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Tim_Sil_178134's avatar
Tim_Sil_178134
Icon for Nimbostratus rankNimbostratus
Dec 10, 2014

Is there a way to see which part of the monitor failed?

This morning we had our website suffer a temporary outage. We have three nodes for the pool and all three were marked down several times over the course of a two minute period, bringing the whole pool and our website down.

 

We have been unable to determine a root cause for this outage. Other pools within the same infrastructure were unaffected so we don't think it is related to storage, the database, or anything else we can determine.

 

Is there a way to determine which part of a monitor is failing in F5? We have the monitor setup to send a request and look for a specific value in the response. Is there a way to know if it is unable to connect at all or if it simply isnt receiving the receive string back? Or is there any other way of getting more detailed information back from the failing monitors?

 

application delivery
availability
devops
iRules
LTM
management

1 Reply

  • gsharri's avatar
    gsharri
    Icon for Altostratus rankAltostratus
    Dec 10, 2014

    By default LTM logs nothing related to a monitors request/response. Beginning with v11.4.0 or maybe v11.5.0 you can enable monitor logging in the properties of a pool member. Monitor activity is then logged to /var/log/monitors/.

     

    Also try using telnet or curl from the LTM cli and make the same request the monitor is making to the pool member so you can see exactly what the response contains.

     

    Tcpdump can also be used to capture and examine monitor traffic.