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sathish_126179's avatar
sathish_126179
Icon for Nimbostratus rankNimbostratus
Mar 17, 2014

Query related to health monitor

Hi,

 

I have a query related to F5 LTM health monitors and require your assistance. Here is the scenario:

 

For example a virtual server for website is configured with health monitor for every 3 minutes (ideally this should be in seconds). Let us assume at 10.10 AM there are 100 connections to a web server and health monitor did a check and noticed node1 was in healthy state at 10.10 AM. What would happen to all connections on node1 when the LB <–> server connectivity goes down for 30 secs between 10:11:00 – 10:11:30 AM ? 1) Would the end users have to refresh the page manually? 2) If a page was loading would they get a page cannot displayed or a partial page? 3) Would all the connections on node 1 be transferred to node 2 automatically? If yes, how would that happen?

 

design

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  • hari_126827's avatar
    hari_126827
    Icon for Cirrus rankCirrus
    Mar 17, 2014

    Hi Sathish,

     

    End users will face disconnection between 10:11:00 – 10:11:30 AM (for new connections if load balanced on faulty node + existing connections only when keepalive or active content is being sent)

     

    For existing connections, it depends if the clients will try to resend the service request on the same node or not will depend on few factors (in sequence): a) Any special profiles like Persistence or OneConnect (HTTP) Profile, e.g.,if there is any persistence profile like source address, then request will come to the same node up to (Persistent session time out - 180 seconds) b) Load balancing Methods + Priority Group Activation

     

    So answer will be as follows: 1. depends on keep-alive option or any active HTTP content being used for Virtual Service. 2 & 3. if the page reloads, then the client will try to reconnect with new connection which depends on a or b options.

     

    KRgds,Hari