ECI to CICS call (ECI_ASYNC) sometimes returns ("ECI_ERR_NO_CICS")   

Hi jsanz,

Yes you will need to configure a CICS Universal Client connection to the TXSeries region.

I would advise that you use ECI_SYNC calls to TXSeries and not ECI_ASYNC. It may not seem obvious, but I have noticed in the past that the CUC is less efficient with ECI_ASYC calls compared to ECI_SYNC calls as the transaction rate increases. The CUC seems to run into threading issues as it tries to submit new requests and hold the responses from earlier calls until the client program makes the ECI_GET_REPLY call. When a client program makes many simultaneous ECI_SYNC calls, the CUC is able to start up threads (based on a CUC setting) and service all the requests without waiting for an individual reply before submitting the next request to CICS.

In one test scenario I did a few years ago, I found that I got significantly better throghput by using ECI_SYNC compared to ECI_ASYNC, so we decided to change the client program - it also has the advantage of being easier to program on the client side as you don't need to make another call to get the response.

Do you always get the ECI_ERR_NO_CICS messages or only on some calls? If the problem is intermittent, try switching to ECI_SYNC. If you always get the error then you probably have a setup problem.

Thanks, Iain