(zos)

Workload management (WLM) for z/OS

Workload management optimizes the distribution of incoming work requests to the application servers, enterprise beans, servlets, and other objects that can most effectively process the requests. Workload management also provides failover when servers are not available, improving application availability.

For details on workload management, see z/OS MVS Planning: Workload Management, which is available on the z/OS Internet Library website. We might also find z/OS MVS Programming: Workload Management Services helpful.

When using workload management on z/OS, we can define workload management policies for the application servers. To get started, we do not need to define special classification rules and work qualifiers, but you might want to define them for the production system.

Workload management provides the following benefits to applications that are running on an application server:

• It balances server workloads, allowing processing tasks to be distributed according to the capacities of the different machines in the sysplex.

• It provides failover capability by redirecting client requests if one or more servers is unable to process them. This improves the availability of applications and administrative services.

• It enables systems to be scaled up to serve a higher client load than provided by the basic configuration. With clustering, additional instances of servers, servlets, and other objects can be added to the configuration.

• It enables servers to be transparently maintained and upgraded while applications remain available for users.

• It centralizes the administration of servers and other objects.

In the product environment, you implement workload management by using clusters, transports, and replication domains.

Subtopics

• (zos) Connection optimization
  Characteristics of a configuration in which the Domain Name Server cooperates with workload management (WLM) to route client requests throughout a cell are:

• (zos) Sysplex routing of work requests
  The product uses the domain name server (DNS) to route work requests within a cell. We can use the DNS, instead of a sysplex distributor to distribute workload and balance requests for the same hostname across multiple IP addresses (one per daemon).

• (zos) Address space management for work requests
  The product propagates the performance context of work requests by using workload management (WLM) enclaves. Each transaction has its own enclave and is managed according to its service class.

• (zos) WLM dynamic application environment operator commands
  The dynamic application environments are displayed and controlled separately from static application environments. To control the dynamic environments, set the Resource Access Facility (RACF ) server class profiles to give you the proper permission to issue MVS™ console commands.

Related concepts

Techniques for managing state

Related information:

z/OS Internet Library website