Web Dispatcher Load balancing session stickyness

[Former Member]

Hi Experts,

I ran into this intermittent problem where while accessing a URL from ABAP system that has 2 application servers and SSL implemented, its throwing

500 SAP Internal Server Error

ERROR: A request for server appserver-01 was sent to server appserver-02. Note 1364846 (termination: ERROR_MESSAGE_STATE)

I added the profile wdisp/HTTPS/sticky_mask = 255.255.255.0 but that didnot help either.

This one web dispatcher setup is for multiple SAP systems. Please suggest.

Thanks

Pankaj

[eduardo_jarauta]

Hi

I'm having same error?

Did you find a solution?

Kind Regards

Eduardo

[bxiv]

Did this happen before you added?

wdisp/HTTPS/sticky_mask

The bit mask that you supplied groups 254 IPs to always use the app server that is first accessed; if bad coding took place or some kind of other odd thing occurs that pulls up the other app server name instead of the virtual names, this could explain the problem.

Sticky via bit masks are more useful for public Internet hosting, if you think of it as a buffer to balance requests to your DMZ systems, but this is my opinion.

Have you also tried levering wireshark on the process to determine what is triggering the mis-balance?

[Former Member]

Is there another reverse proxy, application gateway, etc. in front of the Web Dispatcher? Is the Web Dispatcher connecting directly to the application servers meaning there is nothing in between the application servers and the Web Dispatcher? Was one of application servers shutdown at the time or running low on resources? What is your Web Dispatcher version including patch level? What about your SAP_BASIS version and SP level? What about your kernel version and patch level?

[Former Member]

Glad to see your responce Samuli

We have F5 infront of WD. So when the user makes a call it first goes to F5 --> WD and finally WD sends it application servers. I checked the note# 1364846 but this only talks about checking the network settings. If you look at the error, the response is going from one application server to another which means the problem happening after the F5 and between WD and the application servers.

WD is 7.4 and patch level 12. None of the application server is down.

[Former Member]

Try to reproduce the problem by accessing WD directly. If you are unable to, the problem is with F5. Make sure the F5 passes the client address to WD.