contributor.
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Re: NNMi - poll frequency when node down

its not a linear retry, it increments in increasing intervals I remember from working with our NCRE.

Have a nice day 🙂

Andy Kemp
I've lasted longer in the technology industry than most certifications.
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Absent Member.. DJ Hogeweg Absent Member..
Absent Member..

Re: NNMi - poll frequency when node down

Hi Frank,

Had a week off. They might have witnessed a discovery cycle initiated by spiral discovery. This is not postponed by a node down. I'm not sure whether a custom poll will be suppressed by a node down. Regards,

DJ
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