Warning Handling

Miscellaneous non-critical issues may occur while the Handler is being executed. The Handler will handle such issues by itself, thus no special handling is required for such cases. However, sometimes it's reasonable to be notified about such events. For this reason, the Handler exposes OnixS::ICE::iMpact::MarketData::WarningListener interface and OnixS::ICE::iMpact::MarketData::Handler::registerWarningListener member to be able to subscribe to and handle warnings.

Once instance of OnixS::ICE::iMpact::MarketData::WarningListener is assigned to the Handler, it will invoke OnixS::ICE::iMpact::MarketData::WarningListener::onWarning member each time error occurs. OnixS::ICE::iMpact::MarketData::WarningListener::onWarning member has couple of input parameters which define code (identifier) of warning and human-readable explanation or description of the warning.

OnixS::ICE::iMpact::MarketData::KnownWarnings type contains constants and descriptions for the warnings which may occur while processing market data from Multicast Price Feed.

• Generic This is a general-purpose warning that could be raised for various issues not covered by more specific warnings.
• NoNetworkActivity This warning occurs when the Handler hasn't received any messages or heartbeats for an extended period.
• SessionNumberMismatch Triggered when the session number received from the server differs from the previous session. This might happen after a daily maintenance window, server restart, or any event that causes a new session to start unexpectedly.
• PacketGap Packet gaps occur when there is a missing sequence in packets received from a multicast feed.
• PacketQueueOverflow Signals that the internal queues used by the Handler to store incoming packets are full. Possible reasons include high traffic volumes, insufficient processing speed, or improper queue size configuration in the system.
• ListenerFailure This warning is raised when the Handler catches an exception in the user-space code.
• NoUdsForMarketType There are no UDS available for the requested market type.