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testimony_17780's avatar
testimony_17780
Aug 31, 2018

LATENCY ON VIRTUAL SERVER

Hi Team,

 

I have these as the Latency reading on one of my virtual server on the F5. The values are:- Avg Server(ms) 4,947.46 , Max. Server Latency(ms) 142,787 , Transactions 15,807. I sincerely want to know if these values are normal, if NO ...... (1)What are the causes of this high latency (2) what are the implications such latency will have on the said Virtual Server and the application seating on it, (3)What are the best range of values that the latency should be and finally i want to know what can be done to normalize the latency.

 

application delivery
BIG-IP
LTM

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  • youssef1's avatar
    youssef1
    Icon for Cumulonimbus rankCumulonimbus
    Aug 31, 2018

    Hi,

    Just to be sure that you have latency on your server you can use this irule, it will permit you to target where latency come from:

        when HTTP_REQUEST {
set http_request_time [clock clicks -milliseconds]
}

when HTTP_REQUEST_RELEASE {
set http_request_time_release [clock clicks -milliseconds]
}

when HTTP_RESPONSE {
set http_response_time [ clock clicks -milliseconds ]
}

when HTTP_RESPONSE_RELEASE {
set http_response_time_release [ clock clicks -milliseconds ]
log local0.info "[virtual] Time to match: request: $http_request_time - request_release: $http_request_time_release "
log local0.info "[virtual] Time to match:  response: $http_response_time - request_release: $http_response_time_release"


log local0.info "[virtual] Time to response (request F5 process) = [expr $http_request_time_release - $http_request_time]"
log local0.info "[virtual] Time to response (response F5 process) = [expr $http_response_time_release - $http_response_time]"
}