Forum Discussion

Mike_Maher's avatar
Mike_Maher
Icon for Nimbostratus rankNimbostratus
May 02, 2013

Standalone ASM and LB_FAILED

So I have standalone ASMs that DO NOT have LTM licensing on them (they sit behind another piece of hardware which is LTM)

 

 

I have Virtual Servers configured with an HTTP Class set as the resource and a pool (with a single node because no LTM on this device) defined within the HTTP Class. The node is actually another LTM, but I have 2 data center so occasionally when maintenance is being performed on one I have to go into the HTTP Class and swith the pool to the other DC. I am trying to find a way to automate this with an iRule, and I thought I had a pretty simple way to do it but it is not working for some reason.

 

 

So if I have the HTTP Class set to go to pool DC1 and then I have the following iRule also attached to the VS, the VS actually shows Green even if DC1 is failing healthcheck, which suggests to me that the iRule is functioning, but it isn't.

 

 

when LB_FAILED {

 

pool DC2_pool

 

}

 

 

I feel like I am missing something simple here, or maybe I am being too simple and I need something a bit more complex, any thoughts would be helpful. This is a long running administrative issue that I would like to solve if possible.

 

 

 

 

 

application delivery
dev
devops
iRules

2 Replies

Sort By
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    May 02, 2013
    Hi Mike,

     

     

    Take a look at the examples in this SOL and let us know if you get stuck:

     

     

    sol10386: Using the LB::reselect iRules command without a limiting mechanism may result in a SYN flood

     

    https://support.f5.com/kb/en-us/solutions/public/10000/300/sol10386.html

     

     

    Aaron
  • Mike_Maher's avatar
    Mike_Maher
    Icon for Nimbostratus rankNimbostratus
    May 03, 2013
    Aaron,

     

    You da man, using the LB::reselect in my iRule fixed the issue, and this is going to resolve a long standing administrative issue we have had here. It is going to save us a lot of after hours work on my team. I owe you dinner or something if you are ever in St. Louis or the next time I am in Seattle.

     

     

    One question regarding the SYN flood issue in the SOL article. So all of my pools only have 1 member since I don't have LTM licensing, would the retry logic cause any issues. Also would I really I need it since I only have one member?

     

     

    Mike