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Mark_58017's avatar
Mark_58017
Icon for Nimbostratus rankNimbostratus
Aug 07, 2013

Dynamic Ratio Load Balancing

Hi,

 

We have an API that automatically inserts servers into a load balanced pool. The pool uses dynamic load balancing and the permanent servers in there have WMI monitors which seem to be working well. The issue is the automation doesn't create the node with a WMI monitor hence we have servers sat in the pool with no monitor and servers sat in the pool with monitors.

 

All the servers are up and passing traffic. However, I cannot ascertain what ratio the servers without WMI have been given. Does anyone know on what basis the F5 sends traffic to the non-WMI servers?

 

 

Thanks Mark

 

config
design

1 Reply

  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Aug 07, 2013
    I cannot ascertain what ratio the servers without WMI have been given. i understand it is 1.

    The node is not returning SNMP data in the correct format. If the BIG-IP system cannot interpret the data returned by the SNMP DCA monitor, it sets the weight of the node to 1.sol9125: Overview of Dynamic Ratio load balancing

    http://support.f5.com/kb/en-us/solutions/public/9000/100/sol9125.html

    e.g. 

     200.200.200.101 is linux without wmi agent, 200.200.200.103 is windows 2003 with wmi agent

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm node
ltm node 200.200.200.101 {
    address 200.200.200.101
    monitor mywmi
    session monitor-enabled
    state up
}
ltm node 200.200.200.103 {
    address 200.200.200.103
    dynamic-ratio 113
    monitor mywmi
    session monitor-enabled
    state up
}
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm monitor wmi mywmi
ltm monitor wmi mywmi {
    agent "Mozilla/4.0 (compatible: MSIE 5.0; Windows NT)"
    command "GetCPUInfo, GetDiskInfo, GetOSInfo"
    defaults-from wmi
    interval 5
    method POST
    metrics "LoadPercentage, DiskUsage, PhysicalMemoryUsage:1.5, VirtualMemoryUsage:2.0"
    password password
    post RespFormat=HTML
    time-until-up 0
    timeout 16
    url /scripts/F5Isapi.dll
    username administrator
}
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm node dynamic-ratio
ltm node 200.200.200.101 {
    dynamic-ratio 1
}
ltm node 200.200.200.103 {
    dynamic-ratio 113
}