GH-36155: [C++][Go][Java][FlightRPC] Add support for long-running que…

…ries (#36946)

### Rationale for this change

In Flight RPC, FlightInfo includes addresses of workers alongside result partition info. This lets clients fetch data directly from workers, in parallel or even distributed across multiple machines. But this also comes with tradeoffs.

Queries generally don't complete instantly (as much as we would like them to). So where can we put the 'query evaluation time'?

* In `GetFlightInfo`: block and wait for the query to complete.
  * Con: this is a long-running blocking call, which may fail or time out. Then when the client retries, the server has to redo all the work.
  * Con: parts of the result may be ready before others, but the client can't do anything until everything is ready.
* In `DoGet`: return a fixed number of partitions
  * Con: this makes handling worker failures hard. Systems like Trino support fault-tolerant execution by replacing workers at runtime. But GetFlightInfo has already passed, so we can't notify the client of new workers.
  * Con: we have to know or fix the partitioning up front.

Neither solution is optimal.

### What changes are included in this PR?

We can address this by adding a retryable version of `GetFlightInfo`: `PollFlightInfo(FlightDescriptor)`

`PollFlightInfo` returns `PollInfo`:

```proto
message PollInfo {
  // The currently available results so far.
  FlightInfo info = 1;
  // The descriptor the client should use on the next try.
  // If unset, the query is complete.
  FlightDescriptor flight_descriptor = 2;
  // Query progress. Must be in [0.0, 1.0] but need not be
  // monotonic or nondecreasing. If unknown, do not set.
  optional double progress = 3;
  // Expiration time for this request. After this passes, the server
  // might not accept the retry descriptor anymore (and the query may
  // be cancelled). This may be updated on a call to PollFlightInfo.
  google.protobuf.Timestamp expiration_time = 4;
}
```

See the documentation changes for details of them:
http://crossbow.voltrondata.com/pr_docs/36946/format/Flight.html#downloading-data-by-running-a-heavy-query

### Are these changes tested?

Yes.

This has C++, Go and Java implementations and an integration test with them.

### Are there any user-facing changes?

Yes.
* Closes: #36155

Lead-authored-by: Sutou Kouhei <kou@clear-code.com>
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
Co-authored-by: David Li <li.davidm96@gmail.com>
Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>

cpp/src/arrow/flight/CMakeLists.txt

@@ -83,11 +83,15 @@ set(FLIGHT_GENERATED_PROTO_FILES
 
 set(PROTO_DEPENDS ${FLIGHT_PROTO} ${ARROW_PROTOBUF_LIBPROTOBUF} gRPC::grpc_cpp_plugin)
 
+set(FLIGHT_PROTOC_COMMAND ${ARROW_PROTOBUF_PROTOC} "-I${FLIGHT_PROTO_PATH}")
+if(Protobuf_VERSION VERSION_LESS 3.15)
+ list(APPEND FLIGHT_PROTOC_COMMAND "--experimental_allow_proto3_optional")
+endif()
 add_custom_command(OUTPUT ${FLIGHT_GENERATED_PROTO_FILES}
- COMMAND ${ARROW_PROTOBUF_PROTOC} "-I${FLIGHT_PROTO_PATH}"
- "--cpp_out=${CMAKE_CURRENT_BINARY_DIR}" "${FLIGHT_PROTO}"
  DEPENDS ${PROTO_DEPENDS} ARGS
- COMMAND ${ARROW_PROTOBUF_PROTOC} "-I${FLIGHT_PROTO_PATH}"
+ COMMAND ${FLIGHT_PROTOC_COMMAND}
+ "--cpp_out=${CMAKE_CURRENT_BINARY_DIR}" "${FLIGHT_PROTO}"
+ COMMAND ${FLIGHT_PROTOC_COMMAND}
  "--grpc_out=${CMAKE_CURRENT_BINARY_DIR}"
  "--plugin=protoc-gen-grpc=$<TARGET_FILE:gRPC::grpc_cpp_plugin>"
  "${FLIGHT_PROTO}")

cpp/src/arrow/flight/client.cc

@@ -640,6 +640,14 @@ arrow::Future<FlightInfo> FlightClient::GetFlightInfoAsync(
  return future;
 }
 
