Inter-node load-balancing facility

OpenTP1 provides a facility for distributing the workload among nodes to prevent RPC requests from becoming concentrated on a specific node. This is called the inter-node load-balancing facility.

To use the inter-node load-balancing facility, the following conditions must be satisfied:

A user server is active that provides the same service to multiple nodes.
Each OpenTP1 node defines the other nodes in the all_node operand in the system common definition and shares information about the user server (name information) that is active in each OpenTP1 node.

This section describes the definitions, processing, and RPC processing related to the use of the inter-node load-balancing facility of OpenTP1 for TP1/Client/J and TP1/Server. Note that the TP1/Client/J facility balances workloads based only on TP1/Server-side determination.

Organization of this subsection: (1) Load balancing based on a TP1/Server determination

The schedule service of TP1/Server distributes the workload to appropriate nodes on the basis of the status of node schedules.

(a) Definitions for TP1/Client/J

Specify dcscddirect=Y in the TP1/Client/J environment definition.

This enables TP1/Client/J to issue a load-balancing request to the schedule service of TP1/Server. In the definitions for TP1/Client/J, specify the OpenTP1 node whose schedule service is to make the determination.

If there are multiple OpenTP1 nodes that can issue a scheduling request, scheduling is requested in the order specified in the dchost operand. To randomly select a TP1/Server that is to issue a scheduling request, instead of following the order specified in the dchost operand, specify dchostselect=Y in the TP1/Client/J environment definition.

(b) Definitions for TP1/Server

In the definitions for TP1/Server, do one of the following:

Specify the following operands in the schedule service definition:
scd_this_node_first = N (default)
scd_announce_server_status = Y (default)
Omit the schedule service definition.

2.2.5 Inter-node load-balancing facility

(1) Load balancing based on a TP1/Server determination

(a) Definitions for TP1/Client/J

(b) Definitions for TP1/Server