We are attempting to set up an environment where our mainframe hostprograms communicate with Host Initiated Processes through an Alteon load balancing switch. What we experience is an increase in responsetime by about 2 seconds between our host and the HIS servers compared to other environments where we don't have a load balancing setup. We suspect that the Alteon switch is the cause of these delays. Has anyone had any experience in using an Alteon switch to load balance HIS servers?

The Alteon switch is constantly polling the IP-ports which it should load balance. HIS sees this polling as attempts at communication from a host-system and tries to answer but fails to find the corresponding method and class at the host (naturally enough since there is no host system installed at the Alteon switch).

This polling is causing a massive flooding of entries with event-id 759 in the eventlog at the HIS servers :

HISEHPG0002 HIPGen was unable to locate host information for host xxx.xxx.xxx.xxx.  The call fails and no information will be sent to the unknown host system.

xxx.xxx.xxx.xx is the IP-address of the Alteon switch

We tried to define the Alteon switch as a host in HIS but that only changed the error to event-id 804 instead with the following text :

HISETRF0013 TRMFlowControl has failed attempting to acquire class and method names for processing a request from host xxx.xxx.xxx.xx on port yyyy for program name or tranId 

xxx.xxx.xxx.xx is again the IP-address of the Alteon switch and yyyy is the IP-port that is used for communication with our mainframe hostprograms.

We want to find the source of our responstime delays and also in the process hopefully get rid of the eventlog flooding of event-id 759/804 that's taking place. Any help or suggestions would be greatly appreciated :)

We're running Windows 2008 R2 SP1 and HIS 2010 on the HIS Servers both in the load balancing environment and the non balanced environments that we've compared for responstimes. 

Hi,

Are you using SNA or TCPIP to communicate between the Host and HIS ?

Have you already taken Network Traces on the complete path using either Microsoft Network Monitor or Wireshark ?

Have you configured sticky sessions on the Load Balancer ?

If you are using SNA, have you already taken a look at the Compression and Pacing ?

Have you configured a Network Teaming on the HIS Server ?

Is the Mainframe and the HIS Server in the same Network Subnet ?

Best Regards,