+arrow::Result<std::unique_ptr<PollInfo>> FlightClient::PollFlightInfo(
+ const FlightCallOptions& options, const FlightDescriptor& descriptor) {
+ std::unique_ptr<PollInfo> info;
+ RETURN_NOT_OK(CheckOpen());
+ RETURN_NOT_OK(transport_->PollFlightInfo(options, descriptor, &info));
+ return info;
+}
+
 arrow::Result<std::unique_ptr<SchemaResult>> FlightClient::GetSchema(
  const FlightCallOptions& options, const FlightDescriptor& descriptor) {
  RETURN_NOT_OK(CheckOpen());

cpp/src/arrow/flight/client.h

@@ -296,6 +296,19 @@ class ARROW_FLIGHT_EXPORT FlightClient {
  return GetFlightInfoAsync({}, descriptor);
  }
 
+ /// \brief Request and poll a long running query
+ /// \param[in] options Per-RPC options
+ /// \param[in] descriptor the dataset request or a descriptor returned by a
+ /// prioir PollFlightInfo call
+ /// \return Arrow result with the PollInfo describing the status of
+ /// the requested query
+ arrow::Result<std::unique_ptr<PollInfo>> PollFlightInfo(
+ const FlightCallOptions& options, const FlightDescriptor& descriptor);
+ arrow::Result<std::unique_ptr<PollInfo>> PollFlightInfo(
+ const FlightDescriptor& descriptor) {
+ return PollFlightInfo({}, descriptor);
+ }
+
  /// \brief Request schema for a single flight, which may be an existing
  /// dataset or a command to be executed
  /// \param[in] options Per-RPC options

cpp/src/arrow/flight/flight_internals_test.cc

@@ -64,9 +64,12 @@ void TestRoundtrip(const std::vector<FlightType>& values,
 
  ASSERT_OK_AND_ASSIGN(std::string serialized, values[i].SerializeToString());
  ASSERT_OK_AND_ASSIGN(auto deserialized, FlightType::Deserialize(serialized));
- if constexpr (std::is_same_v<FlightType, FlightInfo>) {
+ if constexpr (std::is_same_v<FlightType, FlightInfo> ||
+ std::is_same_v<FlightType, PollInfo>) {
+ ARROW_SCOPED_TRACE("Deserialized = ", deserialized->ToString());
  EXPECT_EQ(values[i], *deserialized);
  } else {
+ ARROW_SCOPED_TRACE("Deserialized = ", deserialized.ToString());
  EXPECT_EQ(values[i], deserialized);
  }
 
@@ -255,6 +258,38 @@ TEST(FlightTypes, FlightInfo) {
  ASSERT_NO_FATAL_FAILURE(TestRoundtrip<pb::FlightInfo>(values, reprs));
 }
 
+TEST(FlightTypes, PollInfo) {
+ ASSERT_OK_AND_ASSIGN(auto location, Location::ForGrpcTcp("localhost", 1234));
+ Schema schema({field("ints", int64())});
+ auto desc = FlightDescriptor::Command("foo");
+ auto endpoint = FlightEndpoint{Ticket{"foo"}, {}, std::nullopt};
+ auto info = MakeFlightInfo(schema, desc, {endpoint}, -1, 42, true);
+ // 2023-06-19 03:14:06.004330100
+ // We must use microsecond resolution here for portability.
+ // std::chrono::system_clock::time_point may not provide nanosecond
+ // resolution on some platforms such as Windows.
+ const auto expiration_time_duration =
+ std::chrono::seconds{1687144446} + std::chrono::nanoseconds{4339000};
+ Timestamp expiration_time(
+ std::chrono::duration_cast<Timestamp::duration>(expiration_time_duration));
+ std::vector<PollInfo> values = {
+ PollInfo{std::make_unique<FlightInfo>(info), std::nullopt, std::nullopt,
+ std::nullopt},
+ PollInfo{std::make_unique<FlightInfo>(info), FlightDescriptor::Command("poll"), 0.1,
+ expiration_time},
+ };
+ std::vector<std::string> reprs = {
+ "<PollInfo info=" + info.ToString() +
+ " descriptor=null "
+ "progress=null expiration_time=null>",
+ "<PollInfo info=" + info.ToString() +
+ " descriptor=<FlightDescriptor cmd='poll'> "
+ "progress=0.1 expiration_time=2023-06-19 03:14:06.004339000>",
+ };
+
+ ASSERT_NO_FATAL_FAILURE(TestRoundtrip<pb::PollInfo>(values, reprs));
+}
+
 TEST(FlightTypes, Result) {
  std::vector<Result> values = {
  {Buffer::FromString("")},

cpp/src/arrow/flight/integration_tests/flight_integration_test.cc

@@ -71,6 +71,8 @@ TEST(FlightIntegration, ExpirationTimeRenewFlightEndpoint) {
  ASSERT_OK(RunScenario("expiration_time:renew_flight_endpoint"));
 }
 
