How do you integrate CICS socket applications with other platforms and protocols?

1 Choose a socket model

CICS supports two socket models: the native socket interface and the EZASOKET interface. The native socket interface is more flexible and powerful, but also more complex and low-level. It requires you to write your own socket code in C, C++, or assembler. The EZASOKET interface is simpler and higher-level, but also more limited and less efficient. It allows you to use sockets in COBOL, PL/I, or assembler without writing any socket code. You should choose the socket model that best suits your application requirements, skills, and resources.

2 Configure CICS parameters

To enable CICS socket applications, you need to set some CICS parameters that control the TCP/IP environment, the socket resources, and the security options. For example, you need to specify the TCPIPSERVICE parameter to define the TCP/IP service name and port number for your application. You also need to define a SOCKET or EZASOCKET resource in the CICS resource definition file (RDO) to associate your application with the TCP/IP service. Additionally, you need to set the SEC=YES parameter to enable SSL/TLS encryption and authentication for your socket connections.

3 Handle socket errors

CICS socket applications can encounter various errors during network communication, such as connection failures, timeouts, or data corruption. You need to handle these errors gracefully and avoid causing CICS abends or system failures. You can use the CICS-provided error codes and messages to identify and diagnose the socket errors. You can also use the CICS trace and dump facilities to debug your socket applications. Moreover, you need to implement error recovery and retry logic in your application code to handle transient or recoverable errors.

4 Use standard or custom protocols

CICS socket applications can use standard or custom protocols to exchange data with other systems. Standard protocols are predefined and widely used formats and rules for data communication, such as HTTP, FTP, or SOAP. Custom protocols are user-defined and specific to your application needs, such as binary or text-based formats. You should use standard protocols whenever possible, as they are more interoperable, reliable, and secure. However, if you need to use custom protocols, you should follow some best practices, such as using a common character set, defining a message header and footer, and validating the data.

5 Optimize socket performance

CICS socket applications can have a major influence on the performance of your CICS region and network, so it is important to optimize them to reduce overhead and maximize throughput. Techniques such as reusing socket connections instead of frequently opening and closing them, using non-blocking or asynchronous sockets to avoid waiting for network events, selectively using compression or encryption to reduce data size or enhance security, tuning TCP/IP parameters and buffers to optimize network performance, and monitoring and measuring socket activity and resource usage can all help.

6 Test and deploy socket applications

Before you deploy your CICS socket applications to production, you should test them thoroughly in a realistic environment. You should use tools and methods that simulate the network conditions, the workload, and the behavior of the other systems. You should also verify the functionality, performance, reliability, and security of your socket applications. Furthermore, you should follow the CICS deployment guidelines and procedures to install, activate, and manage your socket applications in production. You should also document your socket applications and their dependencies and configurations.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?