Berliner Elektronenspeicherringgesellschaft für Synchrotronstrahlung mbH (BESSY) CA Gateway Update Ralph Lange, BESSY Ken Evans Jr., APS Jeff Hill, LANL

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond Overview As well CA server as CA client Usually runs on workstation with multiple network interfaces Connects and separates networks in terms of CA connections May use channel aliases (e.g. prefixes) Caches data Keeps connections alive Watchdog mode restarts on core dump

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond CA Proxy Gateway Allows CA between networks – configurable through regular expression filters and CA access security. CA Gateway CA Clients CA Servers

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond CA Proxy Gateway Clients point to one proxy that distributes the data with minimal impact on the private parts. CA Clients CA Servers CA Gateway

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond Caveats The Gateway always introduces a non- scalable bottleneck. A heavily loaded Gateway is a CPU and memory consuming application that usually will add overhead to the system. Bad configuration (too loose) may put more load on the precious side instead of shielding the IOCs.

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond Recent Developments Gateway 2.0 (built against EPICS base ) is complete and working. More bugfixes in the Gateway, GDD, CAS / CAC, important performance improvements. CAput logging feature (same as on IOC). Work on documentation (user manual) started. BUT... –Still some crashes (bad) and brain-dead hang situations (much much worse).  Not yet officially released.

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond Next Steps Mid-July: Jeff and Ken will try to fix the hang problems. After that: Independent of their results a release of the Gateway will be published.  Either a beta release: bad but still better than the old based Gateway. Or a stable 2.0: quite good, but still bad, with lots of room for improvements…

R.Lange, K.Evans, J.Hill: CA Gateway Update – EPICS Meeting Summer Diamond Ideas All the nice ideas for improvements: will be postponed until stable operation of the Gateway is achieved. New hierarchical configuration file format to improve performance (XML format?) New configurable watchdog (steal from Channel Archiver) Better code documentation (using Doxygen?) CMLOG interface Provide some tabular usage and statistics info as web page Use Data Access (new data object) instead of GDD