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