Scheduling
Imixs-Workflow provides a flexible scheduling architecture for automating business processes and system tasks.
Modern business applications often require automated, time-based execution of tasks and processes. This includes periodic jobs like report generation, automated reminders, data synchronization, or escalation handling. The Imixs scheduling system addresses these requirements through a modular and extensible architecture.
Architecture
The Imixs scheduling system follows a service-oriented design pattern where scheduling tasks are implemented through a standardized interface and managed by a central Jakarta EE service. This approach ensures reliability through transaction-safe scheduling operations.
The architecture consists of the Scheduler interface and the SchedulerService. The Scheduler interface, defines how schedulers interact with the system by providing standard configuration attributes, the run() method contract, and enabling consistent scheduler implementations. The SchedulerService acts as the central service, controlling the scheduler lifecycle by creating and managing timers, scheduler configurations, and logging.
SchedulerService
The SchedulerService is built on the Jakarta EE Timer Service (EJB Timer Service), providing enterprise-grade scheduling capabilities.
- Transaction Safety: Timer events are managed within EJB transactions, ensuring data consistency even in failure scenarios
- Persistence: Timer configurations survive server restarts
- Cluster Support: Timer events can be distributed across cluster nodes
- Calendar-Based Scheduling: Sophisticated scheduling patterns using cron-style expressions
- Resource Efficiency: Optimized resource usage compared to managed thread approaches
The service provides a comprehensive infrastructure encompassing configuration management through document-based storage, lifecycle control (start, stop, monitoring), CDI-based implementation handling, detailed logging and error handling, and runtime status monitoring.
WorkflowScheduler
The WorkflowScheduler is the main implementation for handling BPMN-based scheduling. It enables timer-based processing of workitems, automatic reminder and escalation tasks, custom workitem selection via queries, and transaction-safe execution.
