elektron refinitiv-realtime eta-api elektron-sdk rrt elektron-transport-api java rssl c++ rcc-api connection source-directory symbology trep batch api fields c ssl log-in reactor Service eikon rdm ETA token market-feed rics ADS callback status market-by-price DACS elektron-data-dictionary consumer linux non-interactive-provider ipa snapshot-pricing rdf conflation chain-ric enum stream-id open-source error service discovery service-name message events multi-threading commodities mrn time-stamp fanout contributions monitoring stale failover aws OMM elektron-direct-feed build equities unsubscribe constituents exchanges volume pricing stress-test service-dictionary tick-history-rest-api data-model rfa refresh-message subscription api-limits rcc service-id sink-driven-source trade dispatch documentation sequence quote search encoding docker load-balancing performance compile ADH 64-bit