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tm500_165564's avatar
tm500_165564
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Jun 05, 2015

Help with URI string-based session persistence

Hi all Warning: Newer to F5 but really enjoying the experience so far. Trying to get my hands dirty with iRules. I've been doing a lot of research on the forums and I haven't come across the "gol...
application delivery
devops
iRules
LTM
  • nitass's avatar
    nitass
    Jun 11, 2015

    If this happens the LB just sends the request to the same node that the TCP session is tied to - but the iRule still logs as seeing the new strID value. I was confused and expected this to create a new persistence record and load balance the request, but something tells me I would need more logic in my iRule to detach the connection and re-load balance it with a new persistence record.

     

    you can use oneconnect profile. it will do that for you.

     

tm500_165564's avatar
tm500_165564
Icon for Nimbostratus rankNimbostratus
Jun 08, 2015

Just wanted to update that I discovered where my confusion lied: I was seeing persist records drop out of the persist table and not be re-added because my TCP sessions were still active when I was sending follow up HTTP Requests. So long as I opened a new browser window, it would then create a new persist record due to a new TCP connection.

 

I tested and verified that two source IPs will get stuck to the same node when a persist record exists for a given strID value. So I realized where my testing was invalid, and this seems to be acting as I would expect now!

 

The only potential use case that I will need to look into to verify it isn't needed is where a request for a different strID value comes in on the same TCP session. If this happens the LB just sends the request to the same node that the TCP session is tied to - but the iRule still logs as seeing the new strID value. I was confused and expected this to create a new persistence record and load balance the request, but something tells me I would need more logic in my iRule to detach the connection and re-load balance it with a new persistence record.

 

I'm not sure the above situation needed, so I am going back to our development staff for further clarification on how the requests are coming into the VIP with the application.

 

Thank you again for your help!