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