If you have clients using the ECI interface with the CICS Transaction Gateway to communicate with a CICS application running in MSS, a client program might receive an ECI_ERR_TRANSACTION_ABEND return code with an abend code of AZTY, indicating that several clients tried to communicate with the system at the same time but not all requests could be satisfied by MTO. The workaround for this issue is to set the environment variable TX_UNICLI_SESSIONS to the required number of sessions in the Configuration Information for the enterprise server as follows:
[ES-Environment] TX_UNICLI_SESSIONS=<required-number-of-sessions>
The default is 4.
You should set Maximum requests in the Client Section of the CICS Transaction Gateway configuration to the same value.
If you do this you will also probably need to change the client program to ignore the ECI-ERROR_MAX_SESSIONS return code and retry the call. For example:
do
{
Rc = CICS_ExternalCall (&EciParms);
} while (Rc == ECI_ERR_MAX_SESSIONS);
If you do not make this modification, the client program might still receive the ECI_ERR_TRANSACTION_ABEND return code.
Emulation is not available for the DSNTIAUL and DSNUTILB mainframe utilities