Absent Member.. priya80 Absent Member..
Absent Member..
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False Node Down Alerts

Dear Experts,

 

Please help me with the following issue that is recurring .

We are receiving frequent Node-Down Alerts like :

============================================================

Critical::xyz.domain.com:
(MS473) xyz may be down. Failed to contact it using ping.

The HP OpenView Operations Self Manager was unable to contact the managed node.
This could be caused by network problems between the management server and the managed node,
a high work load, or a congested network.

============================================================ 

The server team says that server is up and running fine ; The network team says there is no issue at the switch end.

They why do these alerts get generated? Could this be due to some DNS issue(if at all the management server is referring to DNS?

I need to know how to check if the OMW server is referring to DNS for node -name resolution. We see the managed nodes added in the local hostfile but just for cross verification i need to check if the OMW server is refering to DNS... Please help me to find the same.

Also, let me know the possible reasons behind these alert generation.

 

Regards,

Priya

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Pinion Honored Contributor.
Honored Contributor.

Re: False Node Down Alerts

Hi There,

 

In this case the time interval that is configured on the node side (OPC_HBP_INTERVAL_ON_AGENT under [eeagt] namespace) must be equal to the "active" HBP interval configured for the nodes on the server side. The agent will send an ICMP packet after 2/3 of the configured time.

 

If the interval for the ICMP packets sent by the agent is bigger than the interval configured for the active Health Check (e.g. the server actively contacts the agent via HTTPS), the server will initiate an active Health Check cycle. Then ICMP packets from the agent will be received for the same machine between two active cycles.

 

You can set the Health Check time interval on the Server and Agent side to equal values:


1. Health Check time interval on Server side:


- Open OMW MMC Console
- From the drop down menus on the top select Action -> Configure -> Server -> Server Configuration window will open.
- In the Generic Server Configuration tab select namespace Agent Health Check 
- Set the appropriate value for  “Time interval to check agent health (in seconds)”

 

2. Health Check time interval on Agent node side:


- Open a command prompt and execute the below command:
  ovconfchg -ns eaagt -set OPC_HBP_INTERVAL_ON_AGENT  <value>


Kriengsak 

-/\-
Micro Focus Expert
Micro Focus Expert

Re: False Node Down Alerts

Hello Priya,

 

Another reason for this error could be that there is a firewall between the management server and the managed node. A firewall usually doesn't allow ping (ICMP). If that's the case, then you should modify the node in OMW to use the "Agent Only" Heartbeat Polling method.

 

Best regards,

Tobias

 

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IanC2 Absent Member.
Absent Member.

Re: False Node Down Alerts

If this is an intermittent issue then it's probably not firewall related as that'd either work or wouldn't - unless you've got two load balanced firewalls and one of them is set to block ping and the other isn't.

 

If it is intermittent, why not set up a rolling ping logging to a text file and run it for ten minutes/half an hour/whatever and see if you get any dropped pings, or any long responses.  See if those correspond with the false alerts.

 

Are the servers under any duress?  Heavy load or maybe VMs on a contested host?

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