Concurrent or scheduled processes are programs that run in the background. Oracle Enterprise Scheduler Service (ESS) provides us the ability to manage the complete lifecycle of a scheduled process, including development, distribution, scheduling, and monitoring. ESS has been around since 2011, supporting applications such as Oracle Fusion Applications, and has finally been formally bundled with the 12c release of Oracle SOA Suite. It is now called Oracle Enterprise Scheduler, although the short name ESS still sticks.

Enterprise applications require the ability to respond to many real-time transactions requested by online users or web services. They also require the ability to offload larger transactions in order to run at a future time or automate the running of application maintenance work based on a defined schedule. ESS provides the ability to run different job types according to a preconfigured schedule, including Java, PL/SQL, binary scripts, web services, and EJBs distributed across the nodes in an Oracle WebLogic Server cluster. ESS runs these jobs securely with high availability and scalability and provides monitoring and management through Oracle Enterprise Manager Fusion Middleware Control.

In a nutshell, ESS does exactly what it is named after, the scheduling of jobs. These jobs can perform a variety of activities ranging from triggering web services, custom scripts, and packaged code to managing the activation and deactivation of composites and scheduling fault management. For instance, an ESS job can control inbound adapters, wherein polling services could be configured to consume messages on predefined schedules. Furthermore, notifications of faulted instances and subsequent recovery of these faults can also be scheduled through ESS jobs. ESS is not just an administrative module, but a first-class component of Oracle SOA Suite 12c, wherein jobs can also be called from within a BPEL process. Jobs and schedules can be defined from client applications, through a Java API, or through the Fusion Middleware Control user interface.

Additionally, ESS also exposes a web service through which (predefined) jobs can be scheduled. With ESS, jobs can be scheduled, dependencies between jobs can be declared, and services can be turned on and off according to a specific schedule.

This chapter, however, concentrates on introducing ESS to SOA Suite 12c administrators and covers core areas of administration, namely the following:

Discovering the ESS consoles

In order to explore the core administrative functions offered by ESS in Oracle SOA Suite 12c, the base domain needs to be extended with ESS managed server and EM Plugin for ESS. Note that the ESS components can be targeted to an existing managed server or a separate and dedicated ESS managed server. The EM plugin for ESS is, by default, targeted to the Administration Server. Once the domain is created and the server where the ESS extensions are targeted is started, scheduling components can be accessed from the Oracle Enterprise Manager Fusion Middleware Control console. The following screenshot displays the scheduling services components of ESS:

Figure 11.1: Screenshot of the Scheduling Services components with ESSAPP

Alternatively, at any point in time, administrators can use the ESS health check console at http://<host>:<port>/ess to submit an internal job that provides the current status of all ESS servers in the cluster, as shown in the following screenshot:

Figure 11.2: The ESS health check console and server status