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