To select gateway TP1/Servers at random, specify Y in the DCHOSTSELECT client environment definition.

When a CUP requests service, the CUP inquires the node that has the desired service from the name service of the gateway TP1/Server which is specified in the DCHOST client environment definition.

When multiple gateway TP1/Servers are specified, TP1/Client first inquires of the name service of the gateway TP1/Server that is specified at the beginning. If the service request is not accepted since TP1/Server specified at the beginning is not started or for other reasons, an attempt is made to switch to the next TP1/Server which is specified as the next gateway. This is the only case where a TP1/Server switch is attempted.

TP1/Server distributes the service requests to multiple nodes to distribute the load on the nodes. The schedule service of a node that receives service requests may sometimes transfer the service requests to TP1/Server on a different node to distribute the load. However, if TP1/Client has selected gateway TP1/Servers at random, the service requests are distributed from the already-selected gateway TP1/Server to a different TP1/Server in a different node. This may cause some overhead.

To prevent the above situation, you can distribute the load on the gateway TP1/Server selected by TP1/Client with priority. To distribute the load on the gateway TP1/Server with priority, specify Y in the DCSCDLOADPRIORITY client environment definition.

This definition is valid only when you execute RPCs without using the name service (specify Y in the DCSCDDIRECT client environment definition).

Note

When you distribute the load on the gateway TP1/Server of a node with priority and the gateway TP1/Server stops due to an error, TP1/Client switches the failed gateway TP1/Server to a different gateway TP1/Server. Even if the previous TP1/Server is restarted, TP1/Client uses the current gateway TP1/Server with priority. Therefore, the restarted TP1/Server may not receive as many service requests as before from TP1/Client even though its load is low.

To change the gateway TP1/Server, reexecute the canceling of the authentication of the client user (dc_clt_cltout function or dc_clt_cltout_s function) and the requesting of the authentication of the client user (dc_clt_cltin_s function). By doing so, the restarted TP1/Server may be assigned as the gateway TP1/Server .