lidavidm commented on code in PR #12847: URL: https://github.com/apache/arrow/pull/12847#discussion_r848788087
########## docs/source/java/flight.rst: ########## @@ -0,0 +1,213 @@ +.. Licensed to the Apache Software Foundation (ASF) under one +.. or more contributor license agreements. See the NOTICE file +.. distributed with this work for additional information +.. regarding copyright ownership. The ASF licenses this file +.. to you under the Apache License, Version 2.0 (the +.. "License"); you may not use this file except in compliance +.. with the License. You may obtain a copy of the License at + +.. http://www.apache.org/licenses/LICENSE-2.0 + +.. Unless required by applicable law or agreed to in writing, +.. software distributed under the License is distributed on an +.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +.. KIND, either express or implied. See the License for the +.. specific language governing permissions and limitations +.. under the License. + +================ +Arrow Flight RPC +================ + +Arrow Flight is an RPC framework for efficient transfer of Arrow data +over the network. + +.. contents:: + +.. seealso:: + + :doc:`Flight protocol documentation <../format/Flight>` + Documentation of the Flight protocol, including how to use + Flight conceptually. + + `Java Cookbook <https://arrow.apache.org/cookbook/java/flight.html>`_ + Recipes for using Arrow Flight in Java. + +Writing a Flight Service +======================== + +Flight servers implement the `FlightProducer`_ interface. For convenience, +they can subclass `NoOpFlightProducer`_ instead, which offers default +implementations of all the RPC methods. + +.. code-block:: Java + + public class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + +Each RPC method always takes a ``CallContext`` for common parameters. To indicate +failure, pass an exception to the "listener" if present, or else raise an +exception. + +.. code-block:: Java + + // Server + @Override + public void listFlights(CallContext context, Criteria criteria, StreamListener<FlightInfo> listener) { + // ... + listener.onError( + CallStatus.UNAUTHENTICATED.withDescription( + "Custom UNAUTHENTICATED description message.").toRuntimeException()); + // ... + } + + // Client + try{ + Iterable<FlightInfo> flightInfosBefore = flightClient.listFlights(Criteria.ALL); + // ... + } catch (FlightRuntimeException e){ + // Catch UNAUTHENTICATED exception + } + +To start a server, create a `Location`_ to specify where to listen, and then create +a `FlightServer`_ with an instance of a producer. This will start the server, but +won't block the rest of the program. Call ``FlightServer.awaitTermination`` +to block until the server stops. + +.. code-block:: Java + + class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + + Location location = Location.forGrpcInsecure("0.0.0.0", 0); + try( + BufferAllocator allocator = new RootAllocator(); + FlightServer server = FlightServer.builder( + allocator, + location, + new TutorialFlightProducer() + ).build(); + ){ + server.start(); + System.out.println("Server listening on port " + server.getPort()); + server.awaitTermination(); + } catch (Exception e) { + e.printStackTrace(); + } + +.. code-block:: shell + + Server listening on port 58104 + +Using the Flight Client +======================= + +To connect to a Flight service, create a `FlightClient`_ with a location. + +.. code-block:: Java + + Location location = Location.forGrpcInsecure("0.0.0.0", 58104); + + try(BufferAllocator allocator = new RootAllocator(); + FlightClient client = FlightClient.builder(allocator, location).build()){ + // ... Consume operations exposed by Flight server + } catch (Exception e) { + e.printStackTrace(); + } + +Cancellation and Timeouts +========================= + +When making a call, clients can optionally provide `CallOptions`. This allows +clients to set a timeout on calls. Also, some objects returned by client RPC calls +expose a cancel method which allows terminating a call early. + +.. code-block:: Java + + Location location = Location.forGrpcInsecure("0.0.0.0", 58609); + + try(BufferAllocator allocator = new RootAllocator(); + FlightClient tutorialFlightClient = FlightClient.builder(allocator, location).build()){ + + Iterator<Result> resultIterator = tutorialFlightClient.doAction( + new Action("test-timeout"), + CallOptions.timeout(2, TimeUnit.SECONDS) + ); + } catch (Exception e) { + e.printStackTrace(); + } + +On the server side, timeouts are transparent. For cancellation, the server needs to manually poll +``setOnCancelHandler`` or ``isCancelled`` to check if the client has cancelled the call, +and if so, break out of any processing the server is currently doing. + +.. code-block:: Java + + // Client + Location location = Location.forGrpcInsecure("0.0.0.0", 58609); + try(BufferAllocator allocator = new RootAllocator(); + FlightClient tutorialFlightClient = FlightClient.builder(allocator, location).build()){ + try(FlightStream flightStream = flightClient.getStream(new Ticket(new byte[]{}))) { + // ... + flightStream.cancel("tutorial-cancel", new Exception("Testing cancellation option!")); + } + } catch (Exception e) { + e.printStackTrace(); + } + // Server + @Override + public void getStream(CallContext context, Ticket ticket, ServerStreamListener listener) { + // ... + listener.setOnCancelHandler(()->{ + // Implement logic to handle cancellation option + }); + } + +Enabling TLS +============ + +TLS can be enabled when setting up a server by providing a +certificate and key pair to ``FlightServer.Builder.useTls``. + +On the client side, use ``Location.forGrpcTls`` to create the