A flight service is an endpoint for retrieving or storing Arrow data. A flight service can expose one or more predefined endpoints that can be accessed using the Arrow Flight Protocol. Additionally, a flight service can expose a set of actions that are available.

from protobuf service arrow.flight.protocol.FlightService

Implements

Constructors

Properties

methods: MethodInfo[] = FlightService.methods

Information for each rpc method of the service, in the order of declaration in the source .proto.

options: JsonOptionsMap = FlightService.options

Contains custom service options from the .proto source in JSON format.

typeName: string = FlightService.typeName

The protobuf type name of the service, including package name if present.

Methods

  • Flight services can support an arbitrary number of simple actions in addition to the possible ListFlights, GetFlightInfo, DoGet, DoPut operations that are potentially available. DoAction allows a flight client to do a specific action against a flight service. An action includes opaque request and response objects that are specific to the type action being undertaken.

    Parameters

    • input: Action
    • Optionaloptions: RpcOptions

    Returns ServerStreamingCall<Action, Result>

    from protobuf rpc: DoAction(arrow.flight.protocol.Action) returns (stream arrow.flight.protocol.Result);

  • Open a bidirectional data channel for a given descriptor. This allows clients to send and receive arbitrary Arrow data and application-specific metadata in a single logical stream. In contrast to DoGet/DoPut, this is more suited for clients offloading computation (rather than storage) to a Flight service.

    Parameters

    • Optionaloptions: RpcOptions

    Returns DuplexStreamingCall<FlightData, FlightData>

    from protobuf rpc: DoExchange(stream arrow.flight.protocol.FlightData) returns (stream arrow.flight.protocol.FlightData);

  • Retrieve a single stream associated with a particular descriptor associated with the referenced ticket. A Flight can be composed of one or more streams where each stream can be retrieved using a separate opaque ticket that the flight service uses for managing a collection of streams.

    Parameters

    • input: Ticket
    • Optionaloptions: RpcOptions

    Returns ServerStreamingCall<Ticket, FlightData>

    from protobuf rpc: DoGet(arrow.flight.protocol.Ticket) returns (stream arrow.flight.protocol.FlightData);

  • Push a stream to the flight service associated with a particular flight stream. This allows a client of a flight service to upload a stream of data. Depending on the particular flight service, a client consumer could be allowed to upload a single stream per descriptor or an unlimited number. In the latter, the service might implement a 'seal' action that can be applied to a descriptor once all streams are uploaded.

    Parameters

    • Optionaloptions: RpcOptions

    Returns DuplexStreamingCall<FlightData, PutResult>

    from protobuf rpc: DoPut(stream arrow.flight.protocol.FlightData) returns (stream arrow.flight.protocol.PutResult);

  • For a given FlightDescriptor, get information about how the flight can be consumed. This is a useful interface if the consumer of the interface already can identify the specific flight to consume. This interface can also allow a consumer to generate a flight stream through a specified descriptor. For example, a flight descriptor might be something that includes a SQL statement or a Pickled Python operation that will be executed. In those cases, the descriptor will not be previously available within the list of available streams provided by ListFlights but will be available for consumption for the duration defined by the specific flight service.

    Parameters

    Returns UnaryCall<FlightDescriptor, FlightInfo>

    from protobuf rpc: GetFlightInfo(arrow.flight.protocol.FlightDescriptor) returns (arrow.flight.protocol.FlightInfo);

  • Get a list of available streams given a particular criteria. Most flight services will expose one or more streams that are readily available for retrieval. This api allows listing the streams available for consumption. A user can also provide a criteria. The criteria can limit the subset of streams that can be listed via this interface. Each flight service allows its own definition of how to consume criteria.

    Parameters

    • input: Criteria
    • Optionaloptions: RpcOptions

    Returns ServerStreamingCall<Criteria, FlightInfo>

    from protobuf rpc: ListFlights(arrow.flight.protocol.Criteria) returns (stream arrow.flight.protocol.FlightInfo);

  • For a given FlightDescriptor, start a query and get information to poll its execution status. This is a useful interface if the query may be a long-running query. The first PollFlightInfo call should return as quickly as possible. (GetFlightInfo doesn't return until the query is complete.)

    A client can consume any available results before the query is completed. See PollInfo.info for details.

    A client can poll the updated query status by calling PollFlightInfo() with PollInfo.flight_descriptor. A server should not respond until the result would be different from last time. That way, the client can "long poll" for updates without constantly making requests. Clients can set a short timeout to avoid blocking calls if desired.

    A client can't use PollInfo.flight_descriptor after PollInfo.expiration_time passes. A server might not accept the retry descriptor anymore and the query may be cancelled.

    A client may use the CancelFlightInfo action with PollInfo.info to cancel the running query.

    Parameters

    Returns UnaryCall<FlightDescriptor, PollInfo>

    from protobuf rpc: PollFlightInfo(arrow.flight.protocol.FlightDescriptor) returns (arrow.flight.protocol.PollInfo);