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