+TEST(FlightIntegration, PollFlightInfo) { ASSERT_OK(RunScenario("poll_flight_info")); }
+
 TEST(FlightIntegration, FlightSql) { ASSERT_OK(RunScenario("flight_sql")); }
 
 TEST(FlightIntegration, FlightSqlExtension) {

cpp/src/arrow/flight/integration_tests/test_integration.cc

@@ -708,9 +708,7 @@ class ExpirationTimeCancelFlightInfoScenario : public Scenario {
 
 /// \brief The expiration time scenario - RenewFlightEndpoint.
 ///
-/// This tests that the client can renew a FlightEndpoint and read
-/// data in renewed expiration time even when the original
-/// expiration time is over.
+/// This tests that the client can renew a FlightEndpoint.
 class ExpirationTimeRenewFlightEndpointScenario : public Scenario {
  Status MakeServer(std::unique_ptr<FlightServerBase>* server,
  FlightServerOptions* options) override {
@@ -746,6 +744,77 @@ class ExpirationTimeRenewFlightEndpointScenario : public Scenario {
  }
 };
 
+/// \brief The server used for testing PollFlightInfo().
+class PollFlightInfoServer : public FlightServerBase {
+ public:
+ PollFlightInfoServer() : FlightServerBase() {}
+
+ Status PollFlightInfo(const ServerCallContext& context,
+ const FlightDescriptor& descriptor,
+ std::unique_ptr<PollInfo>* result) override {
+ auto schema = arrow::schema({arrow::field("number", arrow::uint32(), false)});
+ std::vector<FlightEndpoint> endpoints = {
+ FlightEndpoint{{"long-running query"}, {}, std::nullopt}};
+ ARROW_ASSIGN_OR_RAISE(
+ auto info, FlightInfo::Make(*schema, descriptor, endpoints, -1, -1, false));
+ if (descriptor == FlightDescriptor::Command("poll")) {
+ *result = std::make_unique<PollInfo>(std::make_unique<FlightInfo>(std::move(info)),
+ std::nullopt, 1.0, std::nullopt);
+ } else {
+ *result =
+ std::make_unique<PollInfo>(std::make_unique<FlightInfo>(std::move(info)),
+ FlightDescriptor::Command("poll"), 0.1,
+ Timestamp::clock::now() + std::chrono::seconds{10});
+ }
+ return Status::OK();
+ }
+};
+
+/// \brief The PollFlightInfo scenario.
+///
+/// This tests that the client can poll a long-running query.
+class PollFlightInfoScenario : public Scenario {
+ Status MakeServer(std::unique_ptr<FlightServerBase>* server,
+ FlightServerOptions* options) override {
+ *server = std::make_unique<PollFlightInfoServer>();
+ return Status::OK();
+ }
+
+ Status MakeClient(FlightClientOptions* options) override { return Status::OK(); }
+
+ Status RunClient(std::unique_ptr<FlightClient> client) override {
+ ARROW_ASSIGN_OR_RAISE(
+ auto info, client->PollFlightInfo(FlightDescriptor::Command("heavy query")));
+ if (!info->descriptor.has_value()) {
+ return Status::Invalid("Description is missing: ", info->ToString());
+ }
+ if (!info->progress.has_value()) {
+ return Status::Invalid("Progress is missing: ", info->ToString());
+ }
+ if (!(0.0 <= *info->progress && *info->progress <= 1.0)) {
+ return Status::Invalid("Invalid progress: ", info->ToString());
+ }
+ if (!info->expiration_time.has_value()) {
+ return Status::Invalid("Expiration time is missing: ", info->ToString());
+ }
+ ARROW_ASSIGN_OR_RAISE(info, client->PollFlightInfo(*info->descriptor));
+ if (info->descriptor.has_value()) {
+ return Status::Invalid("Retried but not finished yet: ", info->ToString());
+ }
+ if (!info->progress.has_value()) {
+ return Status::Invalid("Progress is missing in finished query: ", info->ToString());
+ }
+ if (fabs(*info->progress - 1.0) > arrow::kDefaultAbsoluteTolerance) {
+ return Status::Invalid("Progress for finished query isn't 1.0: ", info->ToString());
+ }
+ if (info->expiration_time.has_value()) {
+ return Status::Invalid("Expiration time must not be set for finished query: ",
+ info->ToString());
+ }
+ return Status::OK();
+ }
+};
+
 /// \brief Schema to be returned for mocking the statement/prepared statement results.
 ///
 /// Must be the same across all languages.
@@ -1825,6 +1894,9 @@ Status GetScenario(const std::string& scenario_name, std::shared_ptr<Scenario>*
  } else if (scenario_name == "expiration_time:renew_flight_endpoint") {
  *out = std::make_shared<ExpirationTimeRenewFlightEndpointScenario>();
  return Status::OK();
+ } else if (scenario_name == "poll_flight_info") {
+ *out = std::make_shared<PollFlightInfoScenario>();
+ return Status::OK();
  } else if (scenario_name == "flight_sql") {
  *out = std::make_shared<FlightSqlScenario>();
  return Status::OK();

