Application Server

Enhanced Definition

Middleware software that provides a runtime environment for business applications, managing transactions, connections between user interfaces and databases, resource pooling, and application lifecycle. On mainframes, this includes systems like WebSphere Application Server for z/OS. On IBM z/OS, an Application Server is a specialized runtime environment that hosts, manages, and executes business applications, providing services to client programs. It is designed to offer a robust, scalable, and secure platform for transaction processing, data access, and integration, ensuring high availability and integrity for critical enterprise workloads.

Key Characteristics

- Multi-tier architecture supporting web and enterprise applications
- Transaction management and coordination
- Connection pooling for database and resource efficiency
- Load balancing and failover capabilities
- Integration with mainframe transaction processors
- Transaction Management: ACID properties, two-phase commit, distributed transactions
- Connection Pooling: Database connection reuse and management
- Security Services: Authentication, authorization, encryption
- Naming Services: JNDI for resource lookup and binding
- Messaging Services: JMS for asynchronous communication
Mainframe-Specific Features:
- Integration with CICS and IMS transactions
- Access to DB2 and other mainframe databases
- Support for COBOL and PL/I business logic
- High availability through Sysplex coupling
- Workload management integration

Use Cases

- Web-enabling legacy mainframe applications
- Building modern APIs for mainframe services
- Implementing microservices architectures
- Supporting mobile application backends
- Enterprise application integration