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