cpp/src/arrow/flight/middleware.h

@@ -57,6 +57,7 @@ enum class FlightMethod : char {
  DoAction = 7,
  ListActions = 8,
  DoExchange = 9,
+ PollFlightInfo = 10,
 };
 
 /// \brief Get a human-readable name for a Flight method.

cpp/src/arrow/flight/serialization_internal.cc

@@ -31,6 +31,26 @@ namespace arrow {
 namespace flight {
 namespace internal {
 
+// Timestamp
+
+Status FromProto(const google::protobuf::Timestamp& pb_timestamp, Timestamp* timestamp) {
+ const auto seconds = std::chrono::seconds{pb_timestamp.seconds()};
+ const auto nanoseconds = std::chrono::nanoseconds{pb_timestamp.nanos()};
+ const auto duration =
+ std::chrono::duration_cast<Timestamp::duration>(seconds + nanoseconds);
+ *timestamp = Timestamp(duration);
+ return Status::OK();
+}
+
+Status ToProto(const Timestamp& timestamp, google::protobuf::Timestamp* pb_timestamp) {
+ const auto since_epoch = timestamp.time_since_epoch();
+ const auto since_epoch_ns =
+ std::chrono::duration_cast<std::chrono::nanoseconds>(since_epoch).count();
+ pb_timestamp->set_seconds(since_epoch_ns / std::nano::den);
+ pb_timestamp->set_nanos(since_epoch_ns % std::nano::den);
+ return Status::OK();
+}
+
 // ActionType
 
 Status FromProto(const pb::ActionType& pb_type, ActionType* type) {
@@ -153,13 +173,9 @@ Status FromProto(const pb::FlightEndpoint& pb_endpoint, FlightEndpoint* endpoint
  RETURN_NOT_OK(FromProto(pb_endpoint.location(i), &endpoint->locations[i]));
  }
  if (pb_endpoint.has_expiration_time()) {
- const auto& pb_expiration_time = pb_endpoint.expiration_time();
- const auto seconds = std::chrono::seconds{pb_expiration_time.seconds()};
- const auto nanoseconds = std::chrono::nanoseconds{pb_expiration_time.nanos()};
- const auto duration =
- std::chrono::duration_cast<Timestamp::duration>(seconds + nanoseconds);
- const Timestamp expiration_time(duration);
- endpoint->expiration_time = expiration_time;
+ Timestamp expiration_time;
+ RETURN_NOT_OK(FromProto(pb_endpoint.expiration_time(), &expiration_time));
+ endpoint->expiration_time = std::move(expiration_time);
  }
  return Status::OK();
 }
@@ -171,13 +187,8 @@ Status ToProto(const FlightEndpoint& endpoint, pb::FlightEndpoint* pb_endpoint)
  RETURN_NOT_OK(ToProto(location, pb_endpoint->add_location()));
  }
  if (endpoint.expiration_time) {
- const auto expiration_time = endpoint.expiration_time.value();
- const auto since_epoch = expiration_time.time_since_epoch();
- const auto since_epoch_ns =
- std::chrono::duration_cast<std::chrono::nanoseconds>(since_epoch).count();
- auto pb_expiration_time = pb_endpoint->mutable_expiration_time();
- pb_expiration_time->set_seconds(since_epoch_ns / std::nano::den);
- pb_expiration_time->set_nanos(since_epoch_ns % std::nano::den);
+ RETURN_NOT_OK(ToProto(endpoint.expiration_time.value(),
+ pb_endpoint->mutable_expiration_time()));
  }
  return Status::OK();
 }
@@ -288,6 +299,47 @@ Status ToProto(const FlightInfo& info, pb::FlightInfo* pb_info) {
  return Status::OK();
 }
 