Location for the client. + +Enabling Authentication +======================= + +.. warning:: Authentication is insecure without enabling TLS. + +Handshake-based authentication can be enabled by implementing +Handlers on the client and server side (i.e.: ``ServerAuthHandler``). +There are two options available user/password and token. Review Comment: Both user/password and token authentication are separate - IMO let's not talk about them here, there's some work needed to document all the auth methods available in Flight and explain why you might need to use each, and I don't want to make this confusing. ########## docs/source/java/flight.rst: ########## @@ -0,0 +1,213 @@ +.. Licensed to the Apache Software Foundation (ASF) under one +.. or more contributor license agreements. See the NOTICE file +.. distributed with this work for additional information +.. regarding copyright ownership. The ASF licenses this file +.. to you under the Apache License, Version 2.0 (the +.. "License"); you may not use this file except in compliance +.. with the License. You may obtain a copy of the License at + +.. http://www.apache.org/licenses/LICENSE-2.0 + +.. Unless required by applicable law or agreed to in writing, +.. software distributed under the License is distributed on an +.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +.. KIND, either express or implied. See the License for the +.. specific language governing permissions and limitations +.. under the License. + +================ +Arrow Flight RPC +================ + +Arrow Flight is an RPC framework for efficient transfer of Arrow data +over the network. + +.. contents:: + +.. seealso:: + + :doc:`Flight protocol documentation <../format/Flight>` + Documentation of the Flight protocol, including how to use + Flight conceptually. + + `Java Cookbook <https://arrow.apache.org/cookbook/java/flight.html>`_ + Recipes for using Arrow Flight in Java. + +Writing a Flight Service +======================== + +Flight servers implement the `FlightProducer`_ interface. For convenience, +they can subclass `NoOpFlightProducer`_ instead, which offers default +implementations of all the RPC methods. + +.. code-block:: Java + + public class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + +Each RPC method always takes a ``CallContext`` for common parameters. To indicate +failure, pass an exception to the "listener" if present, or else raise an +exception. + +.. code-block:: Java + + // Server + @Override + public void listFlights(CallContext context, Criteria criteria, StreamListener<FlightInfo> listener) { + // ... + listener.onError( + CallStatus.UNAUTHENTICATED.withDescription( + "Custom UNAUTHENTICATED description message.").toRuntimeException()); + // ... + } + + // Client + try{ + Iterable<FlightInfo> flightInfosBefore = flightClient.listFlights(Criteria.ALL); + // ... + } catch (FlightRuntimeException e){ + // Catch UNAUTHENTICATED exception + } + +To start a server, create a `Location`_ to specify where to listen, and then create +a `FlightServer`_ with an instance of a producer. This will start the server, but +won't block the rest of the program. Call ``FlightServer.awaitTermination`` +to block until the server stops. + +.. code-block:: Java + + class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + + Location location = Location.forGrpcInsecure("0.0.0.0", 0); + try( + BufferAllocator allocator = new RootAllocator(); + FlightServer server = FlightServer.builder( + allocator, + location, + new TutorialFlightProducer() + ).build(); + ){ + server.start(); + System.out.println("Server listening on port " + server.getPort()); + server.awaitTermination(); + } catch (Exception e) { + e.printStackTrace(); + } + +.. code-block:: shell + + Server listening on port 58104 + +Using the Flight Client +======================= + +To connect to a Flight service, create a `FlightClient`_ with a location. + +.. code-block:: Java + + Location location = Location.forGrpcInsecure("0.0.0.0", 58104); + + try(BufferAllocator allocator = new RootAllocator(); + FlightClient client = FlightClient.builder(allocator, location).build()){ + // ... Consume operations exposed by Flight server + } catch (Exception e) { + e.printStackTrace(); + } + +Cancellation and Timeouts +========================= + +When making a call, clients can optionally provide `CallOptions`. This allows +clients to set a timeout on calls. Also, some objects returned by client RPC calls +expose a cancel method which allows terminating a call early. + +.. code-block:: Java + + Location location = Location.forGrpcInsecure("0.0.0.0", 58609); + + try(BufferAllocator allocator = new RootAllocator(); + FlightClient tutorialFlightClient = FlightClient.builder(allocator, location).build()){ + + Iterator<Result> resultIterator = tutorialFlightClient.doAction( + new Action("test-timeout"), + CallOptions.timeout(2, TimeUnit.SECONDS) + ); + } catch (Exception e) { + e.printStackTrace(); + } + +On the server side, timeouts are transparent. For cancellation, the server needs to manually poll +``setOnCancelHandler`` or ``isCancelled`` to check if the client has cancelled the call, +and if so, break out of any processing the server is currently doing. + +.. code-block:: Java + + // Client + Location location = Location.forGrpcInsecure("0.0.0.0", 58609); + try(BufferAllocator allocator = new RootAllocator(); + FlightClient tutorialFlightClient = FlightClient.builder(allocator, location).build()){ + try(FlightStream flightStream = flightClient.getStream(new Ticket(new byte[]{}))) { + // ... + flightStream.cancel("tutorial-cancel", new Exception("Testing cancellation option!")); + } + } catch (Exception e) { + e.printStackTrace(); + } + // Server + @Override + public void getStream(CallContext context, Ticket ticket, ServerStreamListener listener) { + // ... + listener.setOnCancelHandler(()->{ + // Implement logic to handle cancellation option + }); + } + +Enabling TLS +============ + +TLS can be enabled when setting up a server by providing a +certificate and key pair to ``FlightServer.Builder.useTls``. + +On the client side, use ``Location.forGrpcTls`` to create the Location for the client. + +Enabling Authentication +======================= + +.. warning:: Authentication is insecure without enabling TLS. + +Handshake-based authentication can be enabled by implementing +Handlers on the client and server side (i.e.: ``ServerAuthHandler``). +There are two options available user/password and token. + +Authentication consists of two parts: on +initial client connection, the server and client authentication +implementations can perform any negotiation needed; then, on each RPC +thereafter, the client provides a token. The client set an ID result +of user/password through ``CallHeaders`` / ``Metadata`` these IDs is +recovered by the server side to do validation. The server authentication +handler validates the token and provides the identity of the +client. This identity can be obtained from the +``CallContext.peerIdentity``. + Review Comment: As evidence of what I mean, this is mixing up how different authentication schemes work. Again, the other PR already explains the basic, handshake-based authentication - let's stick to just explaining that instead of trying to explain all three schemes at once. ########## docs/source/java/flight.rst: ########## @@ -0,0 +1,213 @@ +.. Licensed to the Apache Software Foundation (ASF) under one +.. or more contributor license agreements. See the NOTICE file +.. distributed with this work for additional information +.. regarding copyright ownership. The ASF licenses this file +.. to you under the Apache License, Version 2.0 (the +.. "License"); you may not use this file except in compliance +.. with the License. You may obtain a copy of the License at + +.. http://www.apache.org/licenses/LICENSE-2.0 + +.. Unless required by applicable law or agreed to in writing, +.. software distributed under the License is distributed on an +.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +.. KIND, either express or implied. See the License for the +.. specific language governing permissions and limitations +.. under the License. + +================ +Arrow Flight RPC +================ + +Arrow Flight is an RPC framework for efficient transfer of Arrow data +over the network. + +.. contents:: + +.. seealso:: + + :doc:`Flight protocol documentation <../format/Flight>` + Documentation of the Flight protocol, including how to use + Flight conceptually. + + `Java Cookbook <https://arrow.apache.org/cookbook/java/flight.html>`_ + Recipes for using Arrow Flight in Java. + +Writing a Flight Service +======================== + +Flight servers implement the `FlightProducer`_ interface. For convenience, +they can subclass `NoOpFlightProducer`_ instead, which offers default +implementations of all the RPC methods. + +.. code-block:: Java + + public class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + +Each RPC method always takes a ``CallContext`` for common parameters. To indicate +failure, pass an exception to the "listener" if present, or else raise an +exception. + +.. code-block:: Java + + // Server + @Override + public void listFlights(CallContext context, Criteria criteria, StreamListener<FlightInfo> listener) { + // ... + listener.onError( + CallStatus.UNAUTHENTICATED.withDescription( + "Custom UNAUTHENTICATED description message.").toRuntimeException()); + // ... + } + + // Client + try{ + Iterable<FlightInfo> flightInfosBefore = flightClient.listFlights(Criteria.ALL); + // ... + } catch (FlightRuntimeException e){ + // Catch UNAUTHENTICATED exception + } + +To start a server, create a `Location`_ to specify where to listen, and then create +a `FlightServer`_ with an instance of a producer. This will start the server, but +won't block the rest of the program. Call ``FlightServer.awaitTermination`` +to block until the server stops. + +.. code-block:: Java + + class TutorialFlightProducer implements FlightProducer { + @Override + // Override methods or use NoOpFlightProducer for only methods needed + } + + Location location = Location.forGrpcInsecure("0.0.0.0", 0); + try( + BufferAllocator allocator = new RootAllocator(); + FlightServer server = FlightServer.builder( + allocator, + location, + new TutorialFlightProducer() + ).build(); + ){ + server.start(); + System.out.println("Server listening on port " + server.getPort()); + server.awaitTermination(); + } catch (Exception e) { + e.printStackTrace(); + } + +.. code-block:: shell + + Server listening on port 58104 + +Using the Flight Client +======================= + +To connect to a Flight service, create a `FlightClient`_ with a location. + +.. code-block:: Java + + Location location = Location.forGrpcInsecure("0.0.0.0", 58104); + + try(BufferAllocator allocator = new RootAllocator(); + FlightClient client = FlightClient.builder(allocator, location).build()){ + // ... Consume operations exposed by Flight server + } catch (Exception e) { + e.printStackTrace(); + } + +Cancellation and Timeouts +========================= + +When making a call, clients can optionally provide `CallOptions`. This allows Review Comment: ```suggestion When making a call, clients can optionally provide ``CallOptions``. This allows ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
