Troubleshooting sporadic persistence Issues. Best Ways to capture issue


Running Version 7.2.36 on a LB 2600 appliance.  For over 6 months, we have been experiencing issues with persistence failing and am feeling frustrated in troubleshooting this issue. (we've tried super HTTP, source IP, Select Header with TRUE-CLIENT-IP and now am going back to Active Cookie).   We've opened multiple tickets but they've all come down to the fact that I have to capture this issue in debug to get any farther with Kemp support.  Since its sporadic and cannot be re-produced reliably, I cannot just turn on L7 debugging due to the amount of logging data that gets generated.  

Its causing major issues because when it happens while people are in checkout, they get sent back to the login screen. There is nothing hardware wise to point to an issue with the web servers causing the load balancers to switch.   I've pulled network traces on the Virtual Service where we are using Active Cookies and the traces show the cookie is there and the values haven't changed, but it still gets re-directed to another real server mid-session.

Is there any way to forward this L7 logging data to a syslog server?  If I turn on L7 debugging, can it be redirected and not fill up the local log?  One tech recommended using Kemp 360 Central, but I don't see anywhere in the documents where it provides better service than turning on L7 debugging and downloading the files. 

1 comment

Mark Deegan


You can always setup a netconsole host and set this in "System configuration ==> Logging Options ==> System log files ==> debug options" This is a very verbose logging and also a streaming log so it is not kept on the Lm itself.

I would also recommend upgrading to the 7.2.38 firmware as there have been a few fixes since the 7.2.36 firmware was released.