SLS BOOSTER COMMISSIONING

A number of beam dynamics applications have been developed for the commissioning of the booster synchrotron[4], making ample use of the CORBA application objects provided. During the three months of booster commissioning (July-September 2000), the model server recorded an uptime of 100%. The server processors are administered through the use of UNIX shell scripts which have sufficient modularity and flexibility to enable/disenable single or groups of servers and to understand and account for their inter-dependencies. Server objects, through their use in different client processes, were extensively tested and in some cases revealed certain anomalies in the underlying APIs. A crucial test of the software components presented itself whenever significant hardware problems occurred. The capability with which the message server could react to a multitude of messages was examined. Whilst some hundreds of error messages per second could be handled, the frequency with which error messages were reported was optimized to avoid unnecessary repetition. The situation also permitted a better understanding of the responses from the CDEV API suggesting, in some cases, a more appropriate action to be initiated.

The deployment of several event-based applications placed a stringent examination of the reliability of the MICO Event Service. Limits for the event queue lengths and timeouts were encountered which, in the worst case, would lead to a crash of the event daemon. Whilst such a scenario is easily avoided through a better match of supply and demand of events, a maximum queue length and an improvement to the error exception handling within the event daemon has since been afforded.

In general, following the initial period of implementation, operator intervention was minimal with clients able to interact spontaneously with the many servers and to display their event data. The CORBA objects are to be further tested and optimized through their use in applications currently under development for the commissioning of the SLS storage ring, beginning in January 2001.