+// PollInfo
+
+Status FromProto(const pb::PollInfo& pb_info, PollInfo* info) {
+ ARROW_ASSIGN_OR_RAISE(auto flight_info, FromProto(pb_info.info()));
+ info->info = std::make_unique<FlightInfo>(std::move(flight_info));
+ if (pb_info.has_flight_descriptor()) {
+ FlightDescriptor descriptor;
+ RETURN_NOT_OK(FromProto(pb_info.flight_descriptor(), &descriptor));
+ info->descriptor = std::move(descriptor);
+ } else {
+ info->descriptor = std::nullopt;
+ }
+ if (pb_info.has_progress()) {
+ info->progress = pb_info.progress();
+ } else {
+ info->progress = std::nullopt;
+ }
+ if (pb_info.has_expiration_time()) {
+ Timestamp expiration_time;
+ RETURN_NOT_OK(FromProto(pb_info.expiration_time(), &expiration_time));
+ info->expiration_time = std::move(expiration_time);
+ } else {
+ info->expiration_time = std::nullopt;
+ }
+ return Status::OK();
+}
+
+Status ToProto(const PollInfo& info, pb::PollInfo* pb_info) {
+ RETURN_NOT_OK(ToProto(*info.info, pb_info->mutable_info()));
+ if (info.descriptor) {
+ RETURN_NOT_OK(ToProto(*info.descriptor, pb_info->mutable_flight_descriptor()));
+ }
+ if (info.progress) {
+ pb_info->set_progress(info.progress.value());
+ }
+ if (info.expiration_time) {
+ RETURN_NOT_OK(ToProto(*info.expiration_time, pb_info->mutable_expiration_time()));
+ }
+ return Status::OK();
+}
+
 // CancelFlightInfoRequest
 
 Status FromProto(const pb::CancelFlightInfoRequest& pb_request,

cpp/src/arrow/flight/serialization_internal.h

@@ -45,6 +45,7 @@ Status SchemaToString(const Schema& schema, std::string* out);
 
 // These functions depend on protobuf types which are not exported in the Flight DLL.
 
+Status FromProto(const google::protobuf::Timestamp& pb_timestamp, Timestamp* timestamp);
 Status FromProto(const pb::ActionType& pb_type, ActionType* type);
 Status FromProto(const pb::Action& pb_action, Action* action);
 Status FromProto(const pb::Result& pb_result, Result* result);
@@ -60,16 +61,19 @@ Status FromProto(const pb::FlightEndpoint& pb_endpoint, FlightEndpoint* endpoint
 Status FromProto(const pb::RenewFlightEndpointRequest& pb_request,
  RenewFlightEndpointRequest* request);
 arrow::Result<FlightInfo> FromProto(const pb::FlightInfo& pb_info);
+Status FromProto(const pb::PollInfo& pb_info, PollInfo* info);
 Status FromProto(const pb::CancelFlightInfoRequest& pb_request,
  CancelFlightInfoRequest* request);
 Status FromProto(const pb::SchemaResult& pb_result, std::string* result);
 Status FromProto(const pb::BasicAuth& pb_basic_auth, BasicAuth* info);
 
+Status ToProto(const Timestamp& timestamp, google::protobuf::Timestamp* pb_timestamp);
 Status ToProto(const FlightDescriptor& descr, pb::FlightDescriptor* pb_descr);
 Status ToProto(const FlightEndpoint& endpoint, pb::FlightEndpoint* pb_endpoint);
 Status ToProto(const RenewFlightEndpointRequest& request,
  pb::RenewFlightEndpointRequest* pb_request);
 Status ToProto(const FlightInfo& info, pb::FlightInfo* pb_info);
+Status ToProto(const PollInfo& info, pb::PollInfo* pb_info);
 Status ToProto(const CancelFlightInfoRequest& request,
  pb::CancelFlightInfoRequest* pb_request);
 Status ToProto(const ActionType& type, pb::ActionType* pb_type);

cpp/src/arrow/flight/server.cc

@@ -231,6 +231,12 @@ Status FlightServerBase::GetFlightInfo(const ServerCallContext& context,
  return Status::NotImplemented("NYI");
 }
 
+Status FlightServerBase::PollFlightInfo(const ServerCallContext& context,
+ const FlightDescriptor& request,
+ std::unique_ptr<PollInfo>* info) {
+ return Status::NotImplemented("NYI");
+}
+
 Status FlightServerBase::DoGet(const ServerCallContext& context, const Ticket& request,
  std::unique_ptr<FlightDataStream>* data_stream) {
  return Status::NotImplemented("NYI");