Upgrading from z/OS Connect EE V2

Before you upgrade from z/OS Connect EE V2, ensure that you are aware of the compatibility considerations, file location changes, and behavior differences between z/OS Connect V3 and z/OS Connect EE V2.

IMS, CICS®, and IBM® MQ services are created in the z/OS Connect API toolkit.

The IBM z/OS Connect API toolkit now provides a consistent and integrated service creation experience for the IMS, CICS, and IBM MQ service providers. You must use the API toolkit to create IMS services. IMS Explorer for Development is not compatible with IBM z/OS Connect V3. You cannot connect to a V3 server from IMS Explorer for Development.

IMS services that are created for V3 servers are not compatible with V2 servers.

As a result of the consolidation of service creation, deployment, and management processes in IBM z/OS Connect V3, IMS services that are created for V3 servers are not compatible with V2 servers.

V2 services can run on V3 servers in toleration mode by configuring the IMS mobile service registry on a V3 server to point to the IMS mobile service registry location in V2. No additional configuration is required. You can continue to create APIs to access these services, but these services must run as-is and cannot be changed. If service changes are required, contact IBM Software Support for migration assistance. For more information about configuring the IMS mobile service registry, see IMS mobile services and service registry.

JCL sample files are now in a new location.

Table 1. Sample JCL locations
Location in V2	Location in V3
`<installation_path>`/jcl/baqstrt.jcl	`<hlq>`.SBAQSAMP(BAQSTRT)
`<installation_path>`/jcl/baqs123.jcl	`<hlq>`.SBAQSAMP(BAQS123)
`<installation_path>`/jcl/baqzcbt.jcl	`<hlq>`.SBAQSAMP(BAQZCBT)
`<installation_path>`/jcl/baqls2js.jcl	`<hlq>`.SBAQSAMP(BAQLS2JS)
`<installation_path>`/jcl/baqjs2ls.jcl	`<hlq>`.SBAQSAMP(BAQJS2LS)

Error responses are returned in JSON format by default.

The default value of the useJsonErrorResponses attribute on the zosconnect_zosConnectManager element in the server.xml configuration file is changed to true.

The WOLA service provider returns more HTTP status codes.

The WOLA service provider no longer uses only the HTTP status code 500 Internal Server Error for all error cases. Different HTTP status codes are now used to help distinguish server errors from errors caused by bad input data. The useGenericError attribute of the zosconnect_localAdaptersConnectService element can be set to true to maintain compatibility with previous versions of z/OS Connect.