risingwave_compute/rpc/service/
stream_exchange_service.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::net::SocketAddr;
16use std::sync::Arc;
17
18use either::Either;
19use futures::{Stream, StreamExt, TryStreamExt, pin_mut};
20use futures_async_stream::try_stream;
21use risingwave_pb::id::FragmentId;
22use risingwave_pb::task_service::stream_exchange_service_server::StreamExchangeService;
23use risingwave_pb::task_service::{GetStreamRequest, GetStreamResponse, PbPermits, permits};
24use risingwave_stream::executor::DispatcherMessageBatch;
25use risingwave_stream::executor::exchange::permit::{MessageWithPermits, Receiver};
26use risingwave_stream::task::LocalStreamManager;
27use tonic::{Request, Response, Status, Streaming};
28
29pub mod metrics;
30pub use metrics::{GLOBAL_STREAM_EXCHANGE_SERVICE_METRICS, StreamExchangeServiceMetrics};
31
32pub type StreamDataStream = impl Stream<Item = std::result::Result<GetStreamResponse, Status>>;
33
34#[derive(Clone)]
35pub struct StreamExchangeServiceImpl {
36    stream_mgr: LocalStreamManager,
37    metrics: Arc<StreamExchangeServiceMetrics>,
38}
39
40#[async_trait::async_trait]
41impl StreamExchangeService for StreamExchangeServiceImpl {
42    type GetStreamStream = StreamDataStream;
43
44    #[define_opaque(StreamDataStream)]
45    async fn get_stream(
46        &self,
47        request: Request<Streaming<GetStreamRequest>>,
48    ) -> std::result::Result<Response<Self::GetStreamStream>, Status> {
49        use risingwave_pb::task_service::get_stream_request::*;
50
51        let peer_addr = request
52            .remote_addr()
53            .ok_or_else(|| Status::unavailable("get_stream connection unestablished"))?;
54
55        let mut request_stream: Streaming<GetStreamRequest> = request.into_inner();
56
57        // Extract the first `Get` request from the stream.
58        let Get {
59            up_actor_id,
60            down_actor_id,
61            up_fragment_id,
62            down_fragment_id,
63            database_id,
64            term_id,
65        } = {
66            let req = request_stream
67                .next()
68                .await
69                .ok_or_else(|| Status::invalid_argument("get_stream request is empty"))??;
70            match req.value.unwrap() {
71                Value::Get(get) => get,
72                Value::AddPermits(_) => unreachable!("the first message must be `Get`"),
73            }
74        };
75
76        let receiver = self
77            .stream_mgr
78            .take_receiver(database_id, term_id, (up_actor_id, down_actor_id))
79            .await?;
80
81        // Map the remaining stream to add-permits.
82        let add_permits_stream = request_stream.map_ok(|req| match req.value.unwrap() {
83            Value::Get(_) => unreachable!("the following messages must be `AddPermits`"),
84            Value::AddPermits(add_permits) => add_permits.value.unwrap(),
85        });
86
87        Ok(Response::new(Self::get_stream_impl(
88            self.metrics.clone(),
89            peer_addr,
90            receiver,
91            add_permits_stream,
92            (up_fragment_id, down_fragment_id),
93        )))
94    }
95}
96
97impl StreamExchangeServiceImpl {
98    pub fn new(stream_mgr: LocalStreamManager, metrics: Arc<StreamExchangeServiceMetrics>) -> Self {
99        Self {
100            stream_mgr,
101            metrics,
102        }
103    }
104
105    #[try_stream(ok = GetStreamResponse, error = Status)]
106    async fn get_stream_impl(
107        metrics: Arc<StreamExchangeServiceMetrics>,
108        peer_addr: SocketAddr,
109        mut receiver: Receiver,
110        add_permits_stream: impl Stream<Item = std::result::Result<permits::Value, tonic::Status>>,
111        up_down_fragment_ids: (FragmentId, FragmentId),
112    ) {
113        tracing::debug!(target: "events::compute::exchange", peer_addr = %peer_addr, "serve stream exchange RPC");
114        let up_fragment_id = up_down_fragment_ids.0.to_string();
115        let down_fragment_id = up_down_fragment_ids.1.to_string();
116
117        let permits = receiver.permits();
118
119        // Select from the permits back from the downstream and the upstream receiver.
120        let select_stream = futures::stream::select(
121            add_permits_stream.map_ok(Either::Left),
122            #[try_stream]
123            async move {
124                while let Some(m) = receiver.recv_raw().await {
125                    yield Either::Right(m);
126                }
127            },
128        );
129        pin_mut!(select_stream);
130
131        let exchange_frag_send_size_metrics = metrics
132            .stream_fragment_exchange_bytes
133            .with_label_values(&[&up_fragment_id, &down_fragment_id]);
134
135        while let Some(r) = select_stream.try_next().await? {
136            match r {
137                Either::Left(permits_to_add) => {
138                    permits.add_permits(permits_to_add);
139                }
140                Either::Right(MessageWithPermits { message, permits }) => {
141                    let message = match message {
142                        DispatcherMessageBatch::Chunk(chunk) => {
143                            DispatcherMessageBatch::Chunk(chunk.compact_vis())
144                        }
145                        msg @ (DispatcherMessageBatch::Watermark(_)
146                        | DispatcherMessageBatch::BarrierBatch(_)) => msg,
147                    };
148                    let proto = message.to_protobuf();
149                    // forward the acquired permit to the downstream
150                    let response = GetStreamResponse {
151                        message: Some(proto),
152                        permits: Some(PbPermits { value: permits }),
153                    };
154                    let bytes = DispatcherMessageBatch::get_encoded_len(&response);
155
156                    yield response;
157
158                    exchange_frag_send_size_metrics.inc_by(bytes as u64);
159                }
160            }
161        }
162    }
163}
risingwave_compute/rpc/service/stream_exchange_service.rs

risingwave_compute/rpc/service/
stream_exchange_service.rs
